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WORKING MATERIAL

Integrated Soil, Water and Nutrient Management for Conservation Agriculture

Report of the first Research Co-ordination Meeting of the Joint FAO/IAEA Co-ordinated Research Project

Vienna, Austria 13-17 June 2005

Reproduced by the IAEA Vienna, Austria, 2006

NOTE The material in this document has been agreed by the participants and has not been edited by the IAEA. The views expressed remain the responsibility of the participants and do not necessarily reflect those of the government(s) of the designating Member State(s). In particular, neither the IAEA nor any other organization or body sponsoring this meeting can be held responsible for any material reproduced in the document.

JOINT FAO/IAEA DIVISION

OF NUCLEAR TECHNIQUES IN FOOD AND AGRICULTURE

INTERNATIONAL ATOMIC ENERGY AGENCY FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS

Integrated Soil, Water and Nutrient Management

for Conservation Agriculture Report of the First Research Coordination Meeting of the Joint FAO/IAEA Coordinated Research

Project, Vienna, Austria 13-17 June 2005

IAEA-311-D1-RC-974.1

Working Material Produced by the IAEA Vienna, Austria

2006

EDITORIAL NOTE In preparing this publication for press, staff of the IAEA have made up the pages from the original manuscripts as submitted by the authors. The views expressed do not necessarily reflect those of the governments of the nominating Members States or of the nominating organizations. Throughout the text names of Member States are retained as they were when the text was compiled. The use of particular designations of countries or territories does not imply any judgment by the publisher, the IAEA, as to the legal status of such countries or territories, of their authorities and institutions or of the delimitation of their boundaries. The mention of names of specific companies or products (whether or not indicated as registered) does not imply any intention to infringe proprietary rights, nor should it be construed as an endorsement or recommendation on the part of the IAEA. The authors are responsible for having obtained the necessary permission for the IAEA to reproduce, translate or use materials from sources already protected by copyrights.

TABLE OF CONTENT

1. Introduction................................................................................................................................... 1 2. First Research Co-ordination Meeting .......................................................................................... 1 3. Technical issues related to the CRP.............................................................................................. 2

3.1 Isotope techniques used in the CRP.................................................................................... 2 3.2 Specific issues raised during the RCM............................................................................... 5

4. Needs for analytical support from Seibersdorf ............................................................................. 5 5. Conclusions................................................................................................................................... 5 Annex 1 – List of participants to the RCM ............................................................................................. 7 Annex 2 – Programme of the RCM......................................................................................................... 9 Annex 3 – Abstracts of the participants’ reports ................................................................................... 13 Annex 4 – Fractionation of organic matter by particle size .................................................................. 25 Annex 5 – Soil moisture monitoring ..................................................................................................... 27 Annex 6 – Biological N fixation measured by the 15N isotope dilution method................................... 29 Annex 7 – Project’s Document ............................................................................................................. 31

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1. Introduction The Co-ordinated Research Project (CRP) D1.50.09 on “Integrated soil, water and nutrient management for conservation agriculture” was initiated following the recommendation of a consultant meeting held in Brazil, in 2003, with an expected duration of five years (2005-2009). Conservation Agriculture (CA) shows considerable potential benefits related to increased productivity and sustainability of agricultural production systems as well as significant off-farm environmental benefits. However, there is a lack of scientific information on the impact of the introduction of CA on soil quality – nutrient – water interactions and how these interactions can influence soil organic matter dynamics, plant nutrient uptake and crop productivity. Thus, research is required to develop CA management practices that are adapted to local needs and conditions. The objective of this CRP is thus to quantify the individual and interactive effects of conservation tillage practices, residue management, crop rotations, nutrient and water inputs to increase soil organic matter, resource use efficiency, agricultural productivity and environmental quality. At the conclusion of the CRP, it is expected that:

a) new and innovative data on carbon, water and nutrient dynamics under conservation agriculture in diverse agroecosystems will have been generated;

b) means to extrapolate experimental findings across and between regions will have been defined;

c) enhanced capacity to conduct integrated soil, water and nutrient management studies with the aid of nuclear and related techniques will have been developed;

2. First Research Co-ordination Meeting The first Research Co-ordination Meeting (RCM) was held at IAEA, Vienna, Austria, from 13 to 17 June 2005. Currently, eight research contract holders: S. Lopez (Argentina), R. Boddey (Brazil), M. Aulakh (India), M. Ismaili (Morocco), W. Mohammad (Pakistan), M. Halitligil (Turkey), K. Kaizzi (Uganda), N. Ibragimov (Uzbekistan), two technical contract holders: E. Zagal (Chile) and R. Dalal (Australia) and one research agreement holder: B. Vanlauwe (Kenya) are participating to the project. All attended

Participants to the first RCM of CRP D1.50.09

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this first RCM, along with staff members from the Soil and Water Management and Crop Nutrition Section and the Soil Science Unit. The list of participants appears in Annex 1.

The programme of the Meeting (Annex 2) included four days of discussion at the IAEA Headquarters and a one-day visit at the Soil Science Unit (SSU), in Seibersdorf. The objectives of the RCM were :

a) each individual researcher presents its research objectives and plan; b) these objectives and plan are discussed; c) following a) and b), individual plans are updated by specifying:

� research topics � work plan and activities timetable � support required from IAEA

d) a visit is made at SSU’s laboratory (Seibersdorf) to explain: � the expertise and support available � the applications of nuclear techniques in different aspects of CA

The abstract of the participants’ reports are presented in Annex 3. The overall project work plan and schedule of activities as envisaged in the project document

were reviewed and updated in accordance with individual work plans and related practical considerations. Finally, conclusions and recommendations were drafted, presented and adopted. 3. Technical issues related to the CRP 3.1 Isotope techniques used in the CRP CA systems are expected to improve soil fertility (physical and nutritional), organic matter build-up, reduce soil compaction and enhance soil exchange capacity, water infiltration and water holding capacity, soil biodiversity, resilience to climate change and greenhouse gas mitigation, etc..

However, there is a gap of information on the processes involved in these impacts. The main objective of this CRP is therefore to address this lack of basic information through the research projects being implemented by the participating researchers.

