compostable films for agriculture - agrobiofilm

Edited by SILVEX, BIOBAG & ICSE

Compostable Films for Agriculture

The development of enhanced biodegradable mulch films. Case Studies:

Short cycle crops

Long cycle crops

Perennial crops

Agrobiofilm project receive funding from the European Union’s Seventh Framework Programme (FP7-SME-2007/2013) managed by Research Executive Agency (http://ec.europa.eu/research/rea) under the grant agreement number 262257.


PREFACE Prof. António Monteiro, President of International Society for Horticultural Science

INTRODUCTION

Paulo Azevedo, Coordinator of Agrobiofilm® project, SILVEX Managing Director

Copyright © Silvex 2013

Original Title Compostable Films for Agriculture, The development of enhanced biodegradable films for: melon & pepper, strawberry, vine

First published 2013Author’s Agrobiofilm ConsortiumCover & Interior Designer Joana CordeiroPrinted Guide Artes Gráficas

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form, or by any means, electronic, mechanical, photocopying, recording or otherwise without the prior permission in writing from the author of the texts and its editors.

www.agrobiofilm.eu

Contents

ACKNOWLEDGMENTS

PREFACE

Prof. António Monteiro, President of International Society for Horticultural Science

INTRODUCTION

Paulo Azevedo, Coordinator of Agrobiofilm® project,SILVEX Managing Director

CHAPTER 1. FROM POLYETHYLENE TO BIODEGRADABLE MULCH

1. Introduction2. Polyethylene Plastic Mulch Limitations3. Photodegradable / Oxo-degradable Plastics4. Biodegradable Mulches

CHAPTER 2. IS THERE A REAL COMPETITION BETWEEN BIOPLASTICS AND FOOD?

CHAPTER 3. AGROBIOFILM PROJECT

1. The Consortium 2. The Objectives3. The Raw Material4. Beyond The State of Art5. Description of Work

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CHAPTER 4. FIELD PERFORMANCE OF AGROBIOFILM MULCH IN CROP PRODUCTION

1. Short Cycle Crops – Melon and Bell-Pepper1.1 Introduction1.2 Mulch Application & Planting 1.3 Crop Growing and Harvesting1.4 Conclusions

2. Long Cycle Crops – Strawberry2.1 Introduction2.2 Mulch Application & Planting2.3 Crop Growing and Harvesting2.4 Conclusions

3. Perennial Crops – Vines3.1 Introduction3.2 Mulch Application & Planting 3.3 Mulch Impact on Soil Characteristics3.4 Ageing of Agrobiofilm® Under Field Conditions3.5 Vegetative Growth3.6 Production and Berry Quality Parameters3.7 Vine Training and Pruning3.8 Root Development3.9 Conclusions

CHAPTER 5. WASTE RECOVERY OPTIONS FOR MULCH FILMS

1. Polyethylene Mulch Removal and Disposal2. Agrobiofilm® Mulch Soil Incorporation3. Agrobiofilm® Mulch Soil Biodegradation

CHAPTER 6. LIFE CYCLE ASSESMENT AND POTENTIAL FOR WIDER APPLICATIONS OF AGROBIOFILM MULCH

1. Introduction2. Results and Discussion2.1 Bell Pepper LCA Environmental Impact2.2 Vineyard LCA Environmental Impact2.3 Muskmelon LCA Environmental Impact

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6363646686

878789929699101103106111

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115120125

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133133133135138

2.4 Strawberry LCA Environmental Impact2.5 Agrobiofilm® vs PE Mulch LCA Summary

3. Conclusions

CHAPTER 7. ORGANIC FARMING, ITS IMPORTANCE AND EU INCENTIVES TO BIODEGRADABLE MULCH FILM

1. Introduction2. Market Trends3. Organic Farms Weed Management4. EU Agri-Environment Measures

REFERENCES

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Acknowledgments

This book is the result of work carried out in three different countries during three years of investigation by multi-disciplinary teams of researchers and end-users.

In Portugal we would like to thank Professor Elisabeth Duarte and her team from Instituto Superior de Agronomia and to the University itself for their contribution and all the support and commitment to this project. We are also grateful to Professor António Monteiro for his support and encouragement.

In Spain our strawberry specialist Eng. Magdalena Torres from the Technological Centre ADESVA and her team were responsible for the work in long cycle crops. Her dedication and valuable input is reflected in the work produced in this book.

In France we were fortunate to have the commitment of Professor Emmanuelle Gastaldi and her team from Montpellier University. The groundbreaking work presented in this book is the result of persistent and exhaustive research carried out. We thank her for the meticulous work and detailed contribution to this entire project.

Professors John Hermansen and Kai Grevsen from Aarhus University contributed with a detailed LCA which we believe to be pioneering work in this field.

The work in the field and the positive attitude from the end users and their constructive contribution shows the “farmer” perspective. We are thankful to Flávia Damas (Hortofrutícolas Campelos), Olivier Mandeville (Châteaux Vaissière) and António Garrido Mora (EAGM).

Finally, we would like to take this opportunity to thank in the name of the Consortium to Carlos Rodrigues (our in-house Agronomist with a Masters degree in Horticulture and Viticulture), who had the gigantic task of being the project’s Scientific Coordinator, for all the valuable work and dedication to the Agrobiofilm® project.

Hernani de Magalhães Jørn Johansen Andrew Marsden Director at Silvex Director at Biobag Director at ICSE

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Preface

The use of plastic (polyethylene) films as soil mulches is widespread in horticulture production, especially in high value fruits and vegetable crops, but has well-known sustainability drawbacks and negative environmental impacts.

FP7 Agrobiofilm® Project entitled “Development of Enhanced Biodegradable Films for Agricultural Activities” has tested an alternative solution and paved the way for future replacement of conventional plastic films by biodegradable films. The project team has overcome to overcoming some technical barriers for broad scale introduction of biodegradable mulch films. The project tests provided the necessary knowledge about optimal material properties’, effect on crop performance, methods of use, and biodegradable conditions and timing.

The switching from conventional to biodegradable films is a complex challenge involving technical, commercial and socio-economic components. This change was successfully addressed by the holistic approach used in this project which involved SMEs and R&D institutions. I was pleased with the successful collaboration that was created within the project between research teams, film producers and end-users during the project. All of them were strongly committed to reach well defined innovative targets.

This Handbook evaluates the data produced by the project and includes valuable information about the use of biodegradable mulch films. Major sections of this publication deal with the evolution of films from PE to biodegradable, project description, the use of Agrobiofilm® in various crops, and biodegradation tests and timings.

This is a very useful publication which I specially recommend to policy makers, film producers and growers who want to get involved in the new era of sustainable mulch films in agriculture.

I conclude by congratulating the project leaders and the Handbook editors for the opportunity of bringing into public discussion such a relevant topic.

António A. MonteiroPresident of the ISHS - International Society for Horticultural Science

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Introduction

The European Union back in February 2012 adopted a new strategy to shift the European economy towards greater and more sustainable use of renewable resources.

Commissioner for Research, Innovation and Science Mrs. Máire Geoghegan-Quinn said: ”Europe needs to make the transition to a post-petroleum economy. Greater use of renewable resources is no longer just an option it is a necessity. We must drive the transition from a fossil-based to a bio-based society with research and innovation as the motor. This is good for our environment, our food and energy security and for Europe’s competitiveness for the future”.

More or less three years ago, when Silvex and Biobag started working together, we quickly realised that biodegradable and compostable plastics in agriculture was a great opportunity to make our mark in this business particularly in Southern Europe. The development of biodegradable mulch films backed up by sound scientific knowledge which could contribute positively to changing farming practices in the direction of sustainable agriculture was an interesting business proposition.

According to 2011 data the consumption of conventional mulch film in the EU is around 136,000 tonnes with biodegradable mulch reaching a tiny proportion that is no more than 1% to 2%. As we well know sooner or later the consequences of massively using fossil plastics will have a devastating impact in local communities where land is no longer productive or worst can no longer be used due to plastic contamination. There are already many landowners that do not allow tenant farmers to use conventional plastic.

The Agrobiofilm® project funded by European Union (FP7-SME-2010- Agrobiofilm® GA262257) is a perfect example of what is intended by the EU and sums up the commissioner words. In this handbook we have evaluated three years of work, mainly end results, concluded by Universities and Research Centers. By validating our biodegradable & compostable mulch films now branded Agrobiofilm® we believe to have created a product that is clearly a credible alternative to conventional fossil non-compostable plastic.

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This credibility has been definitely achieved and is supported by the valuable work carried out by our academia associates who helped us to go beyond the “state of the art” and to whom we would like to thank the dedication given throughout these years. We believe that this project is a good example of how the cooperation between companies/the “real economy” and universities/scientific investigation can be achieved.

It’s also the objective of this handbook to provide facts and real examples that help changing existing farming practices by more sustainable ones contributing thus to minimise mulching environmental impact.

Throughout the project we faced many challenges and we are sure that we will continue to do so after its conclusion. We also know that we will continue to learn more in the task of manufacturing more sustainable and economic biodegradable mulch films.

Paulo Azevedo Agrobiofilm® Project Coordinator, SILVEX Managing Director

CHAPTER 1From Polyethylene to Biodegradable Mulch

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CHAPTER 1

From Polyethylene to Biodegradable Mulch

1. Introduction

The term “plastic” comes from the Greek word “plastikos” which can be translated as “able to be molded into different shapes”. The plastics used today are made both from inorganic and organic raw materials such as carbon, silicon, hydrogen, nitrogen, oxygen and chloride. The basic materials most commonly used to produce plastics are extracted from oil, coal and natural gas (Seymour, 1989, cited in Kasirajan & Ngouajio, 2012).

Commercially plastics mulches have been introduced as production factor in vegetables since the 1960s (Lamont, 2005). Nowadays mulching is an ag-riculture practice of covering the soil surface under a crop with either clear or coloured films. Mulching can provide a number of benefits to crops such as the regulation of soil temperature the control of weed growth the prevention of water loss, the prevention of agrochemical leaching, the protection of leaves and fruits from possible soil diseases, protection of fruits from soil dirt, preventing the upper layer of soil from crusting (Briassoulis & Dejean, 2010) and the reduction of herbicide and pesticide use and frost protection.

These benefits led to an improvement in yield and quality parameters of crops. However the massive use of agricultural plastics raises a number of challenges mainly in end of cycle management as we shall discuss further ahead.

The increasing importance of plastics in horticulture and agriculture was highlighted in a recently published report where is stated that the European use (EU 27 plus Switzerland and Norway) of agricultural films totaled 545,000t in 2011 (figure 1.1). Silage film represents the largest segment with 45% of total volume, greenhouse film (classic greenhouses, macro and low tunnels, floating/direct covers) represents around 30% and mulch film represents the remaining 25%, which corresponded to 136,250t in 2011.

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Figure 1.1- The agricultural films market in Europe – adapted from plastics industry consultants Applied Market Information (AMI, Bristol/ UK; www.amiplastics.com). These market figures include the EU 27 as well as Switzerland and Norway.

In Europe the market is divided as follows (AMI Plastics 2010; AMI Plastics 2011; CIPA, 2006):

a. Nordic Region

Scandinavia has a market share of 7% of EU total plastics ≈18% being in mulch – 6,600t.

b. Germany, UK and Benelux

Germany has a market share of 11% of EU total plastics ≈34% being in mulch – 20,000t; Benelux has a market share of 6% of EU total plastics ≈28% being in mulch

– 9,000t;

Agricultural Films: European Consumption2011, by country (total: 545,000t)

© 2012 Plastics Information Europe Source: Applied Market Information

Other 16%

Poland 3%

Benelux 6%

UK 7%

Scandinavia 7%France 9%

Italy 21%

Spain 20%Germany 11%

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UK has a market share of 7% of EU total plastics ≈15% being in mulch –5,700t.

c. Mediterranean Europe

This region accounts for half of the European agricultural film consumption and is divided as follows:

Spain has a market share of 20% of total plastics being ≈32% in mulch - 35,000t; Italy has a market share of 21% of total plastics being ≈25% in mulch

- 28,600t; France has a market share of 9% of total plastics being ≈18% in mulch

- 8,000t; Portugal has mulched 23.000ha corresponding to around 4,500t.

2. Polyethylene Plastic Mulch Limitations

The main consequence of the large expansion in the use of conventional plastics for horticulture and agriculture is related to the handling of plastic wastes and its widely accepted negative environmental impact. In fact just a small percentage of the persistently increasing amount of agricultural plastic waste (thousands of tons produced each year) is currently recycled.

Due to the agricultural necessity of soil tilling mulch films are normally used for just one cultivation period being disposed at the end of each crop cycle. Recycling mulch films is time-consuming and expensive due to high removal labour cost. Furthermore these films are usually contaminated with pesticides, soil and crop residues which must be washed using large amounts of water before it can be recycled.

A serious harmful effect connected with the steadily growing use of plastics in agriculture concerns the parallel growing disposal problems of thousands of tons of agricultural plastics wastes produced every single year. Consequently huge portions of these are left on the field (figure 1.2A) with uncontrolled proliferation of landfills near farms or are burnt uncontrollably (figure 1.2B) by some negligent farmers. This situation can contribute to the release of dangerous substances with a negative environmental impact (Graci et all., 2008; Briassoulis, 2007).

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Aesthetic pollution and landscape degradation in regions of natural beauty represent an additional negative environmental impact even more so if tourism is economically relevant for the region. Additionally, another forbidden “disposal option” is burying mulch films in agricultural land (normally in a non-productive field) represents a forthcoming threat for an irreparable soil contamination and also possibly for the safety of the food produced in such fields. Both practices are illegal as per the Landfill and Incineration EC directives (Directive 99/31 EC and Directive 2000/76 EC).

Figure 1.2 – PE mulch film discarded (A) or burnt (B) in the field.

To sum up, the downside of conventional PE mulching is the need for its removal and correct disposal which will, nevertheless, always generate environmental issues. Following, the recent trend toward sustainable agriculture researchers and engineers are seeking environmentally friendly alternatives to conventional plastic mulch films. Biodegradable mulch films are among such alternatives and are considered “green alternatives” to PE since they are partly made from renewable biomass with its percentage expected to increase in the near future reducing reliance on non-renewable sources (e.g. fossil oil and gas). We are also aware that there are efforts to base the source of biomass on high yielding perennial crops that requires low inputs of water, fertilisers and chemicals for plant protection.

A B

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3. Photodegradable / Oxo-degradable Plastics

Photodegradable plastics are those reported to degrade by photo-initiated chemical reactions (Kasirajan & Ngouajio, 2012). The problem with these plastics is the incessant use of non-renewable petroleum-based resources and their questionable ability to totally decompose to carbon dioxide and water in soil without light emission (Halley et al., 2001; Zhang et al., 2008). Photodegradable mulch films have been tested for more than 20 years (Hemphill, 1993, cit in Kasirajan & Ngouajio, 2012). Results have been variable, with a lot of films presenting early degradation (Greer & Dole, 2003; Halley et al., 2001). Furthermore prostrate crops will cover mulch lines as they grow, minimizing UV light exposure and therefore inhibit film degradation. Moreover, mulch degradation is also reduced in areas that receive low solar radiation (Greer & Dole, 2003).

Oxo-degradable plastics are made of petroleum-based polymers such as polyethylene (PE), which contain additives (usually metal salts) that accelerate its degradation1 when exposed to heat and/or light. This practice of adding additives while extruding is a fairly common practice in the market and is quite popular in applications that have been challenged for its high environmental impacts, such as carrier bags. These are often marketed as “degradable”, “oxo-degradable” or “oxo-biodegradable” implying a reduced environmental impact at the point of disposal compared to common plastics without the additive. The British Department for Environment, Food and Rural Affairs (DEFRA) published a report back in 2009 based on a study carried out by the Loughborough University that assessed the environmental impact of oxo-degradable plastics across its life cycle. The main purpose was to review published literature and engage with key stakeholders to understand what happens to polymers and metal salts after the material starts to degrade and to assess whether this has a beneficial or negative effect on the environment compared with plastics that do not contain the additive.

1. Degradation of oxo-degradable plastics occurs through a chemical process called oxidative degradation, where the molecules are broken down into shorter lengths by oxygen, ultra-violet light and/or heat.

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The study also analysed evidence behind the marketing claims being made about oxo-degradable plastics in particular assessing the evidence that these materials degrade or biodegrade and under what conditions and timeframe.

The final report 1 (DEFRA, 2010) concluded that incorporating additives into PE based plastics to accelerate their degradation does not improve the environmental effects of plastics because:

1. The length of time it takes for oxo-degradable plastics to first degrade and then to biodegrade cannot be predicted accurately depending on the environmental conditions to which they are exposed. Although it is likely that oxo-degradable plastics will start to degrade between 2-5 years in the UK, it is unclear how long the material takes to biodegrade. Oxo-degradable plastics are not compostable, the term “biodegradable” applied to these plastics is meaningless and potentially confusing to users when choosing how best to dispose of the material.

2. Oxo-degradable plastics may have undesirable consequences on disposal facilities and on the natural environment. The concentration of metal additives contained in the plastic is low they are unlikely to significantly increase concentrations which occur naturally in the environment but there is concern about the possibility that insect and animals can ingest plastic fragments. Oxo-degradable plastics are not appropriate for inclusion in conventional recycling systems and available evidences suggest that it does not degrade in aerobic conditions.

3. The best means of disposal for oxo-degradable plastics is incineration or if not available then landfill is the next best option. Both of these options make the “degradable” property of oxo-degradable plastics irrelevant.

According to Kasirajan & Ngouajio (2012), the degradation of oxo-degradable plastics is a result of oxidative and cell-mediated phenomena, either simultaneously or successively. Therefore, oxo-degradable mulches behave similary to photodegradable mulches since the buried part does not suffer degradation and needs to be exposed to light and air.

2. http://randd.defra.gov.uk/Document.aspx?Document=EV0422_8858_FRP.pdf

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An alternative to these photodegradable/oxo-degradable plastics may be the use of biodegradable films made of corn starch and other biodegradable polymers (Martin-Closas et al., 2003) such as Agrobiofilm® mulch, since they are broken down by the action of humidity and microorganisms decomposing completely into CO and water (Albertsson

& Huang, 1995).

4. Biodegradable Mulches

Biodegradable plastics are present today in various sectors of the economy, but only a very limited amount of this are used in agriculture. In 2007 the global biodegradable plastics used in Europe was around 30,000t representing only 0.06% of the total market (Briassoulis & Dejean, 2010).

For an environmentally friendly agricultural activity an alternative strategy to the polyethylene-based mulch is to use bio based agricultural raw materials. In the Agrobiofilm® project we use a recent Mater-Bi® formulation characterised by a high content in renewable feedstocks.

Biodegradable materials are decomposed in the soil by the action of microorganisms such as bacteria, fungi and algae. One of the immediate advantages of using biodegradable products is that they can be buried directly in the soil (e.g., together with crop residues) thus no removal from the field is required at the end of crop cycle.

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CHAPTER 2Is There Real Competition Between Bioplastics and Food?

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CHAPTER 2

Is There Real Competition Between Bioplastics and Food?

The development of bio-fuels in the last decade generated a world debate about the use of biomass for industrial purposes. The strong price increase in agricultural commodities in 2007 was suggestively linked to the growing development of biofuels industry. However according to market analysts (Ganapini, 2013) this price hike was primarily due to several other factors such as:

The dramatic rise in oil prices led to a significant increase in the cost of grain due to higher costs in fertilizers, storage, transport and distribution;

Rising demand in developing countries, particularly India and China; Diet change in emerging countries (more meat consumption);

Market speculation;

Poor harvests in some countries;

World population increase.