These projects involve the use of several isotope techniques: • 13C and 15N to quantify the stabilization and turnover of SOM • 13C and 15N to quantify the fate of N and C in crop residues • 15N to quantify legume BNF inputs to crop rotations • 32P to study the availability and sorption of P in P-fixing soils (laboratory studies) • Neutron probe to profile soil water content • Sealed source (63Ni) to quantify N2O emissions by ECD

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From the submitted research proposals and the activity reports presented during the RCM, a synthesis of the treatments involved in the individual research work plans was prepared. The following table reports the treatments to be implemented, the parameters that will be measured under these treatments and the isotope technique that will be used. Country Title Treatments Parameters Nuclear/isotope

technique Argentina Increase of agricultural

productivity and reduction of environmental effects under no-tillage systems in Argentina

Experimental plots, farmers’ fields, rotations legume-cereal, conventional, reduced and no tillage

N, P and organic matter dynamics; biological N fixation, water balance

15N, 32P, neutron probe

Australia Water and nitrogen use efficiency in a long-term no-till cropping experiment

Experimental plots, wheat with/without rotations; conventional and no tillage; residues left or burned, N rates

Water and nutrient use efficiency, C and N dynamics, N2O emissions

13C, 15N

Brazil Carbon sequestration in soils under zero-tillage: the question of N balance

Experimental plots, farmers’ fields, long-term soybean based rotations, conventional and no tillage

C and N stock in soil profile, C dynamics, N balance, biological N fixation, N leaching (NO3) and gaseous emissions (N2O)

13C, 15N, time domain reflectometry

Chile Using maize as a reference plant material and natural 13C for field essays of soil organic carbon dynamics

Experimental plots, wheat-oat rotation, conventional and no tillage, fertilizer treatments (N and P levels)

C, N and organic matter dynamics

13C

India Integrated soil, water and nutrient management for conservation agriculture

Experimental plots, soybean-wheat/rapeseed rotations, tillage (conventional, conservation), with and without residue, fertilizer rates (100, 125% recommended)

Water, N and P use efficiency, micronutrients, organic matter dynamics, N2O losses

15N, neutron probe

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Kenya Managing nutrients, water, carbon, and belowground biodiversity in farming systems based on the principles of conservation agriculture in sub-Saharan Africa and Central America

Farmers’ fields, cereal-legumes rotations, tillage (conventional, no-tillage), residues management(kept or removed)

Water and N use efficiency, C dynamics, below-ground biodiversity

15N, 13C

Morocco Integrated soil, water and nutrient management for Conservation Agriculture in continuous wheat and legume-wheat rotations in the centre and south Morocco

Experimental plots, rotations (wheat-wheat; wheat-legume), with and without tillage, with and without residue

Water, N and P use efficiency, biological N fixation, organic matter dynamics

13C, 15N, neutron probe

Pakistan Integrated management of soil, water and nutrient for improving crop productivity, soil fertility, water use efficiency and environmental protection in rainfed areas of the North-West Frontier Province

Experimental plots, rotation (cereal-cereal/legume), conventional or no tillage, residues left or removed

Water use efficiency, N and C dynamics, biological N fixation

15N, neutron probe

Turkey Comparison of soil organic matter accumulations under various soil management systems in vetch-wheat versus wheat-wheat rotations in Central Anatolia using nuclear techniques

Experimental plots, rotations (wheat-wheat/vetch), conventional or no tillage, with or without irrigation, N fertilization levels

Water and N use efficiency, C dynamics, biological N fixation

15N, 13C, neutron probe

Uganda The potential benefit of conservation agriculture in improving soil productivity, nitrogen and water dynamics and crop yield in the farming system of eastern Uganda

Experimental plots, rotations (maize with and without legume cover crop, tillage (conventional, conservation)

Water and N use efficiency and balance, biological N fixation

15N, time domain reflectometry

Uzbekistan Conservation agriculture for wheat and cotton production in Uzbekistan

Experimental plots, rotations (wheat/mungbean-cotton), tillage (conventional, sweep, chisel and zero); with and without residues

Water balance, water and N use efficiency

15N, neutron probe

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3.2 Specific issues raised during the RCM During the RCM, three technical issues were discussed more specifically, since they have to be implemented in many individual projects. These topics of particular interest are:

a) fractionation of soil organic matter b) monitoring of soil moisture c) requirements for 15N field work

The discussions were related to minimal requirements that should be observed by all the participants measuring these parameters, so the measurements are made on similar basis and the results can be compared. These topics were discussed throughout the meeting, and some additional information was obtained during the visit of the laboratories to the Soil Science Unit in Seibersdorf. As agreed at the meeting, annexes 4, 5 and 6 provide background information on these three topics, as well as minimal requirements that should be followed by the participants involved in such measurements. 4. Needs for analytical support from Seibersdorf Some participants will require analytical services from Seibersdorf. The following table provides details on the number and nature of samples that will be sent for isotope analyses. The isotopes of interest are also identified. Country Number and nature of samples Isotopes Argentina 27, soil

18, plant 15N 15N

Australia 92, plant (anthesis) 92, crop residue 92, grain

13C, 15N 13C, 15N 13C, 15N

Chile 100, soil 10, plant

13C, 15N 13C, 15N

Morocco 150, plant 10, plant

15N 13C

Pakistan 112, plant (grain and straw) 15N Turkey 198, soil 13C Uganda 81, plant

81, soil 15N 15N

5. Conclusions The first RCM of this CRP was successfully held. The participating researchers had the opportunity to present and discuss their work plan and to share experience in the use of the different techniques and approaches involved in their research projects on Conservation Agriculture.

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The visit to the Soil Science Unit in Seibersdorf, provided participants with the opportunity to learn more about the use of nuclear techniques (stable isotopes, fallout radionuclides, neutron probes) for investigating different soil-water issues. Following the discussions that took place during the meeting, the project document was very slightly modified. It is presented in annex 7. At Dr Ismaili’s invitation, the second RCM will be held in Rabat, Morocco, on 11-15 September 2006.

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Annex 1 – List of participants to the RCM Silvia Concepción López Comisión Nacional de Energía Atómica Grupo Agronómico-Unidad de Actividad Aplicaciones Tecnológicas y Agropecuarias Avda. Del Libertador 8250 1429 - Buenos Aires – Argentina Tel: 54 1167798203 Fax: 54 1167798540 E-mail: siclopez@cae.cnea.gov.ar

ARG-12976

Ram Dalal Natural Resource Sciences Department of Natural Resources, Mines and Energy 80 Meiers Road, Indooroopilly Queensland 4068 Australia Tel: 61 738969895 Fax: 61 738969591 E-mail: Ram.Dalal@nrm.qld.gov.au

AUL-12977

Robert Michael Boddey Embrapa Agrobiologia, Km 47, Estrada Antiga Rio - São Paulo Seropédica CEP: 23890-000, Seropédica Rio de Janeiro – Brazil Tel: 55 2126821500 Fax: 55 2126821230 E-mail: bob@cnpab.embrapa.br

BRA-12978

Erick Zagal Universidad de Concepción Faculty of Agronomy Dept. of Soil Science Avenida Vicente Méndez 595 P.O. Box 537 Chillán – Chile Tel: 56 42208886 Fax: 56 42270674 E-mail: ezagal@udec.cl

CHI-12979

Milkha Aulakh Department of Soils, Punjab Agricultural University, Ludhiana 141004, Punjab India Tel: 91 1612401961 Ext 317 Fax: 91 1612400945 E-mail: msaulakh@satyam.net.in

IND-12980

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Bernard Vanlauwe Tropical Soil Biology and Fertility Institute of CIAT (TSBF) P.O. Box 30677, Nairobi Kenya Tel: 254 20524755 Fax: 254 20524763 E-mail: b.vanlauwe@cgiar.org

KEN-12981

Mohammed Ismaili Faculté des Sciences Departement de Biologie Laboratoire des Sciences du Sol BP 4010 BeniMhamed Meknes – Morocco Tel: 212 64551201 Fax: 212 55536808 E-mail: ismaili@fsmek.ac.ma

MOR-12982

Wisal Mohammad Nuclear Institute for Food and Agriculture (NIFA), Tarnab P.O. Box 446, Peshawar Pakistan Tel: 92 0912964060 Fax: 92 0912964059 E-mail: nifa@pes.comsats.net.pk

PAK-12983

Mahmut Basri Halitligil Ankara Nuclear Research Center for Agricultural and Animal Sciences (ANRCAAS) Istanbul youlu 30 cu km Saray-Ankara – Turkey Tel: 90 3128154308 Fax: 90 3128154307 E-mail: basri@taek.gov.tr

TUR-12984

Kayuki Kaizzi Kawanda Agricultural Research Institute (KARI) Soils and Soil Fertility Management Programme P.O. Box 7065 Kampala – Uganda Tel: 256 41567696 Fax: 256 41567649 E-mail: landuse@infocom.co.ug

UGA-12985

Nazirbay Ibragimov Uzbekistan National Cotton Growing Research Institute (UNCGRI) Soil Fertility Department 702133 P.O. Akkavak, Kibray District Tashkent Province, Uzbekistan Tel: 998 712642045 Fax: 998 711394993 E-mail: nazar@tkt.uz

UZB-12986

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Annex 2 – Programme of the RCM

Monday, 13 June 2005 09:00-10:00 Opening Session, Chairperson: C. Bernard, CRP Scientific Secretary Welcome address: L. Nguyen, Section Head, Soil and Water

Management & Crop Nutrition Section (SWMCN) General information on Research Contract Administration: T. Benson,

Head, NACA Introduction of participants Objectives of the meeting: C. Bernard, SWMCN 10:00-10:30 Coffee/Tea Break - Group Photo Session 1: Presentations from Participants (30 minutes each + 15 minutes for

discussion) Chairperson: R. Serraj, SWMCN

10:30-11:15 S. Lopez (Argentina): Increase of agricultural productivity and reduction of environmental effects under no-tillage systems in Argentina - Description of Argentinean situation and planned research activities.

11:15-12:00 D. Ram (Australia): Water and nitrogen use efficiency in no-till cropping and fertility restoration experiments

12:00-12:30 Discussion on papers of the morning 12:30-14:00 Lunch break Session 2: Presentations from Participants (con’td.) Chairperson: G. Hardarson, Soil Science Unit, IAEA Laboratory,

Seibersdorf 14:00-14:45 R. Boddey (Brazil): Carbon sequestration in soils under zero-tillage:

the question of N balance 14:45-15:30 E. Zagal (Chile): Using maize as reference plant material and natural

13C for field essays of soil organic carbon dynamics 15:30-16:00 Coffee/Tea Break 16:00-16:45 M. Aulakh (India): Integrated soil, water and nutrient management for

conservation agriculture 16:45-17:15 Discussion on papers of the afternoon 18:00 Welcome cocktail

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Tuesday, 14 June 2005 Session 3: Presentations from Participants (con’td.)

Chairperson: L. Mabit, SSU 09:00-09:45 M. Ismaili (Morocco): Integrated soil, water and nutrient management

for conservation agriculture in continuous wheat and legume-wheat rotation in the centre and South Morocco.

09:45-10:30 W. Mohammad (Pakistan): Integrated management of soil, water and nutrient for improving crop productivity, soil fertility, water use efficiency and environmental protection in rainfed areas of North West Frontier Province.

10:30-11:00 Coffee/Tea Break 11:00-11:45 M. Halitligil (Turkey): Comparison of soil organic matter

accumulations under various soil management systems in vetch-wheat versus wheat-wheat rotations in Central Anatolia using nuclear technique.

11:45-12:15 Discussion on papers of the morning 12:15-14:00 Lunch break Session 4: Presentations from Participants (con’td.)

Chairperson: E. Zagal, Chile 14:00-14:45 C. Kaizzi (Uganda): The potential benefit of conservation agriculture in

improving soil productivity, nitrogen and water dynamics, and crop yield in the farming system of eastern Uganda.

14:45-15:30 N. Ibragimov (Uzbekistan): Investigation of various soil tillage systems with emphasis to crop nitrogen and water use in Uzbekistan.

15:30-16:00 Coffee/Tea Break 16:00-16:30 Discussion on papers of the afternoon 16:30-17:30 Synthesis of the presentations: C. Bernard, SWMCN Wednesday, 15 June 2005 Session 5: Work planning

Chairperson: M. Ismaili, Morocco 09:00-09:30 Guidelines for the formulation of work plans: C. Bernard, SWMCN 09:30-12:00 Preparation of work plans for each participating country in line with the

project objectives 12:00-13:30 Lunch break

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Session 6: Work planning (con’td.) Chairperson: L. Heng, SSU

13:30-14:15 B. Vanlauwe (Kenya): Managing nutrients, water, carbon, and belowground biodiversity in farming systems based on the principles of conservation agriculture in sub-Saharan Africa and Central America

14:15-15:30 Presentation and Discussion of individual work plans (10 min each + 5 min discussion)

15:30-16:00 Coffee/Tea Break 16:00-17:30 Presentation and Discussion of individual work plans

(continued) Thursday, 16 June 2005 Visit to Seibersdorf Soil Laboratory - Analytical services available.