Since raw materials used to produce bioplastics are totally or partly renewable resources cultivated in farmland it is important to address the question “Are we substituting land for food production for non-food products (energy, materials, etc.)?”

A study published by the European Bioplastics 1 addresses such issue and refers that the land needed to produce all type of bioplastics in the world in 2011 was only 0.006% of global agricultural area (figure 2.1).

1. http://en.european-bioplastics.org/wp-content/uploads/2013/publications/EuBP_FactsFigures_bioplastics_2013.pdf

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Figure 2.1: Land use for Bioplastics 2011 and 2016 (adapted from Bioplastics-facts and figures, 2013).

This can off course, change according to the crop used, its productivity, the effective biobased content of bioplastics and the real market volume that is substituted but the scale will remain unchanged even taking into consideration a predictable increase of bioplastics production in the near future. The land used could rise to 0.022% of total arable area by 2016.

Since Agrobiofilm® project is focused in the European market and mulch being one of three main categories of agricultural plastics (ensilage film and greenhouse film being the other two) we considered to be important to show here the ultimate scenario of what is the amount of land needed to replace all PE based mulch by Agrobiofilm® mulch.

Global land area13.4 billion ha = 100%

Global agricultural area5 billion ha = 37%

GLOBAL AGRICULTURAL AREAPasture3.5 billion ha = 70%*Arable land1.4 billion ha = 30%*

Food & Feed1.29 billion ha = 27%*Material use100 million ha = 2%*Biofuels55 million ha = 1%*

Bioplastics2011: 300,000 ha = 0.006% *2016: 1.1 million ha = 0.022% *

* In relation to global agricultural area.

Source: European Bioplastics / Institute for Bioplastics and Biocomposites (October 2012) / FAO

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Considering the latest data from AMI (2011) agriculture and horticulture activities are responsible for 545,000 t/year of plastics used in greenhouse, ensilage and mulch, which in turn accounts for 25% of total volume.

In order to produce 136,250t/year (25% of total volume) we can estimate we would need, considering the renewable content of raw material used to produce Agrobiofilm® is 100% corn starch (which is not), 0.006% of farm land to cover all this demand.

The numbers are simple! Let’s assume that a 100% rate from raw material to ended molten product to produce 136,250t of Agrobiofilm® mulch we would need 136,250t of starch. If we consider about 66% of starch content in the grain (Ganapini, 2013) we conclude that 1.0t of starch (dry matter) is extracted from about 1.5t of corn grain (dry matter). Thus to produce 136,250t of starch (dry matter) we need 206,440t of grain (dry matter). This amount of grain is harvested from 31,278 hectares grown with corn, considering an average European corn productivity of 6.6t grain/ha 1.

This value is about 0.006% of the total European agricultural land (474,8Mh)2, which can be proportionally visualised, for better comprehension as a comparison between the size of a grape berry in relation to the Eiffel Tower.

We must also consider that Agrobiofilm® mulches are 40% to 50% thinner than PE (e.g., for melon normally PE mulch is 25-30µm and Agrobiofilm® is 12-15µm; for strawberries PE is 30-35µm and Agrobiofilm® is 18-20µm) with a consequent reduction in the quantity used every year we could in theory reduce our estimates by 30% to 40% of the total amount of 136,250t/year.

This quick calculation clearly demonstrates that even considering ultimate scenarios the land requirement for production renewable raw materials for the European consumption of mulch film is irrelevant in terms of arable land occupied and therefore cannot be considered any threat to the actual food supply.

2. http://faostat.org/site/567/DesktopDefault.aspx?PageID=567#ancor.

3. http://en.worldstat.info/Europe/Land.

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CHAPTER 3Agrobiofilm Project

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CHAPTER 3

Agrobiofilm Project

This holistic project required a group of entities that could manufacture biodegradable mulch films according to desired pre-designed characteristic, end users who understood farming conditions and could apply experimental films to existing crops in real field conditions and RTD teams that could measure and study its results.

The manufacturers alone had the capability to produce and market biodegradable mulch but they lacked the expertise to address significant scientific barriers and needed to be assisted with the required technological development. Hence the procurement of cross-disciplinary scientific knowledge and collaboration with several European RTD performers was essential. This combination of entities formed a value chain that brought together agricultural (primary sector) to industry (secondary sector) in sharing knowledge and results that were constantly monitored and evaluated by Academia.

1. The Consortium

The Agrobiofilm® consortium, on the SME manufacturers’ side, consisted of the following companies:

SILVEX – Indústria de Plásticos e Papéis, S.A. A Portuguese SME manufacturer of conventional, recycled and biodegradable plastics strategically committed to the development of sustainable products (www.silvex.pt);

BioBag International AS A Norwegian SME with world leading expertise in manufacturing and commercialising certified compostable and biodegradable plastics (www.biobagworld.com);

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ICS Environnement A French SME with wide market knowledge of biodegradable plastic applications (www.biobag-france.com).

The RTD Performers were carefully selected on the basis of their expertise and mutual complementarily but also on their ability and experience of cooperating with industrial partners in industry led collaborative projects.

On the RTD side:

Instituto Superior de Agronomia A 160 year old Portuguese Agronomical University specialising in agronomic and environmental science (www.isa.utl.pt);

Asociación para el Desarrollo del Sistema Productivo Vinculado a la Agricultura Onubense A leading Spanish Technological Center (www.citadesva.com);

Unité Mixte de Recherches “Ingénierie des Agropolymères et Technologies Émergentes” A French RTD performer, specialist in biodegradable materials; from Montpellier University 2 (umr-iate.cirad.fr);

Aarhus University A Danish University dedicated to agroecology, horticulture and environment assessments (www.au.dk/en/).

Finally the consortium includes, on the end-users side the following SMEs:

Hortofrutícolas Campelos - Portuguese commercial producers organisation, producer of fruits and vegetables (www.hcampelos.pt);

Olivier Mandeville - French winegrower (www.chateauvaissiere.fr);

Explotaciónes Agrarias Garrido Mora - a Spanish strawberry producer.

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In conclusion, based on the overall history and profile, the consortium partners collectively constituted a balanced group capable of achieving scientific and technological objectives and market breakthrough that could be applied to the finished products. All partners had a strategic interest in the project and were mutual complementary. Specifically there was no overlap between SMEs forming the value chain since they are part of a joint venture agreement for exploitation of different markets. Regarding the RTD performers the exchange of experiences in the same field but for different climates, crops and regions were envisaged as an advantage with a proactive cross involvement to reduce oversight and increase quality control in all work packages.

2. The Objectives

Purposely, the consortium idea was to enhance mulch films based on biodegradable raw materials customised to specific crops and regions through the optimisation of manufacturing processing using state of the art technology so that the end product could be both economical and technical viable while considering possible positive effect on crop yield and quality, pests and/or disease control, soil preparation and fertilisation.

The consortium therefore wished to address a major market opportunity through the development and performance demonstration of mulch films that would be able to fulfill three main requirements:

To be environmentally friendly;

To be compliant with common farming methods;

To match or improve crops performance as expected in the case of conventional polyethylene based plastic films.

Apart from concrete objectives, Agrobiofilm® project results can significantly promote the uptake of highly productive and environmentally friendly farming practices among end-users.

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The project could also increase the competitiveness of the participating manufacturers by providing these SMEs with a state of the art platform to develop competitive biodegradable mulch films and therefore widening the applicability of certified compostable products to new markets.

3. The Raw Material

The raw material used in this project is a recent developed Mater-Bi® grade, characterised by a higher content in renewable feedstock as compared to other biodegradable films currently being processed for mulch applications. Chemically it is characterised as a aliphatic/aromatic co-polyester with a starch matrix, which is nothing new in itself, widely reported in literature and object of thorough research. However, the novelty of this new polymer formulation brings new questions regarding processing optimisation and its application to agriculture needs which could only be answered through extensive research. We have compared these films against conventional mulch (polyethylene based) and other biodegradable polymers that are already in use in the market. The agronomic performance of these biodegradable mulch films (accordingly referred, both as ABF and Agrobiofilm®) was then finally assessed through field experiments conducted on four selected crops known to need specific requirements in terms of film properties and life time: peppers, melons, strawberries and vines.

4. Beyond The State Of The Art

The overall objective of Agrobiofilm® project was to develop biodegradable mulch films, scientifically test and validate its performance during the du-ration of the 36 month project with the purpose to extend its application to a broader scale and a wider range of crops and end-users. The properties of these innovative starch based mulch films were improved compared to existing mulch films (made either of polyethylene or of biodegradable polymers such as older Mater-Bi® formulations). The initial goals were:

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Agrobiofilm® will be better adapted to the farmer’s needs since it is customised to the crop. The aim is to match mulch life cycle with crops life cycle;

Agrobiofilm® will be more efficient to modulate light transmission and reflectance due to colour additives that will be added to the raw materials. Besides black, other mulch colours tested were white/black, silver/white/ black, transparent and green;

Agrobiofilm® will be more eco friendly with a better biodegradable behaviour compatibble with different soil quality (horticulture/viticulture) and type of exposure related to farming practice (burying in soil after harvest or let loose at soil surface);

Agrobiofilm® mulches will be produced more economically compared to other biodegradable mulch films, due to a reduced film thickness and also to the incorporation of scraps and optimised specific processing conditions;

Agrobiofilm® in a agronomic point of view will be at least as efficient, as existing PE mulch films and other biodegradable polymers (weed control, water saving, pest & diseases control, yield, quality, earliness of harvest).

The ability to prove these characteristics will help us to demonstrate the benefits of using Agrobiofilm® mulch films to end-users.

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5 - Description of Work

The work plan for Agrobiofilm® consisted of seven work packages schematically presented in the figure below which have been designed to ensure rapid technology uptake and broad involvement among the SMEs.

Figure 3.1 - Workplan for Agrobiofilm® project.

Work package one ensured coordination and progress between consortium members and consisted in overall project management such as resource allocation, work plan changes, communication flow and work schedule.

RTD operational activities were divided in WPs 3, 4, 6, 7 with the objective to establish grounds, for testing and to enhance specifications for the development of new films.

An exhaustive analysis of crops and end-users requirement, the identification of manufacture’s technological limitations and the definition of a common test methodology was covered by WP3.

WP1 - Project management

WP4 - Development of new BMFformulations

WP5 - Implementation of fields tests

WP6 - Monitoring field tests

WP7 - Integrated assessment andperformance validation

WP

3 -

Ag

ron

om

ic r

equ

irem

ents

an

d s

pec

ifica

tio

n a

nal

ysis

WP

2 - Dissem

inatio

n an

d T

rainin

g

39

The essence of WP4 involved characterisation of the new biodegradable mulch films, which also included activities for process optimisation.

WP5 covered demonstration activities designed to test the viability of the new mulch films carried out at the participant end-users sites. The implementation of the field tests was done for different crops (melon, pepper, strawberries and vines) in different regions (Ribatejo – Portugal; Huelva – Spain; Languedoc – France). All tests were performance in real field conditions with real farmers following his usual practices.

The performance tests was covered in WP6 which comprised detailed monitoring of several parameters so to understand the influence of field conditions on the films performance and its influence in the crops.

Finally, WP7 was dedicated to the integration of all the knowledge acquired through a life-cycle analysis and performance/cost-efficiency validation.

Parallel to these activities WP2 was designed with the objective to disseminate project results to tackle the lack of scientific end-users know-how which has been identified as a major barrier for market penetration.

CHAPTER 4Field Performance of Agrobiofilm Mulch in Crop Production

1. Melon and Pepper

2. Strawberry

3. Vines

43

CHAPTER 4

Field Performance of Agrobiofilm Mulch in Crop Production

Compared with the performance of conventional PE mulch films the introduction of biodegradable mulch films in agriculture brought new expectations to end users. Nevertheless these new materials bear several concerns by farmers regarding not only the production yield and quality but also in relation to the changes in the common agriculture practices.

One of the main concerns in field trials execution, during all Agrobiofilm® project, was to maintain conventional agricultural practices regarding soil preparation and the use of organic and mineral fertilisers without compromising the biodegradable mulch film mechanical integrity. End-users expected to use their own machinery without major adaptations whilst not compromising the biodegradable mulch behaviour such as tear resistance and tear propagation during its application. This new type of mulch also allows for the possibility of using the traditional drip tape irrigation, it does not require additional work associated with preparation, its application and soil incorporation.

44 Agrobiofilm®

1. Short Cycle Crops - Melon and Bell-Pepper

1.1. Introduction

In short-term crops end-users expectations are mainly focused on the physico-chemical characteristics of biodegradable mulch films that should be kept intact until the end of the crop cycle to fulfil the main goals of mulching.

Muskmelon (Cucumis melo L.) is an annual, herbaceous, prostrate plant that spreads in all directions. As is characteristic of the cucurbits the roots spread out laterally and vertically to considerable depths. These species tolerate very well the heat but are highly sensitive to the slightest frost in spring or autumn. It requires a minimum average soil temperature of 15.5°C with an optimum mean temperature for growing ranging from 18-24°C and a high average temperature of 32°C. Muskmelons do not tolerate poorly drained soil conditions and can quickly wilt and die if such conditions persist.

45

SHORT CYCLE CROPS - MELON AND PEPPER

The root system gets damaged even when a flash flood covers the soil for more than few hours.

Commercial production systems usually use raised beds covered with plastic mulches with wide variations between bed distance (1.2 – 3.7m) and between plants in the same row (0.6 – 1.8m). Some systems use two rows within the same bed.

Growers widely use plastic mulch with the main objective to increase soil temperature which is of utmost importance. The root-zone temperature (RZT) of any plant greatly affects its growth rate and nutrient absorption. Economically important vegetable crops such as peppers and muskmelons have all different optimum RZT for maximum growth. Muskmelon seed-lings are very sensitive to low soil temperatures as their RZT threshold for optimum growth seems to be 35 to 36°C (Stoltzfus et al, 1998).

Since soil temperature is a major environmental variable which directly influences crop development, its increase, caused by the application of mulch film in muskmelon crops, is responsible for an earlier development. This effect is achieved reducing time to anthesis and harvesting and by increasing fruit yield due to larger leaf area and faster rate of plant development. Transparent film is preferable because it induces higher temperature increase in comparison with black film. However transparent film is much less effective in weed control than black film causing competition for nutrients, moisture and space between the weeds and the crop.

The effect of the film is critical during crop development and its integrity should last for approximately 3 months. Thereafter the film thermal effect is lost due to canopy coverage.

Bell pepper also known as Sweet Pepper or Capsicum is a cultivar group of the species Capsicum annuum L. Cultivars of the plant produce fruits in different colours, including red, yellow and orange. This specie requires a long warm and frost-free growing season (4 - 5 months).

46 Agrobiofilm®

The optimum temperature for plant growth is 24 - 27°C with a maximum of approximately 32°C. Bell peppers can be grown in many types of soils ranging from sandy to heavy clay, but the best quality fruits are usually produced in light soils. This crop prefers a pH ranging from 6-7 (Farooqi et al, 2005).

Peppers grow well on raised beds covered with black or silver plastic mulch. However, since the main priority is weed control black films are therefore the most commonly used in this crop. Black film provides an effective weed control but is less efficient in increasing soil temperature when compared to transparent films. Peppers produce a much sparser canopy than melons, which promotes the establishment and growth of weeds. Due to the shallow crop canopy, the film should provide an effective weed control for 4 to 5 months which is about the time required to harvest. For a maximum benefit film should be in close contact with the soil and the planting holes have to be the smallest as possible to avoid light penetration beneath the film. Optimum plant growth and yields are obtained with drip irrigation, which also allows growers to apply injection-based fertiliser during the growing season.

Generally the plantation is done with approximately 25,000 – 35,000 plants per hectare in double rows 35–45cm apart on plastic mulched beds with 40–60cm between plants in the row and with the beds usually spaced 1.5m.

One of the major problems in the production of peppers are insects. Crop losses can be caused by aphids, flea beetles, pepper maggots, thrips, and European corn. Several diseases can attack pepper plants including bacterial leaf spot, phytophora blight, anthracnose fruit rot, bacterial soft rot and viruses such as potato virus and tobacco mosaic virus leading to serious crop losses (Orzolek et al, 2010).

47


1.2. Mulch Application & Planting

Soil preparation to lay Agrobiofilm® mulch is a key operation and an important factor. Good film performance during all crop cycle is assured by a correct soil preparation. Bellow we can see in figure 4.1 a good soil preparation.

Figure 4.1 – Soil preparation for Bell pepper (A) and muskmelon (B).

The soil intended to be covered with mulch film must be preferably loose and refined without stones or residuals from preceding crops (Figure 4.2) which can tear and damage the film. This may result in heat loss and facilitates weed development. Moreover these films are more exposed to wind action, tearing or holes and which can initiate an undesirable early degradation.

Figure 4.2 – Soil covered by stones (A) and soil with residues of last crop (B).

A B

A B

48 Agrobiofilm®

Film application can be performed with the same implement used for the traditional PE plastic mulching films. However depending on the equipment it is advisable to reduce the tension of the roll during the operation. The location of the irrigation tubes slightly under the soil favors film integrity and provides good protection from heat. But it is important not to damage the structure of Agrobiofilm® during its application together with drip irrigation tape. As shown in the figure below drip tape irrigation is pressing the mulch film and drippers can produce small holes.

Figure 4.3- Mechanical application of mulch film and tape irrigation. Preferably, irrigation tube should be placed slightly under the soil avoiding the pressure of drip irrigation on the mulch showed on figure detail.

49


If these holes are distributed regularly along the film it may lead to a deterioration starting point and film integrity can be compromised (figure 4.4).

In automatic or semiautomatic planting equipment it is advisable to adjust the components in contact with mulch (figure 4.5) to avoid an early degradation of Agrobiofilm® mulch as shown in figure 4.5 C. As shown in figure 4.6 this slight adjustment ensures the good performance of Agrobiofilm® mulch without compromising the quality of the plantation. Normally to finalise the plantation a small portion of soil is placed manually at the base of each plant (figure 4.7). The practice shown in the figure (a person walking on the top of mulch) should be avoided. Moreover as seen in the figure the quality of the soil preparation was not ideal (large and rough clods) but Agrobiofilm® worked perfectly also in these conditions.

Figure 4.4- Mulch degradation along the drip tape irrigation, as result of damage during film application.

50 Agrobiofilm®

Figure 4.5- Semi-automatic planting equipment. Press wheels (A) and metal blades (B) must be adjusted in order to avoid mulch deterioration at planting time (C).

Figure 4.6- A slightly adjustment allowed a perfect dual operation- laid down Agrobiofilm mulch together with planting muskmelon.

Figure 4.7- Bad soil preparation and worker walking on top of Agrobiofilm mulch.

A

B

C

51


1.3. Crop Growing and Harvesting

1.3.1.Muskmelon Soil monitoring

The soil in the field trials is a loamy-sand soil (SRA, 1977) and its physical and chemical characteristics were assessed before land preparation, during the film application and several times after the Agrobiofilm® was ploughed into the soil. All the parameters analysed did not show any difference caused by the Agrobiofilm® biodegradation.

Table 4.1 - Soil Monitoring (temperature and water volume content) - Muskmelon (1st and 2nd cycles)

Values followed by the same letter are not significant different with an α=0.05.