Requirements for sample processing. Cost recovery policy. Visit of laboratories. Informal discussion of project objectives and research strategy

Session 7: Isotope techniques and approaches in Conservation Agriculture Chairperson: C. Bernard, SWMCN

09:00-09:15 E. Busch-Petersen (Head, Agriculture and Biotechnology Laboratory): Welcome word.

09:15-09:45 G. Hardarson (SSU): Supportive work of the Soil Science Unit to CRPs 09:45-11:15 L. Mayr (SSU): Sample preparation and 13C analyses by mass

spectrometry M. Heiling (SSU): 13C analyses by FanCi

11:15-12:00 M. Aigner (SSU): External Quality Assurance 12:00-13:00 Lunch break 13:00-14:30 L. Heng and J.L. Arrillaga (SSU): Soil water measurements using

neutron probe and related techniques 14:30-15:15 L. Mabit (SSU): Estimation of soil erosion with gamma isotopes 15:15-15:45 General discussion on isotope techniques in Conservation Agriculture 16:00 Return to Vienna Friday, 17 June 2005 Session 8: Work planning (con’td.)

Chairperson: C. Bernard, SWMCN 08:30-10:00 Formulation of CRP work plan in accordance with project main

objectives and individual work plan

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10:00-10:30 Coffee/Tea Break 10:30-11:30 Discussion of project work plan and logical framework 11:30-12:30 Summary report of the meeting. Closing remarks 12:30 Lunch Break

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Annex 3 – Abstracts of the participants’ reports

Increase of agricultural productivity and reduction of environmental effects under no-tillage systems in Argentina- Description of Argentinean situation and planned research activities López, Silvia C. Grupo Agronómico, Comisión Nacional de Energía Atómic, Buenos Aires, Argentina No-tillage systems have widely been adopted in Argentina. Benefits on soil organic matter and physical properties recovery have been reported by different authors. Nevertheless, no-till adoption, besides other technologic advances and socio-economic reality, allowed the inclusion of more crops in the same period of time. The pasture-grain crop rotation was changed and the introduction of soy-bean in almost all crop rotation is nowadays in advance. In spite fertilization is also increasing, negative balances for N and P have been reported in rotations such as wheat-maize-soybean and wheat-maize-sunflower. Some of the pesticides and herbicides (e.g. atrazine) used in no-till would also cause adverse effects on environment. Availability of water in the profile of soil is other limitation to the adoption of adequate crop rotations. The effect of timing and amount of fertilization on grain yield is greatly related to water in soil profile provided by rainfall which is quite variable from year to year in the Pampas region. Contribution of biological fixation of N by soybean has been estimated by conventional methods in 30 to 70 % of soy-bean requirements, but little information about this contribution has been confirmed using tracers. Fertilization effects on wheat and maize crops under conventional and no-till systems have already been studied by tracer methods in our Institute. The direct use of N fertilizer has been estimated in 30 to 50% of the applied urea. The fertilizer not used would be incorporated to soil-N pool, lixiviated or loss from the soil-plant system. Balance of nutrients and water considering a complete crop rotation has not been evaluated using nuclear techniques yet. We are proposing a research project to study nutrient and water balance in crop rotations under different tillage systems, using nuclear techniques as tracer methodologies and neutron probe. Two approaches are being considered : a) a field experience where nutrient balance, water availability, 15N-fertilizer use, contribution of biological fixation of N, N fate, and matter organic dynamic will be measured during at least two years crops under conventional, reduced and zero-tillage; and, b) measurement of soil properties such as nutrient availability, matter organic content, labile organic matter, P fixing capacity, etc. in soil samples taken up in a farmer’s field with two different crop rotation under no-tillage system. In that way we expect to obtain direct data from farmer’s crop production fields and from experimental field experiences. The research team is conformed by researches from our Institute (CNEA), Universities and farmer’s consultants. Water and nitrogen use efficiency in no-till cropping and fertility restoration experiments Ram Dalal1, A. J. King1, Wayne Strong2, John Cooper2 1Department of Natural Resources and Mine 2Department of Primary Industries and Fisheries No-till (NT) cropping or conservation agriculture embodies the principles of (a) elimination of soil tillage, and (b) crop residue retention to provide soil cover. The NT practice was primarily aimed at reducing soil erosion due to water and/or wind, thus conserving the soil. Soil cover provided by crop

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residue retention potentially reduces soil erosion by as much as 95%. NT and crop residue retention also increase plant available water in arid and semi-arid rainfed agriculture, and may lead to enhanced water use efficiency (WUE) by crops. Loss of the topsoil due to erosion also leads to decline in soil fertility since the topsoil layer is more enriched in nutrients, especially the eroded sediments than the subsoil layers (Rose and Dalal 1988). Therefore, NT practice and crop residue retention may retard or even restore soil fertility. Restoration of fertility increases the crop production and better water use, therefore, may lead to increased water use efficiency compared to the low fertility soil. Water use efficiency (kg grain/ha/mm) is usually measured agronomically from field experiments from the crop’s grain yield and water use. Variation in the ratio of 13C/12C in photosynthate C in grain occurs due to the fixation of CO2 resulting from the differential stomatal diffusivities of 13CO2 and 12CO2 discrimination by the ribulose biphosphate carboxylase enzyme in favour of the heavier C isotope. The deviation in C isotope ratio, 13C/12C ratio, in a plant sample against a standard (Pee Dee Belemnite) is expressed as: δ13C (o/oo) = 1000 [(Rsample/Rstandard) – 1] [1] where Rsample is the 13C/12C molar ratio of the sample, Rstandard is the molar ratio of the standard. The C isotope discrimination is expressed then expressed as: ∆ = [(δs – δp)/ (1 + δp)] [2] where δs is the isotopic composition of the atmospheric CO2 and δp is the isotopic composition of the plant C. There is a negative relationship between the plant’s transpiration efficiency and ∆ and generally, a negative correlation between ∆ and WUE. The objectives of our study are (i) to measure δ13C of wheat grain samples produced under different tillage and cropping sequences, that is, different moisture regimes, (ii) to measure δ13C of wheat produced under different N treatments, resulting from fertiliser application or legume N fixation, (iii) to estimate agronomic WUE, and (iv) to utilise ∆ C isotopic discrimination in wheat grain samples to correlate with WUE. This study will utilise agronomic data from experiments conducted on the Warra site. It is located at 26o47’S, and 150o53’E, in Queensland, Australia. The soil at the site is a Vertisol (Typic Chromustert), very deep, ranging from dark greyish brown to dark brown clay, alkaline from surface to 0.6 m depth and acid below 0.9 m depth. Mean annual rainfall is 603mm. The mean maximum temperature in January is 27oC and mean minimum temperature is 12oC in July, with a mean annual temperature of 20.7oC. The data from the field experiment analysed from 12 treatments. These are 2-year rotations of: (1) lucerne (Medicago sativa cv. Trifecta)-wheat (Triticum aestivum cv. Hartog), (2) wheat - lucerne (alternate), (3) medic (Medicago scutellata cv. Sava)- wheat, (4) wheat- medic (alternate), (5) chickpea (Cicer aeritinum cv Barwon)- wheat, (6) wheat-chickpea (alternate), (7) wheat-wheat, conventional till (CT), 0 kg N/ha fertiliser, (8) wheat-wheat, CT, 25 kg N/ha fertiliser, (9) wheat-wheat, CT, 75 kg N/ha fertiliser, (10) wheat-wheat, no till (NT), 0 kg N/ha fertiliser, (11) wheat-wheat, NT, 25 kg N/ha fertiliser, (12) wheat-wheat, NT, 75 kg N/ha fertiliser. Measurements include plant available water in the soil profile (0-1.2 m depth) at sowing and harvest, soil nitrate- N in the soil profile (0-1.2 m depth) at sowing and harvest, soil C and N in the 0-0.1 m depth, grain yield, N yield, and agronomic WUE and N use efficiency. Grain samples will be analysed

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for δ13C, and C isotope discrimination (∆) from different treatments and related to WUE of wheat from different rotations with differences in water use, yield and N response. Expected results will be: (i) δ13C of wheat grain samples produced under NT and CT and different cropping sequences, (ii) δ13C of wheat produced under different N treatments, (iii) agronomic WUE, and (iv) ∆ C isotopic discrimination in wheat grain samples and correlated with WUE. The project outcomes will meet CRP objectives in that we will quantify the effects of conservation tillage practices on water use efficiency and N use efficiency, yield, and organic matter content and their interactive effects.

Carbon sequestration in soils under zero-tillage: The question of N balance R.M. Boddey, S. Urquiaga, B.J. Alves, C.P. Jantalia, L. Zotarell, A.P. Guimarães Embrapa-Agrobiologia, Rio de Janeiro, Brazil. This project was started in 2002 to study the impact of the introduction of green-manure legumes on the capacity of soils managed under conventional or zero tillage to accumulate soil carbon at several sites in southern Brazil. This region is responsible for approximately 50 % of the grain production in the country, and since the introduction of zero tillage (ZT) in the 1980s, almost 70 % of the mechanised crop production has now adopted this soil management system. In recent years, some farmers have started to introduce winter leguminous green-manures into the mainly soybean- and maize-based crop rotations initially to diversify cropping systems to avoid the build up of plant diseases and pests. However, work by the group at Embrapa Agrobiologia and other institutions has shown that where the only legume in the rotation is soybean there is little accumulation of soil C under ZT, and when leguminous green-manure legumes such as lupine and vetch are introduced very considerable gains in soil C are experienced. Owing to the very high N export in soybean grain, this crop has been shown to contribute virtually no biologically-fixed N to the soil-plant system, and this project has the overall objective relating overall N balance of the cropping systems under ZT and CT to the capacity of the soil to accumulated carbon/organic matter. An important prerequisite of the project was to accurately quantify the contribution of biological nitrogen fixation (BNF) using the 15N natural abundance technique to soybean and the other legumes. One investigation under the project has shown that different soybean/Bradyrhizobium symbioses show very different values of the 15N abundance of plant tissue when the plants are totally reliant on BNF (the ‘B’ value). Preliminary results show that the ‘B’ values of the two B. elkanii strains recommended for inoculant manufacture in Brazil have considerably lower ‘B’ values than the two recommended B. japonicum strains and the effect of Bradyrhizobium strain seems more important than the soybean variety. Experiments at two sites in the state of Rio Grande do Sul, confirm earlier work that: a) That the use of ZT as opposed to (CT) does not favour soil C accumulation in crop rotations where soybean is the only legume in the rotation.

b) Where winter green-manure legumes are introduced into the rotations soil C stocks under ZT are far higher than under CT.

c) Between 40 and 60 % of the extra soil C observed under ZT compared to CT for these rotations containing green-manure legumes is found at depths greater than 30 cm.

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Vetch was shown to obtain up to 70 % of its N from BNF and contribute up to 100 kg N ha-1. Lupines show similar proportions of N derived from BNF but have a higher biomass production, such that overall BNF contributions to the cropping systems can be as high as 120 kg N ha-1. Studies have been conducted, but the results are not yet available for presentation, to assess the impact of ZT versus CT and different crop rotations on the fluxes to the atmosphere of nitrous oxide. It is planned to start in the next year work on estimating leaching losses of N from the different systems under CT and ZT, and of ammonia volatilisation where N fertiliser has been added (e.g. for maize and wheat) and during the decomposition of N rich legume residues. With these data it is expected to make improved estimates of N balance to the different cropping systems and assess the importance of this parameter on the capacity of soil to accumulated organic carbon.

Using maize as a reference plant material and naturalo 13C for field assays of soil carbon dynamics. E. Zagal1, I. Vidal1, J. Balesdent2, A. Martensson3 1University of Concepción, Faculty of Agronomy, Department of Soil Science,Chillan, Chile. 2Commissariat à l’Energie Atomique, Cadarache, France. 3Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden Preventing soil degradation should be a central goal of sustainable agriculture, especially in regions under intensification or colonization of new lands. The maintenance of sufficient organic carbon content in the soil superficial layers is one of the major ways to prevent soil degradation. Organic carbon may act directly by improving the physical properties of the superficial layer, thus reducing soil erosion or conserving/improving soil structure and indirectly by increasing the biological, physical and chemical fertility. The enhancement of plant growth therefore increases soil C in a positive feedback process. The management of crop residues (above- and below-ground parts) is the major way of controlling soil C. The management by farmers can basically concern the return of residues or not (combustion, exportation, transport), the amount added, and the way and depth they are incorporated by various tillage practices. For instance reduced tillage is reported to increase soil C to various extends, especially in the uppermost soil layer, which is the most sensitive to degradation. While soil carbon dynamics and the fate of plant residues and is well documented in some countries and crop productions, there is still a need for references under many climates, soil types and land uses. To better predict the effect of the practices of C management over a wide range of situations, specific long term experiments would be required. Unfortunately, such trials cannot be implemented at each place, and would need long durations and high sensitivity, because of the dilution of added C into the existing organic matter. The isotope labeling of carbon inputs is the best tool to quantify and forecast the fate of C. This is the conventional interest of tracers to investigate systems under dynamic regimes. The natural 13C labeling technique has proven to be a very powerful tool to quantify soil organic matter dynamics and trace C inputs. It is based on the natural difference in 13C/12C ratio between C4 plants and C3 plants. The change of vegetation from one type to the other provides a natural labeling of new carbon incorporated into the soil by the vegetation. The dynamics of soil C can be there measured by the analysis of 13C/12C in soil organic matter. The latter is determined by high-resolution stable isotope ratio mass spectrometry. The method may be applied to the analysis of total soil C, but also to organic separates to decipher processes of C transformation and to analyze relevant compartments of soil organic matter. The method is very powerful but unfortunately limited to places where vegetation has changed from the C3 to the C4 type.