In the muskmelon case for the first cycle the soil temperature and water volume content (WVC) under the different plastic films showed some differences. The soil temperature under the ABF1 modality was around 0.7 °C lower and the WVC was around 3.3 % higher than in polyethylene (PE 1) – Table 4.1.

In the second cycle the soil temperature was not significantly different within the modalities tested (PE1, ABF1, ABF2 and ABF3).

1 Trial(2010)

2 Trial(2011)

st

nd

Modality Temperature (C)

Soil Water Content (%)

PE 1

ABF 1

PE 1

ABF 1

ABF 2

ABF 3

25.7

25.0

24.4

24.1

24.3

24.4

16.6

19.9

10.6

15.7

10.0

11.9

a

b

a

a

a

a

a

b

a

c

a

b

52 Agrobiofilm®

The ABF1 showed higher WVC (around 5.1 % more than the PE1) and ABF3 the second highest around 1.3 % more than the PE 1. The PE 1 and ABF2 were the tested modalities with less WVC and showed no differences between them. These results are in accordance with those achieved during the first trial. When comparing ABF1, ABF3 and PE1 mulch (films with the same colour) it was expected to find higher soil temperatures under PE because of Agrobiofilm® higher permeability characteristics which appears to promote a greater soil water vapour transfer through the film leading to a decrease in soil temperature. However this result was not verified as no significant differences were observed (table 4.1). It was also expected that soil under PE would have higher WVC but this was not verified in the field trials. In the case of WVC there were some interesting results that indicate Agrobiofilm® may reduce water consumption. In open field conditions, the overnight dew or rain may penetrate Agrobiofilm® and can be the explanation for the increase of soil WVC, as verified in the strawberry test (figure 4.8).

Figure 4.8 – Effect of different mulch permeability observed after rain. Same effect was observed with dew. In open field conditions, this can lead to reduce irrigation costs.

Agrobiofilm Conventional PE

53


Pest and diseases

In the first cycle (2010) major pests and diseases were surveyed. In relation to pests, the population of Aphis gossypii reached its economic threshold in June to justify insecticide treatment. The initial population of the pest came randomly and spread similarly affecting equally plants on Agrobiofilm® and conventional PE. In June there were symptoms of gummy stem blight that affected less than 1 % of the plants. The foci appeared scattered through the countryside and spreading took place along the lines of culture. Again the disease affected in the same way plants on Agrobiofilm® and conventional PE.

In the second cycle (2011) the presence of pests and the incidence and severity of diseases were evaluated according to the methods used in the previous year. There were some small focuses of aphids (Aphis gossypii) the incidence of fusarium (Fusarium oxysporum) was high but there was no difference between films both for pests and diseases.

Crop yield

As shown in Table 4.2 in the first year, PE1 modality had an average marketable yield of 35.6 t/ha with 22 % of non-marketable fruits while the Agrobiofilm® tested (ABF 1) had an average of 32.6 t/ha (not statistically different from the previous) with a 23 % of non-marketable fruits.

54 Agrobiofilm®

Table 4.2 – Muskmelon production in the first and second cycles with % of non-marketable fruits and marketable yield.

Per trial and column, values followed by the same letter are not significant different at α=0.05.

The production in the second year was a little lower due to an unknown physiological disorder that equally affected all the modalities. The modalities studied were PE1, ABF1, ABF2 and ABF3 and the marketable yields were between 20.5t/ha and 23.4 t/ha. The non-marketable fruits had higher percentages (Table 4.2). The average production of muskmelon in Portugal is around 25 t/ha (OMAIAA, 2012) which indicates that in the first year the production was much higher (ABF 1 with 32.62 t/ha) than the average and in the second cycle it was a little lower.

Crop fruit quality

In relation to quality parameters for muskmelon crop no significant differences were detected between modalities in both cycles (Tables 4.3 and 4.4). However if we consider all the parameters a tendency for better results can be observed in ABF1.

1 Trial

2 Trial

st

nd

Modality Non Marketable

(%)

Marketable Yield (t/ha)

PE 1

ABF 1

PE 1

ABF 1

ABF 2

ABF 3

22.0

23.0

57.1

58.5

35.0

57.3

35.60

32.62

23.40

21.32

20.49

23.24

a

a

a

a

a

a

55


Water

(g/10

0g)

En

ergy

(kcal/10

0g)

Pro

tein(g

/100

g)A

shes

( g/10

0g)

Fiber

(g/10

0g)

Carb

o -

hyd

rates( g

/100

g)

Acid

ity(g

/100

g)T

otal

Sug

ar ( °B

rix)

To

tal L

ipid

(g/10

0g)

PE

1

AB

F 1

Modality

aa

aa

aa

aa

ab

aa

aa

aa

aa

91.15

92.4

0

33.3

29.7

0.8

5

0.75

0.10

0.11

0.4

5

0.4

0

0.20

0.28

7.45

6.34

10.1

9.7

0.72

0.9

8

Tab

le 4.3 –

Mu

skmelo

n fru

it qu

ality analysis fo

r the fi

rst cycle.

Per co

lum

n valu

es follo

wed

by th

e same letter are n

ot sig

nifi

cant d

ifferen

t with

an α

=0

.05.

Tab

le 4.4

- Mu

skmelo

n fru

it qu

ality analysis fo

r the seco

nd

cycle.

Per co

lum

n valu

es follo

wed

by th

e same letter are n

ot sig

nifi

cant d

ifferen

t with

an α

=0

.05.

An

tioxid

ant

capacity

( mM

Tro

lox/10

0g)

Ph

eno

lics(m

g G

alhic A

c/100

g) To

tal Sug

ar( °B

rix)

PE

1

AB

F 1

AB

F 2

AB

F 3

0.9

0.4

0.7

1.3

22.7

27.4

26.1

17.0

12.2

12.7

11.8

11.5

aaaa

aaaa

aaaa

Modality

56 Agrobiofilm®

Film Performance

The mechanical behaviour of mulches was evaluated visually by taking photos along the crop cycle. In both cycles mulches showed an adequate resistance until near the end of crop cycles and did not compromise development. At the time of incorporation about 2 months after the end of cycle it was possible to observe some physical degradation in the material. However in the presence of nut sedge (Cyperus rotundus L.) large infestation as shown in the next figure, a normal Agrobiofilm® blend for muskmelon was not effective in weed suppression. Although Agrobiofilm® had proven to perform equal or better than PE that could not be observed in the fields that had a significant presence of this particular weed.

Figure 4.9 – Third cycle of trials in muskmelon on Ribatejo, Portugal. Picture recorded at June 6th, showing high infestation by nut sedge and the destruction of the mulches by this weed.

57


1.3.2.Bell-Pepper Soil Monitoring

The soil from the field trials is a loamy soil (SRA, 1977) and its physical and chemical characteristics were assessed before the land preparation during film application and several times after the film being ploughed to the soil. All the parameters analysed did not show any difference caused by the biodegradation of Agrobiofilm® mulches.

Pest and Diseases

In the first cycle, evaluation of pests and diseases was made visually. No damage was caused by pests. In the second cycle weekly samplings were made by shaking vigorously the flowers from the 10 plants selected in each replication during the flowering period.

The pest monitored were thrips (Thysanoptera – Frankliniella occidentalis) which are the most notorious pest on this crop. A total of nine samples were taken to assess the insect population. Differences on the several modalities were noted but no associated damage was registered. The bare soil modality (as a term of comparison) had the highest insect population mainly explained by the fact that more weeds grow around the bell pepper plants (table 4.5).

Table 4.5 – Average number of thrips (Frankliniella occidentalis) per modality. Second Bell peppers trial.


ABF 11Modality

Thrips/30 plants

109.9 123.5 83.0 122.2 116.0

ABF 10 ABF 7 ABF 9 ABF 8 ABF 6

ab ab ab ab 119.5aba

NF 2 Bare Soil

97.9 192.5a b

58 Agrobiofilm®

Crop Yield

In both cycles crop harvest was divided in two phases the unripe and the ripe fruits and production was calculated as total of both phases.

Table 4.6 – Bell-pepper production in the 1st and 2nd cycles

Per trial values followed by the same letter are not significant different with an α=0.05.

1 Trial 2010st

Modality Non Marketable

(%)

Marketable Yield (t/ha)

PE 2

ABF 6

ABF 6

ABF 7

ABF 8

ABF 9

ABF 10

ABF 11

NF2

Bare Soil

6.0

7.0

9.5

2.9

4.6

7.5

4.3

11.9

12.2

15.4

a

a

bc

d

bc

c

bc

d

a

a

17.2

16.9

6.3

5.3

5.4

3.8

5.0

6.8

2.8

4.5

55.8

59.1

54.0

74.3

58.8

67.3

56.5

76.1

47.8

44.3

73.0

76.0

60.3

79.6

64.2

71.1

61.5

82.9

50.6

48.8

2 Trial 2012nd

Unripe Ripe Total

59


In the first cycle no differences were detected between PE2 and the ABF6 with a marketable yield of 73.0 and 76.0 t/ha respectively.

In the second cycle significant differences were detected, with the bare soil having the worst yield (48.8 t/ha) and the best yields were obtained in ABF11 and ABF7 with 82.9 and 79.6 t/ha respectively (Table 4.6).

In the first cycle the studied modalities did not show a great difference in the non-marketable fruits with 8.3% and 8.9% in PE 2 and ABF6. The highest percentage being almost 15.4% of non-marketable fruits was de-tected in the bare soil on the second cycle.

Crop Fruit quality

In the first cycle no differences were registered between the modalities in the studied parameters.

The modalities in which the quality parameters revealed the best results in the second cycle were NF 2, bare soil, ABF6 and ABF8 in this order, which is directly related to the lower production achieved in these modalities. Interestling, in pulp thickness evaluation which represents an important parameter for the processing industry the best results were obtained in ABF6 (Table 4.7).

60 Agrobiofilm®

Mo

dal

itie

s

An

tiox

idan

t act

ivit

y

( µm

ol T

rolo

x/10

0g

)

Ph

eno

lics

(mg

CA

E/1

00

g)

To

tal s

ug

ar

(°B

rix)

Aci

dit

y

(g c

itri

c ac

id/1

00

g)T

hic

knes

s

(mm

)u

nri

pe

r

ipe

un

rip

e

rip

eu

nri

pe

rip

eu

nri

pe

r

ipe

rip

e

PE

2

AB

F 6

AB

F 6

AB

F 7

AB

F 8

AB

F 9

AB

F 10

AB

F 11

NF

2

Bar

e so

il

161.

1

150

.0

89.3

78.2

103.

1

30.0

31.2

38.1

128.

5

104.

5a a bc a cd a a a e d

520

.9

850

.6

815.

9

717.

0

829.

6

867.

5

812.

8

879.

3

18.6

20.1

61.3

77.0

67.5

60.3

61.1

65.5

680

.8

69.4

129.

5

131.

0

128.

4

114.

6

108.

3

133.

5

133.

5

171.

6

4.3

5.0

4.2

4.2

4.2

4.1

3.8

4.1

4.6

4.4

6.8

6.7

6.7

5.8

6.0

6.2

7.3

7.6

0.1

6

0.1

1

0.1

3

0.1

1

0.1

1

0.0

9

0.1

5

0.1

1

0.2

2

0.1

8

0.2

5

0.1

8

0.2

3

0.2

3

0.2

1

0.2

0

7.4

6.6

5.2

6.4

6.1

5.6

7.1

5.5

- -- -

- -- -

- -- -

d bc ab e ab c a c

a a ab e cd a ab c f bc

a a a b b a a c

a a a a a b d b e c

e d d a b c f c

c a e a a b bc a

abd

c b c ab ab ad cd

f def

a cde

bcd

abc

ef ab

1 C

ycle

2 C

ycle

st nd

Tab

le 4

.7 –

Bel

l-p

epp

er f

ruit

qu

alit

y an

alys

is f

or

the

firs

t an

d s

eco

nd

cyc

les

Per

cyc

le a

nd

co

lum

n, v

alu

es f

ollo

wed

by

the

sam

e le

tter

are

no

t si

gn

ifica

nt

diff

eren

t w

ith

an

α=0

.05.

61


Film Performance

The mechanical behaviour of mulches were evaluated visually by taking photos along the crop cycle. These films showed an adequate resistance until near the end of the crop cycles and did not compromise the plants development. The film that showed the best performance especially in yield – ABF11 – also had the most interesting performance on the field. By the time that all the leaf area was fully grown (about 3 months after plantation) and the first harvest was completed (unripe fruits) the films had an adequate physical degradation that would allow mechanical harvest to ripe fruits and further biodegradation in soil. Unfortunately, this operation could not be performed because of the early rainfall that made it impossible to get the machines in the field.

Figure 4.10 – August 1st 2012: ABF11 (left) showing plants full developed and the mulch with degradation that would allow the mechanical harvest; ABF6 (right) showing plants full developed and the mulch without degradation.

1.4.Conclusions for short cycle crops – Portugal

From the data collected during the project, namely air temperature, relative humidity, solar radiation and rainfall it was possible to conclude that the years analysed were normal and the results obtained are valid to the climatic conditions of the region.

All the parameters analysed in soil monitoring did not show any difference caused by the biodegradation of Agrobiofilm® during the monitoring period.

62 Agrobiofilm®

In the muskmelon case WVC of ABF1 was around 3.3 % higher than in polyethylene (PE1) in the first cycle and around 5.1 % more than the PE 1 in the second cycle. ABF3 had also higher WVC than PE1.

The average muskmelon production in Portugal is around 25t/ha (OMAIAA, 2012). In the first year the production obtained was much higher (ABF1 with 32.62 t/h) than the average and in the second cycle despite lower values it was within the acceptable range for this region. Combining all the results from soil monitoring, crop yield, pests and diseases and mulch performance in muskmelon the Agrobiofilm® with the best results was ABF1 which is recom-mended for this crop and for these edaphic-climatic conditions or similar ones.

The best results obtained in bell pepper production were ABF11 and ABF7 with 82.9 and 79.6t/ha respectively.

In terms of quality parameters we concluded that in general the best results were obtained with ABF 6 (also in pulp thickness of great importance to industry) and ABF8.

The ABF11 had the most interesting performance on field since by the time that all leaf area was fully grown (about 3 months after plantation) and the first harvest was already done (unripe fruits) the films had an adequate physical degradation to allow mechanical harvest to ripe fruits and a further better biodegradation in soil. It is interesting to point out that this mulch (the thinner one) had a very good performance and it can be economically very promising.

Finally for bell pepper production we recommend that the Agrobiofilm® choice should be carried out according to the objective. Whether the product is for fresh consumption or for the processing industry and whether the harvest is made mechanically. The range of Agrobiofilm® tested in bell peppers allowed us to identify which mulch is more appropriate for each of these objectives.

63

2. Long Cycle Crops - Strawberry

2.1. Introduction

Strawberry (Fragaria sp.) plant is an herbaceous perennial rosette highly adapted to diverse temperate climates and to production under forced artificial growing conditions. In mild winter climates, such as the Mediterranic regions, strawberries are a major small fruit crop of significant economic importance with increasing land use.

The ‘winter’ planting system developed in California is the most common production system for strawberry and is well adapted to Mediterranean areas such as the southern and south-western Portugal and southern Spain. With this system it is possible to achieve early and high quality production of strawberry fruit from January until June. On a smaller scale the ‘summer’ planting system for autumn and winter fruit production is used to extend the main crop season.

Strawberry planting system falls in the category of annual-hill system where strawberries are fruited once and renovated each season when

LONG CYCLE CROPS - STRAWBERRY

64 Agrobiofilm®

intensively managed under plasticulture. Growing day-neutral strawberries using plastic mulches has the same functionalities as the other cultures mentioned above, namely, protection for the soil disinfection activities, growth stimulation of young plants, soil temperature, decrease soil erosion, nutrient leaching, water evaporation (hence water saving) and weed control, mineralization increase (nitrates and sulphates), potential reduction of putrefaction, cleanliness and, therefore, the optimization of overall fruit quality.

Plants are generally grown on raised beds with drip irrigation and covered by conventional black (opaque) polyethylene plastic mulch, leaving the aisles between the beds able to be used for circulation (about 50 cm). High or low tunnels can be used to create an environment with higher air temperature extending the harvesting period, or to protect the crop from adverse weather conditions. It can also be performed in open field. Plastic mulch dimensions tend to range between 1.3 and 1.5 m wide (to cover the bed and anchor to the ground about 10cm on both sides) and a thickness of 30-40 microns, adequate to withstand breakage and degradation for the 8-10 months of campaigning.

Strawberry production systems in Portugal and Spain use black polyethylene but in other cropping systems the plastic mulches used can be transparent (Israel or California). Black film is preferable because weed control provided by the film, which is critical since there are no alternative methods for weed-ing excepted soil fumigation or manual removal. Grey mould, leaf and root diseases and nematodes are the most widespread diseases on strawberries under cultural conditions using black plastic. It is expected that biodegradable mulch films behave like PE mulch film on disease incidence and severity.


In the case of Strawberry tested in Portugal in the first cycle the variety used was “Honor” while in the second cycle was “Camarosa”. Mulching was performed mechanically, holes being made at same time (Figure 4.11). Plantation was done manually a few days after (figure 4.12).

65


In Spain, strawberry varieties used were: “Candonga”. In the first cycle mulching was also done by machine. However due to the experimental design (several different mulches in the same row) in the second and third cycle all mulches were laid by hand.

After making the beds and laying the mulch films soil disinfection is done through irrigation.

Figure 4.11 – Mechanical application of the Agrobiofilm mulch. The irrigation system is placed at same time and holes made by a cylinder device with knifes.

Figure 4.12 – Planting strawberries in Portuguese trials.

66 Agrobiofilm®

2.3. Crop Growing and Harvesting

2.3.1.Strawberry in PortugalSoil Monitoring (temperature and water volume content)

In both cycles, Agrobiofilm® mulches had a good performance in temperature and average WVC (table 4.8) and therefore the development of the strawberry roots was not compromised.

Table 4.8 - Average Soil Temperature and WVC – Strawberry trials

In the first cycle the WVC in ABF15 was higher both at 10 and 20cm depth. These are interesting results as most part of the roots are located in this depth range. This could have a great importance especially under the conditions of water scarcity typical of the European Mediterranean regions. In our opinion this occurs due to the higher permeability of these biodegradable mulches that seems to promote the entrance of water from rainfall and dew through the mulch surface (as showed before).

The permeability capacity of biodegradable mulch films may have other beneficial effects on the physical properties of the soil and should be further investigated. Unfortunately due to technical problems with the soil probes in the second cycle it was not possible to analyse all the months and for that the results showed are from December (2011), January, February and May (2012).

1 trialst

2 trialnd

Average Soil

Temperature and WVC

PE 3 ABF 15 ABF 16 ABF 17 ABF 18 NF 3

Temperature (°C)

WVC (%)

Temperature (°C)

WVC (%)

18.8

19.0

14.4

-

17.5

22.4

14.8

-

-

-

12.9

-

-

-

12.4

16.0

-

-

15.1

12.6

-

-

12.6

15.4

67


The soil from the field trials was loamy-sand soil (SRA, 1977) the physical and chemical characteristics were assessed before land preparation, film layout and after plowing Agrobiofilm® into the soil. All the parameters analysed did not show any differences caused by the Agrobiofilm® mulches biodegradation.

Pests and diseases

Weekly observations were performed to assess plant development, incidence and severity of pests and diseases.