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We propose here to apply the natural 13C technique in any place where production are dominated by C3 plants, by applying C4 plant material and following its fate by 13C/12C measurements, in simple controlled field experiments, as a complementary tool of soil studies. The objectives of the project are:

a) to promote the use of the natural 13C labeling method to measure soil carbon dynamics in crop/grass/forest systems. This would be done without change of the vegetation, by applying in the field naturally 13C-rich plant material. The technique is intended to research teams having their own field experiments on soil organic matter, as a complementary method,

b) to promote the use of locally-produced maize shoots as a reference material. Being used by different experiments in a common frame-protocol, it could provide comparable and valuable information between sites,

c) to propose a typical frame protocol for field experiment design, analysis and calculations, which could be used for the specific question raised by each interested research team.

As additional information, labile organic matter determinations (soil biomass, C mineralization, light fraction, dissolved organic matter) can be performed according to current techniques developed e.g. soil microbial biomass by fumigation extraction, C mineralization by determination of CO2 evolution, light fraction by density and physical fractionation, dissolved organic matter by extraction in water. Integrated soil, water and nutrient management for conservation agriculture M.S. Aulakh, J.S. Manchanda t Department of Soils, Punjab Agricultural University, Ludhiana, Punjab, India In many parts of the world including South and Asia, large amounts of crop residues are burnt after crop harvest. It results not only in loss of organic matter and nutrients but also causes atmospheric pollution due to the emission of toxic and greenhouse gases like CO, CO2 and CH4 that pose a serious threat to human and ecosystem health. In India alone more than 100 Tg of crop residues are disposed of by burning each year. Burning is preferred by farmers to ensure a quick seedbed preparation and to avoid any risk of reduced crop yields associated with the incorporation of residues with wider C:N ratio that immobilize N during decomposition. No-Tillage (NT) and Conservation Agriculture (CA) practices by retaining crop residues have extensively been used for the past many decades to raise several crops in North America, Latin America, Europe and Australia and have promised several economic and environmental advantages. However, CA management systems are presently not in vogue in South Asia. At present, annual rice–wheat double-crop system occupies 26 million ha in South and East Asia and accounts for nearly one-fourth of the region’s food grain production. Major features of rice-wheat agriculture in north-western India (Punjab, Haryana, and western Uttar Pradesh) are transplanted rice on puddled soil, combine-harvesting of rice, removal or burning of rice residues followed by conventionally tilled wheat, under assured irrigated conditions. The cropping intensity in these irrigated areas is almost 200%. However, intensive tillage and use of large amounts of fertilizers have triggered off ecological degradation. Low and declining organic matter is the typical feature of these soils. Organic matter is important for the supply of N, P and S through mineralization and the retention of some micronutrient elements, enhanced cation exchange capacity, favourable water relations, and aggregate stability.

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Recent studies have demonstrated that in summer-grown flooded rice in subtropical region significant N losses occur via nitrate leaching and denitrification leading to nitrate contamination of groundwater and emission of nitrous oxide, a radiatively active trace gas that adversely affects the chemistry of the atmosphere and contributes to global warming. Furthermore, continuous pumping of groundwater over the years to meet the high water requirement of flooded rice crop has resulted in a drastic decline in groundwater table. These detrimental factors have given impetus to pursuit for alternative crops and cropping systems, which are environment-friendly and efficient in utilizing natural resources. Soybean could meet most of its N requirement by biologically fixed N and has significantly less irrigation water requirement than rice. Therefore, it could replace considerable area presently under rice crop if efficient production technology becomes available. Advent of improved mosaic-resistant cultivars of soybean have registered a substantial increase in area under soybean cultivation, especially in rotation with other crops such as wheat, rapeseed and mustard under irrigated conditions in the subtropical region. There is a lack of comprehensive information on the use of these production techniques for improved nutrient and water use efficiencies, and productivity and sustainability of these cropping systems. Continuous application of fertilizer P at high rates may also result in P-induced Zn deficiency. Therefore, studies are urgently needed to address these problems by (a) adopting conservation tillage while retaining crop residues, (b) including N2-fixing grain legume soybean and oilseed crops such as rapeseed, and (c) investigating C, N, P and micronutrients (especially Zn) dynamics as well as water conservation and availability to crops. The overall objective of the proposed project will be to enhance the productivity and sustainability of farming systems through a better understanding of the principles and practices of conservation agriculture. The specific research objective is to quantify the individual and interactive effects of conservation tillage practices, residue management, crop rotations, nutrient and water inputs to increase soil organic matter, resource use efficiency, agricultural productivity and environmental quality. To achieve these objectives, the feasibility of alternative tillage and residue management systems in relation to crop productivity and input use-efficiency (energy, nutrient and water use efficiencies) in soybean-wheat, and soybean-rapeseed cropping systems will be assessed by employing nuclear and traditional techniques. Managing nutrients, water, carbon, and belowground biodiversity in farming systems based on the principles of conservation agriculture in sub-Saharan Africa and Central America B. Vanlauwe1, A. Bationo1, N. Sanginga1, E. Amezquita2, D. Mugendi3, J. Aune4, J. Diels5 1Tropical Soil Biology and Fertility Institute of the International Centre for Tropical Agriculture (TSBF-CIAT), Nairobi, Kenya 2TSBF-CIAT, Cali, Colombia. 3Kenyatta University, Nairobi, Kenya. 4Department of International Environment and Development Studies, Noragric, Norwegian University of Life Sciences, Aas, Norway 5International Institute of Tropical Agriculture, Croydon, UK. TSBF-CIAT is dedicated to generating scientific knowledge on soil biological processes, translating this knowledge into practical land-management strategies, and empowering farmers through participatory technology development. Its principle objectives are (i) to support the livelihoods of people reliant on agriculture by developing profitable, socially-acceptable and resilient agricultural production systems based on Integrated Soil Fertility Management (ISFM), (ii) to develop Sustainable Land Management in tropical areas through reversing land degradation, and (iii) to build the human

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and social capital of all TSBF-CIAT stakeholders for research and management on the sustainable use of tropical soils. Conservation agriculture (CA) aims at improving land use management through simultaneous application of three principles: minimal soil physical disturbance, continuous soil cover, and good rotations. These principles are in complete agreement with the principles underlying ISFM - although the latter puts less emphasis on physical management of the soil - and are thus central to the goals and objectives of TSBF-CIAT. Within above context, specific research topics to be addressed are (i) exploration of interactions between nutrients and water, (ii) quantification of soil organic C dynamics, (iii) understanding of rotational effects in legume-cereal rotations, and (iv) evaluation of belowground biodiversity. Above issues will be addressed using a variety of currently accepted approaches, including strategic techniques (including isotope methods), farmer-participatory tools, and methods for holistic evaluation (agronomic, economic, social) of improved land management options. Especially the introduction of improved and stress-tolerant germplasm will be used as entry points to optimize above soil properties and functions. The target farming systems are cereal-legumes-livestock system in the dryland and savannas agroecosystem of SSA and agroforestry/fallow systems in the highlands of Central America. In the later region, specific attention will be given to the widely adopted Quesungual system which is a CA system based on the management of natural tree-based vegetation. The specific research objectives are:

(i) to quantify interactions between nutrient use and water harvesting to ensure optimal use efficiency of both inputs in target farming systems in SSA and Central America.

(ii) to quantify soil organic C dynamics as affected by the quantity, quality, and management of organic inputs, including assessment of C sequestration (change in C stocks minus change in N2O gas production) in above systems.

(iii) to evaluate the diversity and abundance of functional soil biological groups in above systems. (iv) to train AfNet and MIS partners in enhancing their capacity to address the research topics

raised under specific objectives (i) to (iii). The above research agenda is mostly implemented through the TSBF-CIAT networks. These networks are the African network for Tropical Soil Biology and Fertility (AfNet), operating in Sub-Saharan Africa (SSA), and the Managing Infertile Soils Consortium (MIS), operating in Central America. Within the AfNet and MIS networks, several initiatives involving CA practices or systems are currently in various stages of implementation. Consequently, progress with each of these initiatives will be reported during the various CRP planning meetings and in the various progress reports. In an initial phase, specific attention will be given to two initiatives: (i) water x nutrient interaction trials with as factors till vs. no-till, crop residue retained vs. removed, and rotation vs. no rotation, initiated in 3 sites in SSA and (ii) Quesungual characterization work, initiated in Central America. As new initiatives are taken to address CA issues, these will be reported during later phases of the CRP. The expected results are:

(i) a clear understanding of the potential of specific CA practices/farming systems to enhance the use efficiency of water and nutrients, to store soil organic C, and to retain or enhance soil belowground biodiversity.

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(ii) scientific documents describing and summarizing all the above. (iii) enhanced capacity of AfNet and MIS partners in evaluation various relevant aspects of CA

systems.

Integrated soil, water and nutrient management for conservation agriculture in continuous wheat and legume-wheat rotation in the centre and south Morocco. I. Mohammed1, R. Mrabet2, B. Abderazzak3 1Faculty of Science, University Moulay Ismaili. 2National Research institute (INRA), Meknés. 3National School of Agriculture (ENA, Meknés) Soil organic matter is important for sustainable productivity of agro-ecosystems. Conservation agriculture is a good strategy to improve those lands and sustain their production. Trails of no tillage and reasoned use of herbicides in a legume - wheat rotation and continuous wheat are ongoing within INRA Experimental station in Settat and the experimental station of ENAM in Meknès. The soil is shallow, poor in OM and of low fertility and water holding capacity. Conservation tillage practices are a new technology in Morocco which is needed to improve crop production in arid and semi-arid areas and allow sustainability of agricultural production and enhance food security for small holders. Field studies using 15N were conducted in different climatic conditions to investigate the response of the actual system to the introduction of no tillage agriculture especially on: soil nutrients, water use efficiency, SOM dynamics, control of weeds and crop disease and the interaction between them. The results will help to develop optimal conservation agriculture (CA) management practices adapted to the cereal production in a legume wheat rotation system and give scientific basis for expansion of CA in different regions of Morocco. The impact of no tillage and rotation on soil organic matter accumulation and nutrients available in soil, the recovery of wheat residue nitrogen-15 and residual effects of N fertilization in the wheat-wheat and wheat-legume cropping systems; the effect of irrigation systems and organic and inorganic fertilizers, and synchronisation of organic matter decomposition and nutrients availability in soil are investigated. No tillage cropping have altered several soil properties at Sidi El Aydi site: higher aggregation, carbon accumulation, pH decline and particulate organic matter build up. The accumulation of soil organic matter (carbon and nitrogen) in no till surface zone without depletion at deeper horizons compared to conventional tillage. The rotation system affected the processes of organic matter accumulation and aggregation. The increase in total soil organic matter after a long period of no tillage system is important because soils in semi arid Morocco have very low organic matter content. In addition soil nitrogen loss is reduced and then more N is available to crops. The results showed that No-tillage system improve water storage; induce changes in soil quality, surface organic matter, extractable nutrients, accumulation of crop residues in surface soil, wetter and cooler and less oxidative soil environment. The fertilizer nitrogen recovery by the wheat in the first year was 33.1 %. At harvest, a high residual of fertiliser-derived N was found in the 0-80cm profile (76.2 kg N ha-1). 2.1 % of the applied N could not be accounted for and was mainly ascribed to denitrification. The recovery of the residual labelled fertiliser by the subsequent wheat crop was 6.4 % when residues were not incorporated to soil and 7.4 % when residues were added to soil. The nitrogen not recovered after second cropping season was 15.6 % and 11.8 % for the treatment without residues and the treatment with residues incorporation respectively. The loss of 15N was not due to leaching process but to denitrification. In the treatment with labelled residue incorporation, the % of the recovery by plant was 16.2% indicating the mineralization of the residues applied. The present investigations showed