Along the flowering cycles the population of thrips (Thysanoptera) was evaluated at least once a week. Soil and root samples were collected from each plot at the end of the crop cycle to be evaluated for fungi population and fungi diversity. Fungi were identified on the basis of their reproductive structures.

In the first cycle concerning pests, differences were only detected between production systems (Greenhouse and Open field being the total number of insects significantly lower in open field). No differences between mulch modalities within each system and no associated symptoms were observed in the fruits.

In the analysis made to soil mycobiota no differences were detected in any of the modalities or production systems. It was noted that in both production systems the PE3 had a tendency to show higher units forming colonies of fungus per gram of soil. The only relevant aspect that should be noted was the very low diversity of fungus. From the identification 29.9% were from the genus Cylindrocarpon, 18.2 % of Penicillium and 5.3% of Fusarium which are potentially pathogenic agents. However no associated symptoms on plants were detected.

68 Agrobiofilm®

In the second cycle in relation to pest and disease analysis no differences were detected between the different modalities. In this year the previous low diversity was again detected. The same genus were detected mostly Penicillium (59%), Cladosporium (7.7 %) and Fusarium (7.3 %) which are also potentially pathogenic agents but no associated symptoms in the fruits were seen. Unlike the previous cycle the Cylindrocarpon genus was not detected.

According to published research the reflected radiation of each mulch can make an effect on the migration of pest inducers of diseases (Summers & Stapleton, 2002; Csizinszkv et al., 1995). It was expected that the contamination would be different in each modality. However in both cycles no differences were detected. Also the different temperatures and WVC in soil under the Agrobiofilm® seems to have an influence on soil mycobiota. The biodegradable mulches had a general tendency to have lower number of fungi colonies.

Crop yield

In the first cycle the yield evaluation was made by harvesting the fruits of the 25 plants established in each of the three replications for modality.

In the greenhouses the results obtained were 31.6t/ha and 37.5t/ha on PE3 and ABF15 respectively. In open-field the yield was lower in relation to greenhouse with 27.6t/ha in PE3 and 24.7t/ha in ABF15 (Table 4.9). Both differences were not significant at a confidence level of 95%.

In the second cycle six modalities were tested, but only in open field. Despite of no statistic differences were registered between them it is important to emphasize that ABF15 had the highest productivity (23.6t/ha against 22.0t/ha) and the lowest % of non-marketable yield (Table 4.10).

69


Table 4.9 - Strawberry production in the first cycle with % of non-marketable fruits and market-able yield


Table 4.10 - Strawberry production in the second cycle with % of non-marketable fruits and mar-ketable yield


Modality

ABF 15

PE 3

ABF 15

PE 3

Non-marketable

fruits (%)

7.7

10.8

15.0

8.0

Marketable

Yield (t/ha)

24.7

27.6

37.5

31.6

a

a

b

b

1 Cyclest

Open field

Green-

-house

Modality

PE 3

ABF 15

ABF 16

ABF 17

ABF 18

NF 3

Non-marketable

fruits (%)

24.6

22.8

22.2

23.5

23.3

25.6

Average

Yield (t/ha)

22.0

23.6

19.3

20.2

17.4

19.2

a

a

a

a

a

a

2 Cyclend

On

ly o

pen

fiel

d

70 Agrobiofilm®

Fruit quality

The parameters tested in both cycles were phenols content, antioxidant activity, total soluble solids and acidity. During first trial no significant differences were observed (table 4.11).

Table 4.11 - Strawberry fruit quality analysis for the first cycle.

Per column, values followed by the same letter are not significantly different with an α=0.05.

Parameters tested during the second trial presented some differences with a tendency to better qualitative results of fruits cultivated under Agrobiofilm® mulches specially the total sugar content (table 4.12).

In Portugal and according to all monitored parameters (quantitative and qualitative) ABF15 had the best performance among all the modalities test-ed.

1 Cyclest

Modality Total Sugar(°Brix)

Acidity (g citric acid/

100g)

Antoxidant Capacity

(mMTrolox/100g)

Greenhouse

Open Field

PE 3

ABF 15

PE 3

ABF 15

7.0

6.8

7.4

7.5

a

a

a

a

a

a

a

a

a

a

a

a

2.88

2.69

2.46

2.34

2.16

2.17

2.16

2.16

71


Tab

le 4.12 - Straw

berry fru

it qu

ality analysis fo

r the seco

nd

cycle

Per co

lum

n, valu

es follo

wed

by th

e same letter are n

ot sig

nifi

cantly d

ifferen

t with

an α

=0

.05.

nd

PE

3

AB

F 15

AB

F 16

AB

F 17

AB

F 18

NF 3

Mo

dality

May 21

207.7

214.6

214.1

219.6

222.2

217.7

aababbbb

Jun

e 11

237.8

248

.5

232.8

241.7

214.9

252.0

bcdbbc

ad

May 21

856

.0

857.5

86

0.4

86

5.1

859

.3

851.3

abababbaba

Jun

e 11

876

.0

876

.0

878

.0

88

2.9

88

2.2

875.2

Jun

e 11

7.13

7.83

7.67

7.70

7.50

8.70

aaabbba

May 21

6.9

0

7.13

7.83

6.8

3

7.50

7.53

abdacc

adccdbe

May 21

0.77

0.8

9

0.8

5

0.8

1

0.9

0

0.8

1

adcbdb

Jun

e 11

0.9

7

0.9

9

0.6

9

0.9

2

0.9

4

1.05

cddabbc

e

An

tioxid

ant activity

(mo

l Tro

lox/10

0g)

To

tal Sug

ar (° B

rix)P

hen

olic

(mg

CA

E/10

0g)

Acid

ity( g

citric acid/10

0g)

2 Cycle - w

ith d

ifferen

t dates o

f harvestin

g

thth

thth

thth

thth

72 Agrobiofilm®

Mulch films performance

The mechanical behaviour of the mulches was visually evaluated. In the winter of 2010/2011 during the first trial it rained above average and between the raised beds the soil was flooded for 4 months. This situation lead to a partial landslide on the raised beds adding more pressure to the mulch resistance but it did not compromise the films mechanical characteristics until the end of the cycle.

The overall performance in both cycles of tested mulches showed an adequate resistance not compromising crop development.

2.3.2.Strawberry in Spain Soil Monitoring (temperature and water volume content)

In Spain the field trials were made in a sandy soil. The physical and chemical characteristics were assessed before the land preparation, film layout and several times after the Agrobiofilm® being ploughed into the soil. All parameters analysed did not show any difference caused by the Agrobiofilm® biodegradation.

73

Table 4.13 - Soil Average Temperature (°C) and Soil Average Humidity (%) in Strawberry trials in Spain


21

21

28

27

24

19

-

-

-

-

16

23

13

19

17

19

15

15

17.7

18.4

16.9

17.2

17.7

15.0

18.1

17.7

18.4

18.2

16.4

17.8

16.6

12.3

16.5

16.2

15.5

17.2

22

22

29

28

24

23

-

-

-

-

16

18

18

19

16

18

17

18

17

23

27

30

17

22

-

-

-

-

10

20

15

20

17

18

21

17

Strawberry

Spain

Modality

ADESVA

ADESVA

ADESVA

GARRIDOMORA

Soil Average

Temp. (°C)

Soil Average

Humidity (%) at 3 depths

nd

rd

1 Cycle st

2 Cycle

3 Cycle

10 cm 20 cm 30 cm

ABF 19

PE 4

ABF 19

PE 4

ABF 20

ABF 24

ABF 25

ABF 26

ABF 28

NF 4

NF 5

PE 4

ABF 27

ABF 29

ABF 30

ABF 31

ABF 32

PE 4

74 Agrobiofilm®

In all the trials different temperatures and soil WVC were recorded. The biodegradable mulches were grouped into three categories: 1) films that reflected less moisture content (WVC), 2) equal and 3) greater than PE4. Apparently different moisture content in soil did not influence the yield in a clear way. In relation to soil temperature in some cases such as ABF27 and ABF28 the biodegradable mulches seem to have an positive effect on yield. With these mulches recorded temperatures were equal or greater than PE4 respectively, being the yields also higher than other modalities, but no different to the results registered for PE4. In the same way, ABF24 obtained lower temperatures had also a lower yield. However, this ratio was not confirmed with other Agrobiofilm® mulches. For instance ABF29 registered 4°C less in relation to others films but production was similar to PE4, ABF30, ABF31 and ABF32 (Table 4.13 and figures 4.13, 4.14 and 4.15).

75


Figure 4.13 - Soil average humidity of 3 depths (10, 20 and 30cm) and soil temperature in ADESVA and Garrido Mora field tests – 1st cycle.

18

20

22

24

26

28

30

32

Nov Dec Jan Feb Mar Apr May

Hu

mid

ity

(%) PE 4 - ADESVA

ABF 19 - ADESVA

PE 4 - GMora

ABF 19 - GMora

13

15

17

19

21

23

25


Tem

per

atu

re (°

C)

PE 4 - ADESVA

ABF 19 - ADESVA

PE 4 - GMora

ABF 19 - GMora

76 Agrobiofilm®

Figure 4.14 - Soil average humidity of 3 depths (10, 20, 30cm) and soil temperature (15cm depth) in ADESVA and Garrido Mora field tests – 2nd cycle.

10

12

14

16

18

20

22

24


Hu

mid

ity

(%)

PE 4 NF 5

ABF 20 ABF 24

12

14

16

18

20

22

24


Tem

per

atu

re (°

C)

ABF 24 NF 5

PE 4 ABF 28

ABF 20 ABF 25

77

Figure 4.15 - Soil average humidity of 3 depths (10, 20, 30cm) and soil temperature (15cm depth) in ADESVA field tests – 3rd cycle.


12

14

16

18

20


Hu

mid

ity

(%)

PE 4 ABF 27

ABF 30 ABF 31

12

14

16

18

20

22


Tem

per

atu

re (°

C)

PE 4 ABF 27 ABF 30 ABF 31

78 Agrobiofilm®

Pests and diseases

In ADESVA and Garrido Mora (first cycle) a weekly monitoring of pest and diseases was made, sampling 10 plants per greenhouse, randomly, observing a flower and a leaf per plant. Along the trials there was a significant fluctuation of population count of all the pests. This justified insecticide application.

Over the second and third cycle, there were two sampling areas of pests and diseases. One in the greenhouses where all biodegradable mulches were and the other one in the rest of the experimental field where only polyethylene mulch was located. As all biodegradable modalities were randomly distributed in the greenhouses a single sampling was done for Agrobiofilm® and compared with PE. In the first cycle more pests in PE modality were observed but there were no significant differences in diseases incidence.

Table 4.14 - 1st Trial - Average number of thrips (Frankliniella occidentalis), Tetranychus urticae and Aphids

In the second cycle both ABF27 and ABF28 recorded less presence of diseases and less incidence of pests when compared to PE.

GARRIDO

MORA

ADESVAPE 4

ABF 19

PE 4

ABF 19

5.5

3.4

3.0

2.8

4.2

0.6

3.3

3.2

1 Trial Strawberry

st

Thrips/flower

Tetranychus/leaf

Aphid/

leaf

5.7

3.6

43.1

10.0

79


Table 4.15 - 2nd Trial - Average number of thrips (Frankliniella occidentalis), Tetranychus urticae and Aphids

In the third cycle Agrobiofilm® results were consistent with the second cycle albeit PE results outperformed its own results from the second trial.

Table 4.16 - 3rd Trial - Average number of thrips (Frankliniella occidentalis), Tetranychus urticae and Aphids

ADESVAPE 4

Average of 11

Agrobiofilm

29.2

23.9

1.6

0.0

2 Trial Strawberrynd

Thrips/Flower

Tetranychus/leaf

Aphid/

leaf

14.07.0

ADESVAPE 4

Average of 11

Agrobiofilm

4.7

4.6

1.5

2.4

3 Trial Strawberryrd

Thrips/Flower

Tetranychus/leaf

Aphid/leaf

3.4

3.9

80 Agrobiofilm®

Crop yield

In the first cycle PE provided higher values of early production (considered until 31 March) in ADESVA and Garrido Mora. Total production was not significantly different in ADESVA but was higher in PE modality at Garrido Mora field. Plants were also more vigorous in PE modalities both at ADESVA and Garrido Mora (Table 4.17). As a consequence new biodegradables mulches were produced and tested in the second cycle.

Table 4.17 – Strawberry production on ADESVA and “Garrido Mora” for the first cycle of trials in Spain

Per field trial and column values followed by the same letter are not significant different with

an α=0.05.

For the second cycle there was a group of Agrobiofilm® that had lower productivity than PE. However there was another group of Agrobiofilms that had similar or even better behaviour than PE4 (AFB20, ABF22, ABF23, ABF25, ABF27 and ABF28). Among these must be highlighted ABF28 which had a significant higher early production and ABF20 which presented the highest production (table 4.18). Regarding plant vigour, in the second cycle this parameter was statistically different to PE just in three biodegradable mulches: ABF24, ABF25 and ABF26 (lower values than PE4 in the first two and higher in the ABF26).

ADESVA

GARRIDO

MORA

Field

Trial

Modality Early

production

(t/ha)

1st

category

(t/ha)

2nd

category

(t/ha)

Total

(t/ha)Vigor

(cm)

PE 4

ABF 19

PE 4

ABF 19

16.70

12.22

18.73

12.10

49.15

46.34

37.30

27.13

5.89

5.38

7.73

6.55

55.04

51.71

45.02

33.68

22.70

20.24

23.95

19.88

a

b

a

a

a

a

a

b

a

a

a

a

a

a

a

b

a

b

a

b

81


Tab

le 4.18

- Strawb

erry pro

du

ction

on

AD

ESV

A an

d “G

arrido

Mo

ra” for th

e secon

d cycle o

f trials in Sp

ain

Per trial valu

es follo

wed

by th

e same letter are n

ot sig

nifi

cant d

ifferen

t with

an α

=0

.05.

Mo

dality

Early

pro

du

ction

(t/h

a)

1 st categ

ory

(t/ha)

2 nd

categ

ory

(t/ha)

To

tal p

rod

uctio

n(t/h

a)

Fruit

weig

ht

(g/fru

it)

Vig

or

(cm)

2nd

categ

ory

(%)

AB

F 20

AB

F 21

AB

F 22

AB

F 23

AB

F 24

AB

F 25

AB

F 26

AB

F 27

AB

F 28

NF 4

NF 5

PE

4

24.58

17.15

20.6

6

22.16

18.56

21.00

17.54

22.07

26.16

17.25

19.4

9

20.20

70.22

54.30

66

.66

67.9

9

58.0

7

68

.59

61.0

2

64

.79

67.8

3

60

.24

63.8

9

69

.08

abcabc

abc

cabc

cabc

acbc

bc

aeabc

abc

de

abc

bcd

e

abcd

acde

abcd

ab

11.71

8.9

5

8.6

6

10.17

9.0

0

9.26

6.76

10.8

4

10.17

5.66

7.26

9.8

2

abaababaabaa

81.9

3

63.26

75.32

78.16

67.0

7

77.85

67.78

75.62

77.93

65.9

1

71.16

78.9

0

abcd

bcd

abbcd

bc

de

ababecde

ab

25.5

25.1

25.7

26.2

24.6

26.6

25.3

25.9

26.4

24.6

24.6

22.8

28.2

26.4

27.9

27.0

27.2

32.0

25.9

27.1

27.1

26.9

27.9

27.8

14141113131210141391012

aaaaaaaaaaaa

82 Agrobiofilm®

Tab

le 4

.19

- 3

rd C

ycle

Str

awb

erry

pro

du

ctio

n o

n A

DE

SVA

, Sp

ain

Val

ues

fo

llow

ed b

y th

e sa

me

lett

er a

re n

ot

sig

nifi

can

t d

iffer

ent

wit

h a

n α=

0.0

5.

Mo

dal

ity

Ear

ly(t

/ha)

1 st

ca

teg

ory

(t/h

a)

2 n

d

cate

go

ry(t

/ha)

To

tal

pro

du

ctio

n(t

/ha)

Fru

it a

vera

ge

wei

gh

t (g

/fru

it)

Vig

or

(cm

)2n

d

cate

go

ry

(%)

AB

F 27

AB

F 28

AB

F 29

AB

F 30

AB

F 31

AB

F 32

AB

F 33

AB

F 34

AB

F 35

AB

F 36

NF

5

PE

4

15.0

3

13.9

3

14.7

7

14.2

3

14.0

1

17.4

7

17.7

6

15.8

7

14.0

2

18.9

0

17.1

2

17.6

3

55.0

8

52.9

2

50.3

3

49

.15

46

.27

51.5

9

54.3

4

52.6

1

49

.27

55.0

7

53.2

9

53.7

3

a a a a a a a a a a a a

a ab ab ab b ab a ab ab a ab a

10.4

9

7.9

1

8.3

8

8.2

1

11.7

3

9.6

5

9.6

6

10.5

3

8.4

8

10.5

2

8.5

8

9.3

1

a abcd

bcd

cd d abcd

ab abc

cd a abcd

abc

65.

55

60

.83

58.7

1

57.3

6

56.5

1

61.

24

64

.01

63.

15

57.7

5

65.

32

61.

88

63.

04


28.8

2

26.7

8

25.6

3

25.9

9

26.5

0

25.2

5

28.3

7

26.1

8

27.9

9

26.2

5

27.4

1

26.5

0

24.7

24.4

23.9

23.8

23.6

24.9

25.3

25.5

23.9

24.4

25.5

25.7

16 13 14 14 21 16 15 17 15 16 14 15


83

In the third cycle (ADESVA) all Agrobiofilm® mulches achieved similar early/ production without significant differences to PE4. Regarding total production 9 out of 10 Agrobiofilm® mulches presented values with no differences to PE4.Again it must be highlight a trend to higher production in Agrobiofilm® mulches: ABF27 = 65,55t/ha; ABF33 = 64,01t/ha; ABF34 = 63,15t/ha; ABF36 = 65,32t/ha; PE4 = 63,04t/ha.Regarding plant vigour in the third cycle there were no differences between any of the 12 mulching modalities.

Fruit quality

In quality evaluation two parameters were followed firmness of the fruits and total soluble solids (°Brix). Regarding firmness there were no statistically differences in the first and third cycles. However in the second cycle there were two biodegradable mulches ABF27 and ABF28 with significantly higher values than PE4.

Regarding total sugar content of fruits all the 17 Agrobiofilm® mulches tested during the second and third cycles presented values with no significance differences to PE4.


84 Agrobiofilm®

Table 4.20 – Strawberry quality monitoring on ADESVA and “Garrido Mora” experimental fields.

Per cycle and column values followed by the same letter are not significant different with an

α=0.05

Cycle/Fieldtest

Modality TotalSugar(° Brix)

Firmness (g/cm )2

ADESVA

ADESVA

ADESVA

GARRIDO MORA1

Cyc

lest

2 C

ycle

nd

10.199.51

10.1610.35

9.19.49.09.58.79.38.18.07.78.18.17.79.39.69.19.39.39.69.49.49.09.39.19.6

664.27683.05643.48702.43429.3436.9438.7430.9420.8448.1464.2463.9448.5440.1453.5434.5397405409431420420397422421393413419

a

b

a’

b’

ab

a

abc

a

abcd

a

bcd

cd

d

bcd

bcd

d

ab

ab

ab

ab

b

ab

a

a

ab

ab

ab

ab

a

a

a

a

a

a

a

a

a

a

a

a

a

a

a

a

a

a

a

a

a

a

a

a

a

a

a’

a’

3 C

ycle

rdPE 4

ABF 19PE 4

ABF 19ABF 21ABF 19

NF 5ABF 26

PE 4NF 4

ABF 27ABF 28ABF 20ABF 23ABF 22ABF 25ABF 27ABF 28ABF 29ABF 30ABF 31ABf 32ABF 33ABF 34ABF 35ABF 36

NF 5PE 4

85


Film Performance

In general biodegradable mulches were in good conditions until beginning of May with different scales of degradation. Throughout the three cycles visual observation was made weekly and resistance to breaking and film biodegradation was evaluated. In the first and second cycle biodegradable mulching showed good behaviour in relation to resistance to breaking or cracking along the whole season. Only ABF26 started to biodegrade at the base of the bed in early March. The rest of the films had the same behaviour near the end of the season but this did not affect the crop which presented a normal development.

In the third cycle the films that presented more degradation at base of the bed were ABF30 and ABF35 followed by ABF33 and ABF36. In relation to this fact ABF28 registered the best behavior followed by ABF27 and ABF31. In general the crop was not affected and mulches with additives seemed to present lower degradation. The film with worst mechanic resistance (cracks and breaks in both sides and at the top of the bed) was NF5 followed by ABF33, ABF34 and ABF36. In general the rest of the mulches showed good behavior highlighting ABF28 and ABF29.

Another visual indication of biodegradation was the presence of pores at the top of the bed. This could be observed only in the mulch ABF30 (beginning of December 2012) and ABF34 (beginning of February, 2013). In both cases the damage was not prominently developed and did not cause any decrease in fruit production.

86 Agrobiofilm®

2.4. Conclusions

All the soil monitoring parameters analysed did not show any difference caused by the Agrobiofilms biodegradation during the monitoring period.

PortugalIn both cycles Agrobiofilm® had a good performance both in soil temperature and average WVC and the development of the strawberry plants was not compromised. Furthermore, in the first cycle the WVC was higher at 10 and 20cm depth compared to PE3, which can be considered of a great importance especially under the conditions of water scarcity, typical of the European Mediterranean regions.

In relation to pest analysis ABF18 showed a higher tendency to have more beneficial insects registering an interesting population level of thrips predator Aeolothrips tenuicornis.

It is important to emphasize that ABF15 had higher productivity in open field and had always the lowest % of non-marketable fruits. The overall performance of the tested mulches in both cycles showed an adequate resistance during the crop cycle and did not compromise plant development.

In Portugal especially in open field and according to all the monitored parameters ABF15 had the best performance among all the modalities tested and it would be the mulch selected for this crop under these edaphic-climatic conditions or in similar ones.

Spain A visual indication of biodegradation was the presence of pores at the top the bed. This could be only observed in ABF30 (beginning of December 2012) and ABF34 (beginning of February, 2013). In both cases the film damage was not prominently developed and did not cause any decrease in production.

For greenhouses, considering all the monitored parameters and tried films, we can propose a range of Agrobiofilm® mulches film that can be best suitable to the Andaluzia edaphic-climatic conditions: ABF20, ABF23, ABF27 and ABF28, being ABF23 and ABF28 more adapted to soils with higher content of sand.

87


3. Perennial Crops - Vines

3.1. Introduction

The successful establishment of a new vineyard depends strongly on the first growing years and usually start to produce grapevines during the third season. The use of polyethylene (PE) mulch films in the vine row is sometimes used in newly planted vineyards not only for a herbicidal effect and to ensure their successful and homogeneous establishment but also to deliver earlier production. Indeed mulched vines may produce a crop one year earlier than un-mulched vines (Godden and Hardie 1981; Moore 1963; Pinamonti 1998; Van der Westhuizen 1980). Such films lead to a better preservation of soil moisture, more uniform soil temperatures, less leaching of fertilizers, lower soil compaction, weed control, an increased growth and a higher survival rate (Van der Westhuizen 1980). Furthermore, an increase in vegetative growth and yield were observed up to three years after planting when the film was removed after the first season (Moore 1963) and up to five years after planting when it was maintained 18 months (Van der Westhuizen 1980).

88 Agrobiofilm®

However despite the described benefits, the use of mulch films are not widely used by most European winegrowers. Among the cited reasons, one is that it is not easily removed from vineyards, a clear disadvantage of PE films leading to significant waste disposal issues often resulting in environmental pollution (figure 4.16).

Indeed there is a discrepancy between the long-term stability of PE and the material lifespan required in mulch applications. In the case of long-term perennial crops such as grapevines the mulch lifetime needs to be further studied considering that the reported effects mainly focus on the early crop cycles. In this context the performances of biodegradable mulch films which constitute an environmentally friendly alternative to the currently used polyethylene film have to be assessed in vineyard field experiments.

Figure 4.16 – Polyethylene mulch film in Languedoc-Roussillon region Vineyard. This mulch is breaking in pieces (B), has no longer herbicide effect and is being incorporated in the soil (A). The aesthetic degradation of the landscape is remarkable. Carcassone, France, April 2010.

A B

89

PERENNIAL CROPS - VINES

Minuto et al. (2008) reported a preliminary study on the use of Mater-Bi-based mulch films in vineyards. According to the authors film thickness and formulation are key parameters for the efficiency of the film. They report a reduction of weeds growth over a 12 month period improved vine establishment with mulching vineyards compared to an un-mulched treatment. Despite the low number of available studies on the use of biodegradable mulch films in vineyards there is a strong need for further research activities on the topic. In our study the effects of a biodegradable mulch film have been tested on soil and viticulture parameters in comparison with conventional PE film and bare soil in a Chardonnay vineyard in a Mediterranean climate.


All mulch films were laid down by machine over the vines in the row. As the machine progressed, it covers the edges of the films with soil (about 15 cm each side), resulting in an 80cm wide film strip covering the soil surface (figure 4.17).

Figure 4.17 – Tractor with implement to laid down mulch film in vines (A). Mulching vines is always after planting (B). Blomac, France, April 2010.

A B

90 Agrobiofilm®

The mulch width is related to the inter-row distance. For a 3.0m inter-row a 110cm mulch can be used as remain 2.0m of un-mulched and which is considered enough space for tractor operations in the inter-row. However for lower inter-row distances (for example: 2.0 - 2.5m) the mulch width can be reduced to 90cm (presenting a 60cm wide film strip). This Agrobiofilm® width was already used in Portugal in Dão and Vinho Verde regions during the 2013 plantations for inter-row distances of 2.2m and 2.0m (Figure 4.18). A major advantage is also the possibility to install the drip irrigation system together with the mulch film. The drip irrigation is placed under the mulch film (figure 4.18 B), as irrigation tape in horticultural crops.

Figure 4.18 – Tractor with implement to laid down mulch film in vines. Mulching vines is always after planting. Inter-row distance of 2.0m (A) and 2.2m (A) and mulch width 90cm. Portugal, Dão region May 2013 (A) and Vinhos Verdes region, June 2013 (B).

A B

91


Films were then slit by hand above each vine, stabilized with some soil at the base of each plant thus improving the small scale green-house effect under the mulch film (Figures 4.18A and 4.19).

Figure 4.19 – Some soil is placed at the base of each vine, in PE mulch (A) and Agrobiofilm® (B). Blomac, France, April 2010.

The Chardonnay cultivars grafted on SO4 rootstocks were planted on April 1st of 2010 with 0.8m within rows, oriented E/W, and 3.0m between rows (4166 vines per hectare).

Different treatments were applied about two weeks after vine planting. The experimental area allocated to this trial was 0.3ha. This experiment was established using a complete randomized block design with three replicates. Each repetition being approximately 17m long per line and corresponding to 23 vines per line - with a total of 5 lines (Figure 4.20).

A B

92 Agrobiofilm®

Figure 4.20 – Experimental design of trial 1, Blomac, France, April 2010. PE= Polyethylene mulch; ABF = Agrobiofilm® mulch; BS= Bare soil.

3.3. Mulch Impact on Soil Characteristics

The trial was implemented on a calcareous soil whose main physical and chemical properties are presented in table 4.21. The initial chemical properties are representative of a vineyard soil in this region (table 4.21).

Since the effect of soil management on such characteristics might partially explain the mulch-induced effect on viticulture parameters, soil analyses were undertaken to better evaluate the impact of mulching on physical, chemical and biological soil characteristics. However because the chemical properties of soil are characterised by great inertia, it is not expected to significantly change in a short time scale. As a consequence only the most relevant mulching-induced changes observed two years after vine planting are presented below (Tables 4.22 and 4.23). Amongst them the soil microbial biomass content is an indicator of its biodegradation ability which can be considered as a key parameter ensuring the ultimate bio-assimilation of the Agrobiofilm® mulch by the soil.

buffer line

buffer line

BLOCK1 BLOCK2 BLOCK3

223 m

PE PE PEABF ABF ABFBS BS BS

Repetition 1

Repetition 2

Repetition 3

93


Table 4.21- Physical and chemical properties of the soil at planting time (t0)

Regarding the bulk density (Table 4.22) a parameter for which the mulching treatment might have an impact no significant change was observed suggesting that the texture of the soil was not influenced by the presence of mulch film during the two first years following vine planting. In contrast the soil organic matter content and its C/N ratio slightly increased with time especially for both mulching treatments (ABF and PE) as compared to bare soil. Given that the same amount of fertiliser was applied whatever the treatment considered these changes may be attributed to a higher biological ac-tivity in mulched soils. This could be due to higher water retention in the mulched modalities especially in the case of PE film whose water vapour permeability is 10 fold lower than those of ABF.

Parameter Method Value

Physical properties

Apparent density (g/cm ) 3 Cylinder method 1.46 (± 0.07)

19/42/39NF ISO 11464Texture: clay/silt/san (%)

Chemical properties

pH - H O2

CEC (Cmol+/kg) (Metson)

Total CaCO (g/kg)3

Active CaCO (g/kg)3

Phosphorous (g/kg) (Olsen)

Conductivity (mS/cm)

NF ISO 10390

NF X 31-130

NF ISO 10693

NF X 31-106

NF ISO 11263

Inra Method

8.46 (± 0.02)

7.19 (± 0.06)

182 (± 5)

35.3 (± 4.0)

<0.005

0.0820 (± 0.0004)

94 Agrobiofilm®

Table 4.22 - Evolution of soil physical, chemical and biological parameters for mulched treatments (PE and ABF) and bare soil (BS)

Values with different subscript are considered as significantly different at α=0.05

The values of the biological parameters of the soil, i.e. the microbial biomass and the nematode abundance at planting time (t0) reveal a rather low biological soil activity (Tables 4.22 and 4.23). Despite the existence of a spatial heterogeneity the fact that all soil samples contained very few microbial biomass and nematodes is namely an indicator of an unbalanced soil, which is also poor in nutrients as typically observed in the location of the present experimental field. However the microbial biomass significantly increased (+220%) two years after vine planting for all treatments. This parameter gives an indication of biodegradation potential in soil and its evolution can be considered positive since it’s expected to favour the bio-assimilation of the Agrobiofilm® mulch film by the soil.

Regarding the nematofauna, two years after planting it can be noted that the abundance of total nematodes increased in all treatments and this rise was notably higher in the case of ABF treatment due largely to an increase in the plant-feeding nematode group (Table 4.23) mainly Tylenchidae and Pratylenchidae both known to be harmless to vines. These results suggest a more diversified soil biological activity with the ABF treatment possibly the result of the progressive decomposition of ABF film leading to soil enrichment with carbon components potentially available to the nematodes.

Bulk density(g/cm )

Time(months )

Organic matter(g/kg)

Microbial biomass(mgC/kg)3

C/N

tt

0

24 BSBS

PEABF

1.461.39

1.381.42

10.3811.90

12.3012.90

11.9714.07

14.9016.00

55.2171.0

175.7171.6

± 9.3

± 7.2

± 28.4

± 32.4

± 0.60

± 1.46

± 0.28

± 1.40

± 0.49

± 0.89

± 0.99

± 1.32

± 0.05

± 0.06

± 0.03

± 0.07

a

a

a

a

a

ab

ab

b

a

ab

b

b

95


Tab

le 4.23- E

volu

tion

of th

e abu

nd

ance o

f the n

emato

de tro

ph

ic gro

up

s as related to

the m

ulch

ing

treatmen

t app

lied (P

E an

d A

BF)

in co

mp

arison

with

bare so

il (BS) exp

ressed in

ind

ividu

al/100

g d

ry soil

Valu

es with

diff

erent su

bscrip

t are con

sidered

as sign

ifican

tly diff

erent at α

=0

.05.

Bacterial-feed

ersFu

ng

al-feed

ersO

mn

ivores

and

carnivo

res

Plan

t-feed

ing

Free-living

nem

atod

esT

otal

nem

atod

es

t0

t12

t24

BS

BS

BS

PE

PE

AB

F

AB

F

110a

151

159117

191

aaa

a

189

a

131a

±26

±34

±17

±4

9

±4

6±

52

±6

0

56a

19a

180

a

105

a

236aa

152

244

338

538

a

2620

aa

155121

±3

±1

±6

aaa bb

75a

91

52

aa

121 a

93

a

130a ±

9±

3

±10

±7±1

±24

±18

±4

±17

±29

±36

±4

0

±23

±32

±6

1

±35

±34

±14

1

bab

186

a

251a

299

a

198

a

285

211

342

aaa

±34

±4

8

±20

±52

±6

3

±8

2

±79

385

356536

350

530

549

879

aababaabb

±6

8

±6

5

±51

±9

9

±9

8±

115

±9

8

Tim

e(m

on

ths)

96 Agrobiofilm®

3.4. Ageing of Agrobiofilm Under Field Conditions The biodegradable mulch film was laid down in April 2010 and started revealing some cuts by mid-August 2010, i.e 4 months after the vine planting (Figure 4.21).

Figure 4.21- First signs of deterioration of the Agrobiofilm® mulch film (ABF) 4 months after installation: (A): 30 July 2010: the film is still intact. (B): 16 August 2010: cuts appear on the film.

In April 2011, i.e. one year after the start of the field experiment the biodegradable mulch film did not cover all the soil anymore whereas the polyethylene mulch film was still intact (Figure 4.22). As a consequence of the early breakage of the ABF mulch film, weed needed to be controlled from the beginning of the second growing season, not only in the inter-raw but also in the raw by applying an herbicidal treatment. However, at this stage of the vine development, the vine growth and lignification were sufficient to enable the herbicidal treatment to be applied with the tractor, requiring no extra man work. Additionally this lignification allows the utilisation of a systemic herbicide which can usually only be used in vines with more than 3 years. This represents a significant cost reduction as the alternative (contact herbicide) can be 3 times more expensive.

BA

97


Figure 4.22- Aspect of Agrobiofilm® (ABF) and (PE) mulch films after 12 months spent under field conditions.

Figure 4.23 - Aspect of Agrobiofilm® (ABF) and (PE) mulch films after 26 months spent under field conditions.

ABF PE

ABF PE

98 Agrobiofilm®

In June 2012, i.e. more than two years after planting (Figure 4.23) the biodegradable mulch film appeared again more deteriorated in comparison with the PE mulch film which was still intact. However the ABF mulch film appeared partially covered by the soil probably due do the watering of the soil by spring rainfalls. This event could be considered advantageous for its further expected biodegradation at the soil surface without the subsequent burying step.

To speed up the biodegradation of Agrobiofilm® mulch in soil, the vine row can be worked between vines, ploughing and or covering mulch with soil. Figures 4.24 and 4.25 represent two optional implements.

Figure 4.24- Traditional vineyard plough (http://www.abolsamia.pt/usado.php?ad_id=17321).

Figure 4.25- A sensitive vineyard plough or rotary intervine tool (http://www.boisselet.fr/en/p-30/starmatic.html).

99


3.5. Vegetative Growth

At the end of the first growing season vines in the mulched treatments had similar grow rate and vigour, while the vines grown on BS were weak and exhibited variable growth (figure 4.26) as previously reported by Moore (1963) and Van der Westhuizen (1980).

Figure 4.26 - Vegetative grow observed in September 2010 (5 months after planting). (A)=PE; (B)=ABF; (C)=BS.

These visual observations were quantified by means of shoot length measurements at the beginning of the winter dormancy. The results showed that grapevine growth was significantly higher (3.3 times more) for both mulched treatments (PE and ABF) than for the un-mulched one (BS) (Figure 4.27). In contrast the two mulch films (PE and ABF) were not found to be significantly different in terms of grapevine growth.

A

B

C

100 Agrobiofilm®

Figure 4.27 - Effect of mulching on total shoot length. Different letters represent a significant difference between treatments at a 95% confidence level (Tukey test).

In order to assess the impact of mulching on vine growth, during the second growing season, the phenological stages of the grapevine were recorded according to time following the BBCH scale (Lorenz et al,. 1994). At the same dates and for 10 representative plants randomly taken in both PE and ABF modalities the length of the next to last shoot of the selected grapevines was measured (Figure 4.28). No difference in the early development of phenological stages was noticed between the PE and ABF mulched vines. Similarly the effect of the nature of the mulching film on the shoot lengths was not statistically significant (Figure 4.28).

To

tal s

ho

ot

len

gth

by

vin

e (c

m)

1200

1000

800

600

400

200

0

208

689698

a b b

BS PE BF

101


Figure 4.28 - Shoot length measurements in the PE and ABF mulch film during the second growing season. Numbers located at the top of the graphic correspond to the phenological stages of the grapevine at the time of the measurement: 53- Inflorescences clearly visible; 55- Inflorescences swelling, flowers closely pressed together; 57- Inflorescences fully developed, flowers separating; 65- Full flowering, 50% of flowerhoods fallen; 77- Berries beginning to touch; 79- Majority of berries touching; 85- Softening of berries (BBCH scale. Lorenz et al., 1994).

3.6. Production and Berry Quality Parameters

Remembering that vines were planted in April 2010, the next table shows the production values of the two first harvests. Vines grown under PE and Agrobiofilm® produced significant quantities of grapes 17 months after planting while it was necessary to wait for an extra year in the case of BS treatment. The values per vine shown in the table 4.24 represents a first harvest yield of 17.8t/ha and 21.2t/ha respectively for Agrobiofilm® and PE treatments. Although yield differences were not significantly different

Sho

ot

len

gth

(cm

)

140

120

100

80

60

40

20

0

53 55 57 65 77 79 85

Date

4 - 7 -1

1

4 - 27 -1

1

5 - 17

-11

6 - 6-1

1

6 - 26-1

1

7 - 16

-11

8 - 5-1

1

8 - 25-1

1

PE

ABF

102 Agrobiofilm®

between the mulching treatments in the 2011 harvest the ABF treatment produced must with higher soluble solids than the PE treatment (20.4°B and 18.5°B respectively) and had a lower pH (3.33 and 3.46 respectively). Both characteristics corresponding to a better must quality (table 4.24).

The results of the second harvest (2012) also indicated no significant difference in terms of fruiting yield and quality of the must between the ABF and PE treatments (Table 4.24). In contrast the BS treatment had a significantly higher yield than the two mulched treatments. The decrease in yield observed for the two-mulched treatments is probably due to their exceptionally high production yield in the first harvest. Nevertheless the total yield achieved in the mulched treatments during the two initial years after planting was remarkable in that it was more than 31t/ha. During the same period BS treatment obtained 20t/ha.

In the second harvest (2012) no differences were observed in the quality of the must parameters.

Table 4.24- Effect of mulching on production and must quality during the three initial growing seasons. Vineyard planted April 2010 first harvest August 2011 and second harvest September 2012

In each year values with different subscripts are considered as significantly different at α=0.05

Year/Treatment

Production (kg/vine)

Soluble solids(°Brix)

pH

2011

2012

BS

PE

ABF

BS

PE

ABF

0.39

5.06

4.24

a

b

b

4.34

3.34

3.06

a

b

b

± 0.03

± 0.87

± 1.23

± 1.57

± 1.49

± 1.35

18.5

20.4

a

b

21.5

21.6

22.0

a

a

a

- -± 1.5

± 0.6

± 0.1

± 1.6

± 1.5

3.46

3.33

a

a

a

a

b

3.30

3.44

3.42

- -

± 0.04

± 0.09

± 0.03

± 0.13

± 0.03

103


3.7. Vine Training and Pruning

The training system was installed in June 2010 and consists of two formation wires placed at 90cm and 120cm (Figure 4.29). In July and August the growth of some vines was sufficient to allow training. In these cases the longest shoot of the grapevine was wound with a vertical string tied to the wires. The apexes of the other shoots were cut to promote maximum development of the main shoot. The vines that would not allow training were let undisturbed. The first pruning was performed in March 2011. The severity of pruning for all treatments was based on the growth of each individual vine. In all cases only the best shoot was kept and all others were removed. Then concerning the smaller vines (those which did not reach the lower wire) the best shoot was shortened to two buds (Figure 4.29).

Figure 4.29 - Vine training and pruning system a) For the weakest vines main cane shortened to two buds b) for the most vigorous plants main cane bent over the upper wire and tied to the lower wire and c) for the vines with intermediate development main cane tied to the lower wire.

In the case of more developed vines if the main cane was long enough it bent over the top wire and then down the lower one where it was tied. For intermediate vines of which cane length did not permit bending over the upper wire the cane was shortened and tied to the lower wire. The number of buds left per cane depended on the length of cane that was kept (Figure 4.29).

120 cm

trelliswires

90 cm

a b c

104 Agrobiofilm®

The percentage of vines for which the growth was sufficient to be pruned with a cane has been evaluated for the totality of the vines of the field test. As a result 97% and 94% of the vines mulched with PE and ABF respectively had sufficient vigour to be pruned with a cane while only 13% of the un-mulched vines met this requirement (figure 4.30). In another point of view it is remarkable that the difference in vines shortened to two buds in the bare soil treatment 87% was pruned at two buds but this value was reduced to an insignificant 3% and 6% in the mulched vines.

Figure 4.30 - Effect of mulching on the percentage of grapevines able to be pruned with a cane at the end of the first growing season (March 2011).

0

20

40

60

80

100

13

97 94

BS PE BF

Vin

es p

run

ed w

ith

a c

ane

(%)

105


The second pruning was performed in March 2012 according to the single Guyot pruning system.

In all treatments ten vines per block have been selected for each modality and the pruning wood of each collected to be weighted. Results are presented in the next table.

Table 4.25 - Effect of mulching on pruning wood. Vineyard planted April 2010 the first pruning at March 2011 and the second pruning at March 2012

In each year values with different subscripts are considered as significantly different at α=0.05

The results of 2011 pruning confirmed the growth enhancement of mulched vines as pruning weight was 4.4 (PE) and 3.6 (ABF) times higher compared to the BS treatment (Table 4.25). At the end of the second growing season this mulch-improved vigour was still noticeable. The amount of pruning wood being almost twice as high for the ABF and PE treatments than for vines grown on bare soil (Table 4.25). Such results are consistent with the shoot length measurements made at the beginning of the second growing season (Figure 4.28)

Pruning weight differences between the PE and ABF treatments were not statistically significant for both years despite the early degradation of the ABF mulch film in the first growing season.

Year/

Treatment

Pruning wood

(g/vine)

2011

2012

BS

PE

ABF

BS

PE

ABF

23.1

102.3

83.9

a

b

b

225.7

427.6

411.5

a

b

b

± 17.2

± 73.0

± 64.2

± 144.3

± 136.5

± 206.1

106 Agrobiofilm®

3.8. Root Development

In vines the development of aerial part is deeply connected with root growth and a good and deep root system is a mandatory characteristic of a well establish vineyard. In order to understand the impact of mulching treatment on vine growth and confirm the positive effect observed on the aerial parts the development of the vine rootstock was monitored 25 months after planting. The study consisted in excavating and manually collecting the vine roots in the first 60cm soil horizon from a quarter of the Voronoï polygon (Figure 4.31).

Figure 4.31 – Description of the experimental design where the vine roots were sampled. Voronoi polygon is defined by half-distance between sampled vine and neighbours in the row.

40 cm

40 cmsquare

2

square

1

Voronoi polygon defined by half-distancebetween sampled vine and neighbours

raw

inter-plant distance = 80 cmvine plant

raw

inte

r-ro

w d

ista

nce

= 3

00

cm

107


Their morphological parameters (length and diameter) were then characterised and their dry weight determined (Table 4.26).

Table 4.26- Root growth of mulched (PE and ABF) or un-mulched (BS) 2 years-old vines. Results are expressed as cumulated dry weight (g) and cumulated root length (cm) for a total soil volume of 96 dm3 sampled in the first 60cm thick soil horizon

Values with different subscripts are considered as significantly different at α=0.05

As evidenced by the total dry weight of roots developed between the soil surface and 60 cm depth in the two squares studied (Table 4.26) vines grown with Agrobiofilm® treatment developed significantly more roots (about twice more) than with the two other treatments whatever the depth and the square considered (Figure 4.32). This behaviour is also confirmed by the total root length measurements that indicate a higher development in both mulching treatments compared to the un-mulched treatment although the results were not statistically significant.

Total root

weight(g)

Total root

length (cm)

Fine root length

(cm) (d<2mm)

Medium root

length (cm)

(2mm<d<10mm)

BS

PE

ABF

40.93

47.05

78.23

a

a

b

a

a

b

± 5.87

± 3.48

± 7.89

3416

4479

4683

a

a

a

± 457

± 359

± 1425

3111

4062

4168

a

b

ab

± 409

± 506

± 761

305

417

515

± 104

± 173

± 187

108 Agrobiofilm®

Figure 4.32 – Effect of mulching treatment (ABF, PE and BS) on the dry weight of roots sampled at different depth and distance from the row. Values with different subscripts are considered as significantly different at α=0.05.

0

5

10

15

20

25

a b b

Square 1 Square 2

0

5

10

15

20

25

a

b b

depth

0-2

0 c

m20

-40

cm

40

-60

cm

3030

0

5

10

15

20

25

a a a

30

0

5

10

15

20

25

a a a

30

0

5

10

15

20

25

a aa

30

0

5

10

15

20

25

ab a b

30

BSABFPE

dry

ro

ot

wei

gh

t (g

)

dry

ro

ot

wei

gh

t (g

)

dry

ro

ot

wei

gh

t (g

)

dry

ro

ot

wei

gh

t (g

)

dry

ro

ot

wei

gh

t (g

)

dry

ro

ot

wei

gh

t (g

)

109


The root distribution according to size (Table 4.26) indicates that mulching treatments produced significantly more fine roots (diameter < 2mm) which controlled water and nutrient uptake from soil than for un-mulched treatment. The ABF mulched having the highest number of fine roots almost for all the depths and squares considered (Figure 4.31).

Figure 4.33 – Effect of mulching treatment (ABF, PE and BS) on the length of fine and medium roots sampled at a different depth and distance from the row. Values with different subscripts are considered as significantly different at α=0.05.

a a

fine rootsd<2mm

medium roots2mm<d<10mm

a

a a aa

square 1 square 2

BSABFPE

roo

t le

ng

th (c

m)

roo

t le

ng

th (c

m)

roo

t le

ng

th (c

m)

roo

t le

ng

th (c

m)

roo

t le

ng

th (c

m)

roo

t le

ng

th (c

m)

depth

0-2

0 c

m20

-40

cm

40

-60

cm

fine roots medium roots

a a a a


aa

0

200

400

600

800

1000

1200

0

200

400

600

800

1000 1000

1200

a a a


bba0

200

400

600

800

1000

1200

a a a


aba

0

200

400

600

800

1200

a a a


a

0

200

400

600

800

1200

0

200

400

600

800

1000 1000

1200

aa a

a

a

aaa

110 Agrobiofilm®

Indeed in the first horizon, which is the closest to topsoil, the fine roots of PE treated vines tend to be the most developed probably because the PE mulch film was still intact 25 months after vine planting. Regarding the medium size roots (2mm < diameter < 10mm), which control water nutrients transport and soil exploration the root development, the ABF treatment appeared higher than those of both PE or BS treatments in most of the depths and squares considered (Table 4.26, Figure 4.33). Even in the furthest horizon the root development of un-mulched vines appears lower. Hence in spite of the high variability of the values obtained, the development of vine rootstock appears to be favoured with the ABF treatment. This specific behaviour could probably be related to the progressive disappearance of the mulch film that occurred at the end of the first growing season. This result is in agreement with Van der Westhuizen (1980) who reported a higher root mass of Chenin Blanc vines mulched with plastic film which disintegrated 18 months after planting when compared to un-mulched vines. It could be due to an adaptation of the root system consecutive to the loss of mulch integrity and related changes in soil water content. In the case of permanently mulched vines (like those under PE) it is well known that the rootstock develops mainly close to the soil surface which is a drawback to the newly planted vines in terms of nutrient and water uptake by roots.

In this case, with the ABF treatment, it is likely that there would be loss of water after degradation leading to a reduction in water content under the soil surface this favouring root development deeper in the soil profile in search of water. Therefore the vines treated with ABF mulch film would adopt both the behaviour of the PE treated vines at the soil surface and those of the un-mulched vines in depth. As a result, the root system of vines grown under ABF is more vigorous and better distributed as shown by the root distribution in the different horizon studied (Figures 4.32 and 4.33). This result is also in agreement with a higher turnover of the fine roots and the specific development of plant feeding nematodes two years after vine planting with the ABF treatment.

111


3.9. Conclusions

From this three year study we can conclude:

Agrobiofilm® mulch had a noticeable effect in vine growth.

Vines (Chardonnay) under Agrobiofilm® were harvested 17 months after planting with more than 17 tons per hectare which represented an anticipation of one year regarding vines planted in bare soil.

During the three growing seasons after planting vines initially grown on Agrobiofilm® and PE mulches were both more vigorous and productive than BS ones with a similar behaviour in terms of vegetative growth and production.

Root development is favoured in the case of the ABF treatment not only against BS but also against PE which can be related to ABF deterioration.

Despite the early loss of integrity of the Agrobiofilm® film, which occurred before the end of the first crop cycle, it is worth noting that the mulch enhanced the effect on vine growth, still noticeable during the second and third crop cycles. This suggests that the presence of mulch film at the critical early stage of growth would be as efficient as permanently mulching, i.e. it would allow the plant to grow fast enough to reach economically significant fruiting production in contrast with un-mulched vines.

These first results were quite promising and led to reconsider the lifetime expectancy of mulch film in the case of a perennial crop such as vineyard that would probably be around 4-5 months from the vine planting rather than 18 months as initially targeted.

CHAPTER 5Waste Recovery Options for Mulch Films

115

CHAPTER 5.

Waste Recovery Options for Mulch Films

1. Polyethylene Mulch Removal and Disposal

The major limitation to commercial uses of conventional PE plastics mulches is its after use disposal which causes an environmental pollution problem. Plastic removal from the fields is time consuming and it still requires considerable manual labour even if some of the work is carried out mechanically using appropriate implements. At the end of the crop cycle, when there is time available, farmers remove PE mulch from the soil. Usually, the procedure is to perform an initial cut of the vegetation with a rotary slasher to make PE mulch visible, pictured below in figure 5.1.

Figure 5.1 – Melon experimental field before mulch removal. Six months after planting (October 2010). Five rows on the left are Agrobiofilm® mulch and 5 rows on the right are PE mulch. Azeit-ada, Ribatejo, Portugal.

116 Agrobiofilm®

By using Agrobiofilm® mulch, this initial operation is not necessary thus saving time and money. To lift the mulch two devices can be used. A disc harrow that cuts the mulch film on each bed side (figure 5.2) or a disc harrow and a kind of mould board to lift the mulch which is buried in the edges of the bed (figure 5.3).

Figure 5.2 – Mechanical work on PE mulch removal. (A): The tractor with a disc harrow cut the mulch on the edges, (B): detail of PE mulch fragmentation. Bell Pepper trial (2010), Gran-ho, Ribatejo, Portugal.

As seen in the figure above the remaining manual work consists of intensive labour. It was almost impossible to remove all PE mulch pieces effectively since some pieces were hidden and buried in the soil and also due to the mulch fragmentation phenomenon (figure 5.2B).From the information gathered during the project, directly with our end users, the removal cost associated with PE mulch (lifting, baling and disposal) depends on the film integrity, row length, soil type (e.g., % of sand), inter row distance, availability of suitable machinery and time left from final harvest to remove the mulch.

A B

117

However for crops in open field (melon, pepper, other similar vegetables) a cost discrepancy was found between €146 and €268 per hectare. In relation to the strawberries cultivated under large tunnel the cost of PE mulch removal can rise from €289/ha to €489/ha depending not only on the factors mentioned above but also on whether the operation is completely manual or partially mechanical. This is related to the farmer’s decision whether to remove the metal structure of the greenhouse tunnel. If the structure is not removed plastic from two border lines must be 100% removed manually.

Figure 5.3 – Initial removal operation of PE mulch. Implement with disk harrow and mould boards. Melon trial (2011), Azeitada, Ribatejo, Portugal.

Due to the high costs of the correct disposal of waste PE mulch film these plastics are often discarded in a dump or burned with obvious consequences in terms of toxic substances emissions both to the atmosphere and to the soil (De Prisco et al, 2002).

A

B C

118 Agrobiofilm®

Figure 5.4 – Lifting mulch PE mulch film from soil. (A): in the pepper field trial 2010 and (B): in the melon field trial 2010.

Recycling PE mulch film is also often a complex and costly operation because films are contaminated with too much dirt and debris (figures 5.4 and 5.5).

Figure 5.5 – PE mulch film removed from soil and contaminated with dirt and debris. Melon trial (2011), Azeitada, Ribatejo, Portugal.

A B

119

Some recycling units establish a limit to contaminants. For instance Clark (1996) refers to plastics with more than 5% contaminants by weight will not be accepted for recycling. As a matter of fact contaminants in agricultural plastics can increase in weight by up to 40-50% with pesticides, fertilisers, soil and debris, moist vegetation, silage juice water and UV additives (Amidon, 1994, Hussain & Hamid, 2003, Levitan and Barro, 2003, Rollo, 1997 cited in Kasirajan & Ngouajio, 2012) in particular mulch film and drip irrigation tape which are clearly the most difficult agricultural plastics to be recycled (Lamont 2004). Brooks (1996) reached a similar value (36%) of contamination level for unclean mulch films.

Although it is not a common practice of UE farmers, a highly undesirable end of life plastic mulch are burned on site without energy recovery and even open burning still occurs across the world. For instance Kasirajan & Ngouajio (2012) refers to a study of Levitan & Barro (2003) where it was estimated that more than 50% of agricultural plastics in New York and Pennsylvania were burned on site. The uncontrolled burning of contaminated mulch film with fertilisers and pesticides releases air pollutants especially dioxins that are well known as endocrine disruptors and carcinogens agents (EPA, 2006; Garthe, 2004; Lawrence, 2007; Levitan & Barro, 2003).

Considering the relatively high carbon content of PE (approx. 85%) one may argue that incineration of plastic waste with energy recovery could be a more appropriate option. However most incinerator plants are not designed to burn soil dirt and debris that cover PE plastics and operators are reluctant to do so.

Regarding the landfill option the main criticism is the fact that wastes in general and particularly plastics either do not degrade or degrade at very slow rate and many landfill operators reject PE mulch due to its high contamination levels (Kasirajan & Ngouajio, 2012). In the study of Eriksson and Finnveden (2009) however it was concluded that landfill disposal is preferable to incineration from the point of view of global warming.

To sum up and according to the studies mentioned above, landfill disposable can be the least negative waste management option for the fate of PE mulch film after its useful life.

120 Agrobiofilm®

2. Agrobiofilm Mulch Soil Incorporation

Agrobiofilm mulch can be incorporated in soil together with crop residues and weeds by conventional implements such as a rotary cultivator or a disc harrow at the end of the crop cycle. As it can be observed in the figure below a few months after the end of crop cycle Agrobiofilm® mulch started its degradation which can be faster if it is ploughed in the soil.

Figure 5.6 – Agrobiofilm® mulch before soil incorporation. (A): Melon field, Ribatejo, Portugal (2 months after last harvest) (B): Pepper field, Ribatejo, Portugal (3 months after last hasvest) (C): Strawberry field, Lepe, Spain (2 months after last harvest).

As stated before in this project all crops were cultivated in conventional farms under real conditions and respecting the traditional and usual farmers practices.

A

B

C

121

Each farm has its own dynamics but generally harvest seasons are often very hectic since it is usual for farmers to deal with different crops at the same time. It is quite normal for the workforce to be shifted quickly from crop to crop as soon as possible to maximize harvest yield. There is no time for lesser jobs such since the removal of PE mulch as this can be done at much later stage sometimes a few months later.

Actually in our field trials the soil incorporation of Agrobiofilm® was made at the same time of PE mulch removal (figure 5.7) which was incorporated in the soil several (2-3) months after last harvest.

The best practice would be to plough Agrobiofilm® immediately after harvest. This can be done swiftly by a single tractor which is able to cover many hectares per day and therefore not affecting valuable labour needed for crops. This practice can improve Agrobiofilm® in soil biodegradation rate as the humidity in soil is higher and thus microorganism activity is also higher and it also can begin sooner.

.

Figure 5.7 – Agrobiofilm® mulch needs to be buried in the soil in order to biodegrade faster. The film residues not buried need longer time to biodegrade. Melon field test, Ribatejo, Portugal, 2012.

122 Agrobiofilm®

The advantages for the farmer are thus:

Faster access to the field after last harvest of previous crop.

Easier and cheaper weed management as the quantity of weeds that grow enough to reach seed development can be reduced.

For long cycle crops as strawberries Agrobiofilm® mulch must remained in good condition during 8 to 10 months. This goal was completely achieved, as it can be seen in the figure 5.8.

Figure 5.8 – Agrobiofilm® mulch before in soil incorporation. Lepe, Spain, 2013.

123

The soil incorporation work must be correctly carried out with the disc harrow perfectly adjusted to avoid long portions of Agrobiofilm® mulch remaining intact (Figure 5.9).

Figure 5.9 – Long portions of Agrobiofilm® mulch, improperly ploughed in soil. Lepe, Spain, 2013.

124 Agrobiofilm®

From our experience during three years of intense work with field trials in three different countries, with four different crops and different soils, it is clear that small Agrobiofilm® fragments remaining on top of the soil will not affect the soil quality nor will it compromise subsequent productions. In fact, these pieces will biodegrade easier during the following crop cycle as the microorganism population in soil will rise exponentially with development of newly planted crops.

Figure 5.10 – Small pieces of Agrobiofilm® mulch on top of the soil in different soils, Lepe, Spain, 2013.

125

3. Agrobiofilm Mulch Soil Biodegradation

Biodegradable plastics in soil are defined as plastics in which the degradation process results from the action of microorganisms such as bacteria, fungi and algae that naturally occurs in nature (in real soil conditions). Unfortunately, no EU standard that determines the testing conditions of a biodegradable polymer for biodegradation in soil is yet currently available (at the present time- August 2013). Most of the existing international standards for biodegradable materials are planned for testing biodegradation under different conditions in a variety of media but not for specifically testing biodegradation in soil especially in agricultural soil that is used for production of food (Briassoulis & Dejean, 2010).

However there is a French norm for testing biodegradability of agricultural films in soil, NF U52-001 (AFNOR, 2005) and the International Organization for Standardization norm ISO 17556 - Determination of the ultimate aerobic biodegradability in soil by measuring the oxygen demand in a respirometer or the amount of carbon dioxide evolved.

Our films were produced and tested for horticulture and perennial crops and therefore the soil biodegradation results presented in this chapter are from Vineyard soil (France) using the French norm NF U52-001 and Bell pepper soil (Portugal) using the International norm ISO 17556.

Despite not being clearly written, it has been widely discussed during the implementation of the standard NF U52-001 and thus the deadline time for the respirometric test in soil is one year for short time mulch resistance (as for example horticultural crops). However there is a broad mindedness for two years for the long time mulch resistance as mulch used in vineyards and other perennial crops (Cesar, 2013).

The next figure shows the kinetics of biodegradation based on respirometric tests (carbon dioxide release) monitored in aerobic conditions in a soil sample from vineyard (1.35% organic matter) at 28°C.

126 Agrobiofilm®

Figure 5.11 - Biodegradation of Agrobiofilm® mulches used in vineyard. ABF made with 100% virgin raw material and ABF2 with incorporation of 10 % scrap, Blomac, France, 2012.

The test was validated since cellulose exhibited a 70% degradation level after 145 days of incubation which is less than the 183 days threshold requested by the French standard NF U52-001 in relation to mulching materials. Then the kinetic of biodegradation of ABF and ABF2 are almost identical and both compositions fulfill NF U52-001 standard requirements concerning biodegradability. Indeed the 60% degradation level (in comparison to cellulose) is reached by the two compositions between 450 and 500 days which is less than the 2 years allowed by the standard for perennial crops.

It is worth mentioning that to comply with the NF U52-001 another test should be carried out. Either a test in compost or a Stürm test conducted in liquid medium. However the biodegradation patterns are very slow due to

100

80

60

40

20

0

Bio

deg

rad

atio

n (%

)

time (days)

0 100 200 300 400 500 600

CelluloseABFABF2

127

soil quality. Indeed vineyard soils (such as the present one) are known to be poor in organic matter and nutrients. Consequently it is relevant to infer from the respirometric results that Stürm and compost tests would be passed by ABF and ABF2.

In horticultural crops the biodegradable mulches are meant to be incorporated in the soil and so it is important to understand the effect of their incorporation and biodegradation in soil. It is also crucial that the mulch film biodegradation does not interfere with subsequent crops.The results can be observed in figure 5.12, of the ongoing biodegradation test performed with a loamy soil (2.5 % organic matter) and Agrobiofilm® mulch from the second bell pepper trial performed at 25ºC.

Fig. 5.12 Biodegradation of Agrobiofilm® mulches used in bell pepper trial, Ribatejo, Portugal, 2012.

100

80

60

40

20

0

Bio

deg

rad

atio

n (%

)

time (days)

1 11 21 31 45 51 61 71 81 91 101 111 121 131 141 151 161

CelluloseAgrobiofilm

128 Agrobiofilm®

Concerning ISSO 17556, there is no threshold for the biodegradation rate but the test is terminated when a constant level of biodegradation has been attained or, at the latest, after six months.

As showed in the figure 5.12, Agrobiofilm® reached more than 70% of biodegradation in 160 days. Assuming the same rate, it is expectable a complete biodegradation in less than one year, which is a very positive result.

CHAPTER 6Life Cycle Assessment and Potential for Wider Applications of Agrobiofilm Mulch

133

CHAPTER 6.

Life Cycle Assessment and Potential for Wider Applications of Agrobiofilm Mulch

1. IntroductionThe aim of this chapter is to document potential environmental benefits of:

(1) Using mulch films in crop production vs bare soil, and (2) Replacing presently used PE with the biodegradable mulch film Agrobiofilm®.

The life cycle analysis (LCA) was carried out using data collected from the production of PE and Agrobiofilm® as well as production of vegetables/fruits with and without the application of mulch films (PE and Agrobiofilm®). The four crops selected for the study were muskmelons, bell peppers, strawberries and grapes for wine (hereafter referred to as vineyards).

2. Results and Discussion2.1 Bell Pepper LCA Environmental Impact

A first comparison between BS and the other two alternatives PE and Agrobiofilm® shows that the environmental performance per kg of bell peppers produced with the use of either PE much film or Agrobiofilm® was improved from that produced without the use of the films. The improvement i.e. the reduction in environmental impacts per kg produced was found for all impact categories ranging from 7 to 55% reduction of which the highest range is noted for eutrophication. Interestingly, on a per ha basis, the “saved” environmental costs associated with the use of the films favour the environmental performance of the BS system over Agrobiofilm® and PE (except eutrophication) but on a per kg basis the 40% lower yield makes the system no longer a better choice than its alternatives. For eutrophition the higher impact per ha of the BS system compared to the other two alternatives is due to a higher leaching rate of both nitrogen and phosphorus.Next table presents the LCA results for the production of bell pepper in three systems: ABF, PE and BS. The results are first calculated per ha and then converted to per kg of peppers.

134 Agrobiofilm®

Tab

le 6

.1 L

CA

res

ult

s fo

r th

e p

rod

uct

ion

of

bel

l pep

per

in t

hre

e sy

stem

s: A

gro

bio

film

® (A

BF)

, PE

an

d b

are

soil

(BS)

No

te: L

ife

cycl

e as

sess

men

t (L

CA

); G

lob

al w

arm

ing

(GW

P);

No

n-r

enew

able

en

erg

y u

se (N

RE

); E

utr

op

hic

atio

n (E

P).

* Y

ield

in P

E #

yie

ld in

AB

F =

80

t/h

a; Y

ield

in B

S =

49

t/h

a

GW

Pkg

CO

eq

L

CA

B

ell-

pep

per

2

NR

EG

J p

rim

ary

EP,

aq

uat

ickg

NO

-eq

3

EP,

ter

rest

rial

m U

ES

2

Res

. in

org

anic

sg

PM

2.5

-eq

Mu

lch

film

Ag

roch

emic

als

and

org

. fer

t.H

erb

icid

eE

lect

rici

tyT

ract

ion

PE

en

d-o

f-li

feE

mis

sio

ns

Sum

per

ha

Sum

per

kg

p

epp

er

44

89

58

0 98

04

190 9

63

3770

0.0

5

69

49

58

0 98

04

196

179

539

07

0.0

5

0 958

7 98

039

10 8

85

3220

0.0

7

11.0

12.3

0 19.8

6.1

0 49

.20

.6 x

10

18.6

12.3

0 19.8

6.1

0.7

57.5

0.7

x10

0 12.3

0.1

19.8

5.7

0 38.0

0.8

x10

0.5

32.6

0 0.0

70

.33

0 179

.421

32.

7 x

10

0.2

32.6

0 0.0

70

.33

0.0

419

0.4

224

2.8

x10

0 32.6

0.2

60

.07

0.3

10 25

6.3

290

6 x

10

87

119

0 32 152

0 1024

1414

0.0

2

85

119

0 32 152

18 1024

1430

0.0

2

0 119

0.4

32 142

0 1024

1318

0.0

3

513

956

0 143

654

0 118

434

500

.04

598

956

0 143

654

66

118

436

00

0.0

5

0 956

5 143

610

0 118

428

99

0.0

6-3

-3-3

-3-3

-3

AB

F P

E

BS

AB

F P

E

BS

A

BF

PE

B

S

AB

F P

E

BS

A

BF

PE

B

S

135

The comparison between the two systems using mulch films shows that the non-renewable energy reduction benefits acquired when Agrobiofilm® is used instead of PE are reasonable (15%) whereas those in other impact categories are relatively minor if not negligible (less than 1.5% in eutrophication, terrestrial and less than 5% in global warming, respiratory inorganics and eutrophication, aquatic). The favourable environmental performance of the Agrobiofilm® system compared to the PE in non-renewable energy use, global warming, and respiratory inorganics is due to the following favourable aspects:

1) a cheaper environmental cost per kg film input; 2) a lower amount of the film used per ha; and 3) the extra costs associated with PE film end-of-life management (film removal, transport and disposal) though the latter has a relatively minor contribution.

In the case of eutrophication where the environmental costs of Agrobiofilm® are much higher than those of PE the potential benefits of the biofilm system vs. the PE due to a lower amount of film used and the extra costs associated with PE film end-of-life management are not large enough to generate a reasonable net reduction in eutrophication when PE is replaced with Agrobiofilm® in bell pepper production.

2.2 Vineyard LCA Environmental Impact

The results comparing environmental impacts of vineyard production using mulch films (PE and Agrobiofilm®) vs. bare soil are presented in Table 6.2.It is clear from the table that there is an improvement in eutrophication when applying mulch films to soil as opposed to leaving the soil uncovered in vineyard production whereas no improvement is found regarding the other impact categories. Due to the impact associated with the use of the films the environmental costs of the BS system on a per ha basis are lower than those of PE and Agrobiofilm® systems and this relative performance remains unchanged or changed depending on impact category when calculated on a per kg grape basis. Considering “non renewable energy use” the consequences of not using mulch films are the savings of up to 50% energy use for the films and the reduction of 40% in yield.

136 Agrobiofilm®

Tab

le 6

.2. L

CA

res

ult

s fo

r th

e p

rod

uct

ion

of

vin

eyar

ds

in t

hre

e sy

stem

s: A

gro

bio

film

® (A

BF)

, PE

an

d b

are

soil

(BS)

, co

nsi

der

ing

th

e fi

rst

two

yea

rs a

fter

est

ablis

hm

ent

No

te: L

ife

cycl

e as

sess

men

t (L

CA

); G

lob

al w

arm

ing

(GW

P);

No

n-r

enew

able

en

erg

y u

se (N

RE

); E

utr

op

hic

atio

n (E

P).

* Y

ield

in P

E #

yie

ld in

AB

F =

14

.7 t

/ha;

Yie

ld in

BS

= 8

.9 t

/ha

(ave

rag

e re

sult

s o

f 2

har

vest

s)

GW

Pkg

CO

eq

L

CA

Vin

eyar

ds

2

NR

EG

J p

rim

ary

EP,

aq

uat

ickg

NO

-eq

3

EP,

ter

rest

rial

m U

ES

2R

es. i

no

rgan

ics

g P

M 2

.5-e

q

Mu

lch

film

Ag

roch

emic

als

Ele

ctri

city

Tra

ctio

nP

E r

em.,

dis

., tr

ans.

Em

issi

on

s

Sum

per

ha

Sum

per

kg

gra

pes

556

246

48

621

00 -4

7

523

246

48

621

034 -2

71

0 166

48

621

00 -1

91

13.8

3.2

9.8

3.1

0

14.0

3.2

9.8

3.1

0.4

0 2.3

9.8

3.1

0

0.6

41.

49

0.0

30

.17

0 1.4

7

0.1

41.

49

0.0

30

.17

0.0

31.

51

0 1.4

20

.03

0.1

70 3.

03

110

37 16 76 0 459

64

37 16 76 11 459

0 16.8

16 76 0 398

.5

64

017

771 32

70 4

51

450

177

71 327

48

451

0 110

71 327

0 366

1450

0.1

0

1230

0.0

8

670

0.0

8

29.9

2.0

x

10-3

30.5

2.1

x

10-3

15.2

1.7

x

10-3

3.8

0.2

6 x

10-3

3.4

0.2

3 x

10-3

4.6

0.5

2 x

10

-3

69

8

0.0

5

66

2

0.0

5

508

0.0

6

166

6

0.1

1

1520

0.1

0

874

0.1

0

AB

F

PE

BS

A

BF

P

E

BS

AB

F

P

E

BS

AB

F

PE

BS

AB

F

PE

B

S

137

The larger magnitude of energy savings compared to that of yield reduction as a result of not using mulch films is the reason making the NRE score per kg of grapes in BS system more favorable than that in the two alternatives. This is contrary to the results for bell peppers where the magnitude of the yield reduction when biodegradable and polyethylene mulch films are not used is larger than that of the energy savings 40% vs. 23% and 40% vs. 34% respectively (see Table 6.1).

The comparison between the two systems using mulch films shows that using Agrobiofilm® to cover the soil instead of PE film in vineyard production would reduce non-renewable energy use (2%) but increase global warming (18%), eutrophication, aquatic (12%), respiratory inorganics (10%) and eutrophication, terrestrial (5%). The reduction in non-renewable energy use however can be considered as insignificant. In relation to global warming and non-renewable energy use the much higher amount of Agrobiofilm® use per ha in vineyards compared to that of PE completely offset the advantage of a cheaper environmental cost per kg of film input. In relation to other impact categories like eutrophication and respiratory inorganics where the biofilm shows an inferior performance compared to the PE film, the use of a much higher amount of biofilm makes the performance of the Agrobiofilm® system even less favourable than the PE system.

However it is worth mentioning that the calculations performed for vineyard crop were based on the two-year average data which assume that PE gives the same yield of grapes as Agrobiofilm®. Data that sourced from a relatively short period compared to the crop growing cycle (20-30 years for vineyard) may not reveal the long-term potential of yield improvement through the use of biodegradable films as an alternative to polyethylene plastic mulches in vineyard production. Thus, as reported before Agrobiofilm® seems to stimulate a better (deeper more, more vigour) root development which might improve the persistence of the grape yield over the coming years of production. If we make an assumption that the yield of grapes in the PE system stays the same and the yield by use of Agrobiofilm® is improved by 20% this would lead to a superior environmental performance of the Agrobiofilm® over the PE on a per kg of grapes basis.

138 Agrobiofilm®

These results are based in vineyard trials with same thickness values for PE and Agrobiofilm® mulches (40 microns). New trials are ongoing both in France and Portugal with Agrobiofilm® mulch in 25 microns. The results are very promising and it will be possible to reduce the mulch quantity per hectare.

2.3 Muskmelon LCA Environmental Impact

Next table presents the LCA results for the production of muskmelons using PE mulch film vs. Agrobiofilm®. The results are first calculated per ha and then converted to per kg of muskmelons.

As shown in the table the reduction benefits in non-renewable energy use acquired when Agrobiofilm® is used instead of PE are reasonable (19%), whereas those in other impact categories are relatively minor. The advantages of the biofilm system compared to the PE system in non-renewable energy use, global warming, and respiratory inorganics clearly result from:

1) a lower amount of the film used per ha; 2) a cheaper or similar environmental cost per kg film input; and 3) the extra costs associated with PE film end-of-life management (film removal, transport and disposal) though the latter has a relatively minor contribution.

In the case of eutrophication where the environmental costs of ABF are much higher than those of PE the potential benefits of the biofilm system vs. PE due to the lower amount of film used and the extra costs associated with PE film end-of-life management are not large enough to generate a significant net reduction in eutrophication when PE is replaced with Agrobiofilm® in muskmelon production.

139

Tab

le 6.3. E

nviro

nm

ental im

pacts o

f mu

skmelo

n p

rod

uctio

n u

sing

Ag

rob

iofi

lm®

(AB

F) vs. PE

mu

lch fi

lm

No

te: Life cycle assessm

ent (L

CA

); Glo

bal w

armin

g (G

WP

); No

n-ren

ewab

le energ

y use (N

RE

); Eu

trop

hicatio

n (E

P).

* Yield

in P

E #

yield in

AB

F = 23 t/h

a

GW

Pkg

CO

eq

LC

Am

uskm

elon

2

NR

EG

J prim

aryE

P, aqu

atickg

NO

-eq3

EP, terrestrial

m U

ES

2R

es. ino

rgan

icsg

PM

2.5-eq

Mu

lch fi

lmC

om

m. ag

roch

emicals

and

man

ure

Electricity

Tractio

nP

E en

d-o

f-lifeE

missio

ns

Su

m p

er h

a

Su

m p

er k

g

mu

skm

elo

n

32414

57

622801274

569

1457

6228341153

8.0

21.2

0.1

3.30

15.221.2

0.1

3.30

.4

0.4

-3.2

0.0

0.2

564

.0

0.2

-3.2

0.0

0.2

0.0

572.0

63

-618

6

0.2

83

7539

69

-618

6

0.2

83

7753

9

372-34

51

0.9

356

66

46

49

1-34

51

0.9

356316

64

6

32

90

0.14

34

50

0.15

32

.6

1.4 x

10-3

40

.2

1.8 x

10-3

56

1.4

24

.4 x

10-3

56

9.2

24

.7 x

10-3

150

0

0.0

65

1513

0.0

66

39

70

0.17

412

0

0.18

AB

F PE

AB

F PE

AB

F PE

AB

F PE

AB

F PE

140 Agrobiofilm®

2.4 Strawberry LCA Environmental Impact

The results comparing environmental impacts of strawberry production using PE mulch film vs. Agrobiofilm® are presented in Table 6.4.

The comparison either per ha or per kg basis shows that using Agrobiofilm® to cover the soil instead of PE film in strawberry production has some positive effects in terms of non-renewable energy use (9% reduction), global warming and respiratory inorganics (4% reduction) but negligibleeffects in eutrophication. The reduction is accounted for by the contribution from the three main factors:

1) a lower amount of the film used per ha; 2) a cheaper or similar environmental cost per kg of film input; and 3) the extra costs associated with PE film end-of-life management (film removal, transport and disposal) of which the contribution from the first and second factor combined is more important than the third (66% vs. 34% for respiratory inorganics, 72% vs. 28% for global warming and 91% vs. 9% for non-renewable energy use).

In the case of eutrophication where the environmental costs of Agrobiofilm® are much higher than those of PE, the potential benefits of the biofilm system vs. the PE due to the lower amount of film used and the extra costs associated with PE film end-of-life management are not large enough to generate a net reduction in eutrophication when PE is replaced with Agrobiofilm® in strawberry production.

141

Tab

le 6.4

. En

viron

men

tal imp

acts of straw

berry p

rod

uctio

n u

sing

Ag

rob

iofi

lm®

(AB

F) vs. PE

mu

lch fi

lm

No


ent (L

CA

); Glo

bal w

armin

g (G

WP

); No

n-ren

ewab

le energ

y use (N

RE

); Eu

trop

hicatio

n (E

P).

* Yield

in P

E #

yield in

AB

F = 72.6

t/ha

GW

Pkg

CO

eq

LC

AStraw

berry

2

NR

EG

J prim

aryE

P, aqu

atickg

NO

-eq3

EP, terrestrial

m U

ES

2R

es. ino

rgan

icsg

PM

2.5-eq

Mu

lch fi

lmA

gro

chem

icalsE

lectricityT

raction

PE

end

-of-life

Em

ission

s

Su

m p

er h

aS

um

pe

r kg

straw

be

rries

611

37704

790

3970

02586

125037704

790

3970

1512330

153497

58

333497

582

1103

03617

0103

030633

1194

93

15814

40

2229

152

49

315

814

40

42

.92

22

9

701

2421

69

96

190

2708

108

024

216

99

619

019

7270

8

157

27

0.2

216

26

00

.22

20

52

.8 x

10

-3

22

53

.1 x

10-3

72

40

.01

74

00

.01 4

43

90

.06

45

140

.06

127

190

.1813

29

50

.18

AB

F PE

AB

F PE

AB

F PE

AB

F PE

AB

F PE

142 Agrobiofilm®

2.5 Agrobiofilm® vs PE Mulch LCA summary

The LCA results on a per kg of fruits/vegetables basis and on a per ha basis comparing the use of Agrobiofilm® vs PE are presented in table 6.5. Data on yield of each crop are also presented in the table to facilitate comparison among crops and between the use of Agrobiofilm® and PE mulch film.

Regarding global warning the use of Agrobiofilm® results in a small reduction in GWP impact (3-5%) compared to PE. Contrary to that the use of non-renewable energy use (NRE) was reduced by 19%, 14% and 9% respectively, compared to the use of PE.

The comparison between the use of the two mulch films in the three crop production systems shows that the benefits of using Agrobiofilm® over PE in aquatic eutrophication if any was very minor and the same holds for terrestrial eutrophication. This is explained by:

(1) the largest contribution to the impact in this category comes from the field emissions of NH and NOx which are estimated from the amount of fertiliser nitrogen and/or manure nitrogen used; and (2) that the rate of fertiliser and/or manure use in crop production using Agrobiofilm® is not different from that using PE.

For respiratory inorganics the use of Agrobiofilm® reduced the impact by approx. 4% compared to the use of PE.

In order to further enhance the environmental performance of biodegradable mulch film other sources of bio-material than starch should be considered. We are aware that there are efforts to base the source of biomass on high yielding perennial crops that requires low inputs of fertiliser and chemicals for plant protection. This is an effort that should be stimulated.

3

143

Tab

le 6.5. Su

mm

ary of L

CA

results fo

r the th

ree ann

ual cro

ps w

ith th

e use o

f Ag

rob

iofi

lm® (A

BF) vs. P

E

No


ent (L

CA

); Glo

bal w

armin

g (G

WP

); No

n-ren

ewab

le energ

y use (N

RE

); Eu

trop

hicatio

n (E

P).

Bell p

epp

erL

CA

sum

mary resu

ltsM

uskm

elon

Strawb

erries

Yield

kg/h

a

GW

P, g C

O eq

/kgG

WP, kg

CO

eq/h

a

No

n-ren

ew. en

ergy,

MJ p

rimary/kg

No

n-ren

ew. en

ergy,

GJ p

rimary/h

a

EP, aq

uatic, g

NO

-eq/kg

EP, aq

uatic kg

NO

-eq/h

a

EP, terrestrial, m

UE

S/kgE

P, terrestrial, m U

ES/h

a

Res. in

org

anics, g

PM

2.5-eq/kg

Res. in

org

anics, g

PM

2.5-eq/h

a

80

00

0

47

3770

0.6

49

.3

2.7213

0.0

214

10

0.0

434

50

80

00

0

49

390

0

0.7

57.5

2.8224

0.0

214

30

0.0

536

00

2300

0

143

3290

1.4

32.7

24.4

562

0.0

7150

0

0.17

3970

2300

0

15034

50

1.8

40

.2

24.8

570

0.0

71510

0.18

4120

7260

0

21715727

2.8

205

10.0

724

0.0

64

439

0.18

12719

7260

0

22416

260

3.1

225

10.2

740

0.0

64

514

0.18

13295

AB

F PE

AB

F PE

AB

F PE

22

33

22

144 Agrobiofilm®

3. Conclusions

Based on the results of the study the following main points of conclusions can be drawn regarding the environmental consequences of using Agrobiofilm® mulch film:

The environmental performance of bell peppers produced with the use of either PE mulch film or Agrobiofilm® is improved from that produced without the use of the films.

Use of Agrobiofilm® compared with PE in the three annual crop production systems muskmelons, bell peppers and strawberries shows that the advantage of Agrobiofilm® over PE is a reasonable reduction in non-renewable energy use (19%, 14% and 9%, respectively). Whereas very little or no advantage is found regarding the other impact categories (global warming, eutrophication and respiratory inorganics).

CHAPTER 7Organic Farming, its Importance and EU Incentives to Biodegradable Mulch Film

149

CHAPTER 7.

Organic Farming, its Importance and EU Incentives to Biodegradable Mulch Film

1. Introduction

Organic farming is an agricultural system that seeks to provide the con-sumer with fresh tasty and authentic food while respecting natural life-cy-cle systems. To achieve this, organic farming relies on a number of objec-tives and principles, as well as common practices, designed to minimise the human impact on the environment while ensuring the agricultural sys-tem operates as naturally as possible.

Typical organic farming practices include:

Wide crop rotation as a prerequisite for an efficient use of on-site resources; Very strict limits on chemical synthetic pesticide and synthetic fertiliser

use, livestock antibiotics, food additives and processing aids and other inputs; Absolute prohibition in using of genetically modified organisms; Taking advantage of on-site resources such as livestock manure for

fertiliser or feed produced on the farm; Choosing plant and animal species that are resistant to disease and

adapted to local conditions; Raising livestock in free-range, open-air systems and providing them

with organic feed;

Organic farming is also part of a larger supply chain which encompasses food processing, distribution and retailing sectors and ultimately consumers. Each link in this supply chain is designed to play an important role in delivering the benefits associated with organic food production across a wide range of areas including environmental protection, animal welfare; consumer confidence and society and economy.

150 Agrobiofilm®

The current EU organic legislation1 sets out rules for plant and animal production and for the processing of food and feed to be labeled as organic. Compliance with EU organic legislation is required for all products carrying the EU organic logo. In order to be able to trace organic products the name or code number of the certification body that has certified the organic producer has to be on the label.

Figure 7.1 – New EU organic logo. From July 2010 is obligatory for all organic pre-packaged

food products within the European Union.

2. Market Trends

All over the world, particularly within the EU, consumers are choosing to buy organic food and drink.

Whether it is out of a desire for tasty and authentic food or to contribute to the protection of the environment, improvement of natural resources, animal welfare and rural communities the statistics show organic consumption is on the rise.

1. http://ec.europa.eu/agriculture/organic/organic-farming/what-organic_en)

151

According to “An analysis of the EU organic sector” (2010) this sector amounts to an estimated 7.6 million ha in 2008, i.e. 4.3% of EU-27 UAA (more 7.4% per year from 2000-2008). In absolute terms the Member States with the largest areas in 2008 was Spain (1.13 million ha), Italy (1.00 million ha), Germany (0.91 million ha), the United Kingdom (0.72 million ha) and France (0.58 million ha). Altogether they represent 56.8% of the EU organic farming.

Figure 7.2 – Share of the organic area in the total UAA in 2007 at regional level (%). Adapted from http://ec.europa.eu/agriculture/organic/files/eu-policy/data-statistics/facts_en.pdf.

Share of organic farming in the UAA(%)

<1%1 - 2,5%2,5 - 5%5 - 10%> 10%N.A.

EU-27 Average: 4.0%

0 150 500 750 km

152 Agrobiofilm®

As it can be seen in figure 7.2, there is a strong heterogeneity within most countries regarding the weight of the organic sector. In France, Italy and Spain the organic sector is more important in southern regions. In Spain the organic sector is clearly concentrated in the South with almost 60% of the organic area located in Andalusia. The “World of Organic Agriculture” (2007) estimated European sales of organic products were worth between €13-14 billion in 2005 with the biggest market being Germany which had annual sales of €3.9 billion at the time. This was followed by fellow EU countries Italy and France with annual turnovers of €2.4 billion and €2.2 billion respectively. The annual growth in the market for organic products is between 10-15%.

3. Organic Farms Weed Management

Organic farmers are keen to develop effective and economical weed management. In fact farmers rank weeds as the number one barrier to organic production (Walz, 1999). The main goal in weed management within an organic system is to reduce weed competition and reproduction to an acceptable level. In many cases this will not eliminate completely all weeds but, preventing the production of weed seeds and perennial propagules, provides a reduction of competition from current and future weeds (Finney et al., not dated1). This study clearly states: “Although black plastic is commonly used as a mulching material, its environmental impact conflict with the goals of regenerative and sustainable production. Synthetized from petroleum, plastic represents a significant use of nonrenewable fossil fuels. In addition, the disposal of plastic mulch has contributed to current landfill problems throughout the United States.”

2. http://www.cefs.ncsu.edu/resources/organicproductionguide/weedmgmtjan808accessible.pdf

2

153

According to our project results, Agrobiofilm® mulch can be considered a viable substitute to PE mulch. We strongly believe that EU should revise the rules of organic farming and to prohibit the use of both single PE and

PE with additives.

4. EU Agri-Environment Measures

For the period 2007-2013 Council Regulation (EC) 1698/2005 offers the basis for agri-environmental measures (article 39). Agri-environmental measures are part of the thematic Axis 2 “improving the environment and the countryside through support for land management” of the regulation. Payments for organic commitments are annual, per hectare and are meant to cover the additional costs incurred and the income forgone (e.g., due to lower yields) as a result of organic production methods.

Support to Producer Organisations (PO) in the fruit and vegetables sectors has existed in the EU since 1997. Initially the aid scheme for PO was under heavy criticism as withdrawals and export refunds consumed a major part of the aid to the sector. The reform of market organisation, that was discussed and agreed in 2007, included among other things a revision of legislation on PO support. One result is that each member state must present a National Strategy for the implementation of a PO scheme. The National Strategy is the framework for the PO to draw up individual Operational Programmes. When the Operational Programme and all its measures are designed environmental aspects shall always be taken into consideration, however each member state can choose the measures and support level.In Portugal, Spain and France the utilisation of biodegradable plastic mulch is clearly supported by PO scheme, and farmers are partially refund with the cost difference between biodegradable and conventional PE mulch.

154 Agrobiofilm®

The actual subsidy value in Portugal (according to Portuguese legislation, namely “Portaria nº 1325/2008” and “Procedimento Operativo PO-0004-DSFAA, GPP/MAMAOT) covers 52.2% of the cost of biodegradable mulch.

Spanish funding is 35% of the Biodegradable invoice (Real Decreto 1337/2011 and “Estrategia Nacional de los programas operativos sostenibles a desarrolar por las organizaciones de productores de frutas y hortalizas”).

It is clear that without these incentives schemes, it would be difficult to convince farmers to switch from normal PE to biodegradable mulch since cost is still the major barrier.

As explained before (Chapter 1) oxo-degradable plastic has different characteristics and according the DEFRA study its degradation is questionable. We believe the funding schemes mentioned before (Portugal and Spain) should be revised in order to positively discriminate the utilisation of real biodegradable and compostable films.

Finally we also believe that these incentives should have a broader reach and include farmers that are not associated to a PO and its formalities should be less bureaucratic.

The utilisation of synthetic plastic mulch (singe PE or with additives) is absolutely against the ideal of a regenerative and sustainable production claimed by organic farming, especially when alternatives such as Agrobiofilm® mulch are technically sound and commercially available.

157

REFERENCES

Albertsson, A.C., Huang, S.J., (1995). Degradable polymers, recycling and plastics waste management. Marcel Drekker, New York;

AFNOR (2005). NF U52-001: Biodegradable materials for use in agriculture and horticulture mulching products. Requirements and test methods;

Almeida, D., (2006). Manual de Culturas Hortícolas. Volume II. Editorial Presença, Lisboa;

AMI (2010/2011). http://www.amiplastics.com/;

Amidon, (1994) Use and disposal of plastics in agriculture. Prepared by Amidon Recycling for the American Plastics Council;

An analysis of the EU organic sector (2010). European Commission Directorate-General for Agriculture and Rural Development;

Briassoulis, D., (2007). Analysis of the mechanical and degradation performances of optimized agricultural biodegradable films. Polymer Degradation and Stability 92: 1115-1132;

Briassoulis, D., Dejean, C., (2010). Critical review of norms and standards for biodegradable agricultural plastics. Part I. Biodegradation in soil. J Polym Environ 18(3): 384-400;

Brooks, T.W., (1996). Method and apparatus for recycling previously used agricultural plastic film mulch. U.S. patent nº 5510076;

César, G., (2013). President of SERPBIO. Personnel communication.

CIPA (2006). International Committee of plastics in agriculture;

Clarke, S.P., (1996). Recycling farm plastic films fact sheet. http://www.omafra.gov.on.ca/english/engineer/facts/95-019.htm. Assessed in September 2012

Council Directive 1999/31/EC of 26 April 1999 on the landfill of waste, Official journal L 16/07/1999, 182:1-19;

158 Agrobiofilm®

Council Regulation (EC) No 1698/2005 of 20 September 2005 on support for rural development by the European Agricultural Fund for Rural Development (EAFRD);

Csizinszkv, A. A., Schuster, D. J., King, J.B., (1995). Color mulches influence yield and pest populations in tomatoes, J. Amer. Soc. Hort. Sci. 120: 778-784;

De Prisco, N., Immirzi, B., Malinconico, M., Mormile, P., Petti, L., Gatta, G., (2002). Preparation, physico-chemical characterization and optical analysis of polyvinyl alcohol-based films suitable for protected cultivation. J Appl Polym Sci 86:622-632;

DEFRA (2010). EV0422, Assessing the environmental impacts of oxo-degradable plastics across their life cycle. Loughborough University;

Directive 2000/76/EC of the European Parliament and of the Council of 4 December 2000 on the incineration of waste;

EPA (2006). An inventory of sources and environmental releases of dioxin-like compounds in the USA for the years 1987, 1995 and 2000. National Center for Environmental Assessment , Washington, DC;

Eriksson, O., Finnveden, G., (2009). Plastic waste as fuel – CO2 neutral or not – Energy & Environmental Science, 2(9): 907-914;

Farooqi, A.A, Sreeremu, B.S, (2005). Cultivation of spice crops, University press, 336pp;

Ganapini, W., (2013). Bioplastics: A case study of bioeconomy in Italy. Edizione Ambiente, Milano, Italy. 159pp;

Garthe, J., (2004). Managing used agricultural plastics. In: Lamont, W., (Ed) Production of vegetables, strawberries and cut flowers using plasticulture. NRAES, Ithaca;

Godden, G.D., Hardie W.J., (1981). Comparison between grapevine response to polyethylene mulch and herbicide control of weeds. Gartenbauwissenschaft 46(6):277-284;

Greer, L., Dole, J.M., (2003). Aluminium foil, aluminium-painted, plastic and degradable mulches increase insect-vectored viral diseases of vegetables. HortTechnology 13: 276-284;

159

Halley, P., Rutgers, R., Coombs, S., Kettels, J., Gralton, J., Christie, G., Jenkins, M., Beh, H., Griffin, K., Jayasekara, G., (2001). Developing biodegradable mulch films from starch-based polymers. Starch 53: 362-367;

Hemphill, D.D., (1993). Agricultural plastics as solid waste: what are the options for disposal? HortTechnology 3: 70-73;

Hussain, I., Hamid, H., (2003). Plastics in agriculture. In: Andrady, A.L., (Ed.) Plastics and the environment. Wiley, Hoboken, pp 185-209;

ISO 17556 (2012). Plastics — Determination of the ultimate aerobic biodegradability of plastic materials in soil by measuring the oxygen demand in a respirometer or the amount of carbon dioxide evolved;

Kasirajan, S., Ngouajio, M., (2012). Polyethylene and biodegradable mulches for agricultural applications: a review. Agron Sustain Dev 32:501-529;

Lamont, W. J., (2005). Plastics: modifying the microclimate for the production of vegetable crops. HortTechnology 15: 477-481;

Lamont, W., (2004). Plasticulture: an overview. In: Lamont, W., (Ed) Production of vegetables, strawberries and cut flowers using plasticulture. NRAES, Ithaca;

Lawrence, M.J., (2007). A novel machine to produce fuel nuggets from no-recyclable plastics. Agricultural and Biological. PhD dissertation. The Pennsylvania State University, University Park;

Levitan, L., Barro, A., (2003). Recycling agricultural plastics in NY state. Environmental risk analysis program, Cornell Center for the Environment, Cornell University, Ithaca.

Lorenz, D.H., Eichhorn, K.W., Bleiholder, H., Klose, R., Meier, U., Weber, E., (1994). “Phänologische Entwicklungsstadien der Weinrebe (Vitis vinifera L. ssp. vinifera), Vitic. Enol. Sci. 49: 66–70;

Martin-Closas L., Soler, J., Pelacho, A.M., (2003). Effect of different Biodegradable mulch materials on an organic tomato production system. KTBL schrift 414: 78-85;

Minuto, G., Pisi, L., Tinivella, F., Bruzzone, C., Guerrini,S., Versari, M., Pini, S., Capurro, M., (2008). Weed control with biodegradable mulch in vegetable crops. Proceedings of the International Symposium on High Technology for Greenhouse System Management, Vols 1 and 2(801): 291-297;

160 Agrobiofilm®

Moore, R.C., (1963). Plastic mulch aids growth of young grape vines and cuttings. Biokemia 1(1): 21-23;

OMAIAA (2012) in www.observatorioagricola.pt assessed in 13-12-2012;

Orzolek, M., (2010). Pennsylvania commercial vegetable production guide, University Park, Penn State cooperative extension;

Pinamonti, F., (1998). Compost mulch effects on soil fertility, nutritional status and performance of grapevine. Nutrient Cycling in Agroecosystems 51(3): 239-248;

Portaria nº 1325/2008 de 18 de Novembro, Diário da República 1ª Série nº 224: 8085-8090;

Real Decreto 1337/2011, de 3 de octubre, por el que se regulan los fondos y programas operativos de las organizaciones de productores de frutas y hortalizas.

Rollo, K.L., (1997). Agricultural plastics – boon or bane?

Seymour, R.B., (1989). Polymer science before & after 1989: notable developments during the lifetime of Maurtis Dekker. J. Macromol Sci Chem 26: 1023-1032;

SRA (1977) - Secretaria de Estado da Agricultura – Recognition service of agriculture, Portuguese land use capacity charter-31;

Stoltzfus, R., Taber, H., Aiello, A., (1998). Effect of increasing root zone temperature on growth and nutrient uptake by ‘gold star’ muskmelon plants. Journal of Plant Nutrition 21(2): 321-328;

Summers, C.G., Stapleton, J. J., (2002). Use of UV reflective mulch to delay the colonization and reduce severity of Bemisia argentifoli (Homoptcra: Aleyrodidae) infestations in cucurbits, Crop Protection 21: 921-928;

Van der Westhuizen, J.H., (1980). The effect of Black Plastic Mulch on Growth, Production and Root Development of Chenin blanc Vines under dryland conditions. South Africa Journal of Enology and Viticulture 1(1): 1-6;

Zhang, C.E., Han, J.H., Kim, G.N., (2008). Biodegradable mulch film made of starch-coated paper and its effectiveness on temperature and moisture content of soil. Commun Soil Sci Plant Anal 39: 1026-1040;

Agrobiofilm project receive funding from the European Union’s Seventh Framework Programme managed by REA – Research Executive Agency http://ec.europa.eu/research/rea(FP7/2007-2013) under the grant agreement number 262257.

This Handbook evaluates the data produced by the project and includes valuable information about the use of biodegradable mulch films. Major sections of this publication deal with the evolution of films from PE to biodegradable, project description, the use of Agrobiofilm® in various crops, biodegradation tests and timings.

compostable films for agriculture - agrobiofilm

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