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that carry-over of fertiliser N from one growing season to the next in soils cropped under the conditions of arid-Saharan Mediterranean climate is substantial. The losses of residual fertiliser N during the growing seasons were small. The addition of 8 t ha-1 of wheat residues mixed with 42 kg N ha-1 was not sufficient to have a satisfactory wheat production. Synchronization between the nitrogen liberation of the wheat residues and availability of nutrients to the wheat crop was low. These experiments will be continued with the objective to enhance the productivity and sustainability of legume-wheat and wheat-wheat systems through a better understanding of the principles and practices of CA. Our specific objectives are 1) to quantify the individual and interactive effects of conservation tillage practices, residues management and crop rotation, 2) to quantify nitrogen use efficiency, phosphorus, water use efficiency as affected by different cropping systems and no tillage practices, 3) to determine the effect of accumulation of soil organic matter on wheat, faba bean and medic productivity, 4) to quantify nitrogen fixation, nitrogen transfer in no-tillage agriculture, 5) to determine the impact of conservation agriculture on environmental quality. Nuclear techniques (15N, 32P, neutron probe, 13C) will be used. Integrated management of soil, water and nutrient for improving crop productivity, soil fertility, water use efficiency and environmental protection in rainfed areas of North-West Frontier Province W. Mohammad, S .Mahmood Shah, S. Shehzadi, S. Azam Shah, H. Nawaz Nuclear Institute for Food and Agriculture (NIFA), Tarnab, Peshawar, Pakistan Pakistan is predominantly an arid and semiarid country and Agriculture is the mainstay of country economy. It provides livelihood to 70-80% of the people living in rural areas, employs 45-50 percent of the labour force. It serves as the base for major industries. Of the total cropped area of 21.85 million ha in Pakistan, about 4 Mha are rainfed. The maximum proportion of rainfed area is in North West Frontier Province (NWFP) of Pakistan where 50% of the cropped area is rainfed. Low productivity is the common feature of rainfed agriculture because of erratic and inadequate precipitation, very low organic matter content, poor physical condition, hardpan, soils erosion and other undesirable environmental conditions like dry air and high soil temperatures. The nutrients losses in the soil from chemical fertilizers (because of their poor utilization) and their unavailability at proper time are also becoming the matters of serious concern in rainfed farming. Due to these reasons, the contribution of rainfed areas to national economy is minimal. However, great potential exist in these areas for increasing crop productivity, if appropriate integrated soil, water, nutrient and crop management system are developed for improving soil fertility, water/soil conservation and efficient utilization of these inputs. Through principles of conservation agriculture such as maintenance of a continuous soil cover through surface retention of crop residues, reduced or zero tillage and involvement of legumes in crop rotations can play an important role to sustain soil fertility, improving water use efficiency, physical conditions of soils and enhance crop productivity. In addition to crop production and soil fertility improvement, it will also help in reducing the erosion and environmental pollution. In the recent past, our research group conducted field experiments in rainfed areas to study the response of three cropping sequence to two tillage and nutrient management factors with a view to improve and sustained productivity of the rainfed farming system. Profitable cropping sequence, cultural practices with improved water use efficiency was identified by using nuclear techniques. In the proposed project, efforts will be made to explored appropriate management of crop rotations, reduced/zero tillage practice, crop residues retention on soil surface with minimum application of mineral fertilizers for conservation agriculture, with a view to improve soil fertility, water/soil conservation and efficient utilization of production inputs using nuclear techniques.

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Comparison of soil organic matter accumulations under various soil management systems in vetch-wheat versus wheat-wheat rotations in Central Anatolia using nuclear techniques M. Basri Halitligil, H. Kışlal Turkish Atomic Energy Authority Ankara Nuclear Research Center for Agriculture and Animal Sciences Soil organic matter is closely associated with soil quality. The definition of soil is linked to the effects of organisms and their residues, and it is the accumulation of organic matter that changes the deposits of sand, silt and clay into soil. Soil organic matter can be defined in terms of soil organic carbon. The amount of soil carbon and hence the changes in soil carbon can be determined by 13C technique. Soil organic matter includes oxygen, hydrogen, nitrogen, sulfur etc. in addition to carbon; therefore, if we know the amount of soil carbon we can multiply that amount with 1.7 and get the amount of soil organic matter. Cropping systems such as different tillage and crop rotations systems can change the soil organic carbon. With this research work the quantitative estimation of soil organic matter dynamics, water and nitrogen use efficiencies in wheat-wheat and vetch-wheat (where vetch is green manured at 10 % flowering stage) rotations systems will be compared by using nuclear techniques. Some specific purposes of this research work are:

� to find out influence of the soil organic matter by green manuring of vetch (mixing the green vetch in to the soil at 10 % flowering stage)in vetch-wheat rotation,

� to find out the amount of soil carbon by 13C technique at different tillage systems in vetch-wheat rotation,

� to find out the water and nitrogen use by wheat in vetch-wheat rotation and soil moisture conservation,

� to find out the effects of different irrigation and N fertilization rates to wheat yields by using neutron probe and 15N techniques,

� to find out the N2-fixation of vetch in vetch-wheat rotation. The potential benefit of conservation agriculture in improving soil productivity, nitrogen and water dynamics, and crop yield in the farming system of eastern Uganda C. Kayuki Kaizzi National Agricultural Research Organization, Kawanda Agricultural Research Institute, Kampala, Uganda. Land degradation, N and P deficiencies, soil fertility depletion, and increased loss of nutrients through erosion and surface runoff, and nutrient mining are some of the major factors causing a decline in per capita agricultural production and crop yield per unit area of production in Sub-Saharan Africa. Maintenance of soil organic matter, replenishing nutrients, reducing/controlling soil erosion and surface runoff are keys to improving and sustaining soil productivity, and maintenance of ecosystem services. Since nitrogen deficiency, and unreliable rainfall (causing early-, mid- or end- of season drought) affects crop yield, understanding both the nitrogen and water dynamics, N use efficiency, and

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the nutrient*water interactions under conservation tillage as compared to conventional tillage is essential in defining/designing sustainable farming systems. A study is conducted at Bulegeni Agricultural Research and Development Center (ARDC), Pallisa District Agricultural Training and Information Center (DATIC) and Kibale Technology Verification Center (TVC) in eastern Uganda. The sites are located in different agro-ecological zones, and have soils of different fertility status. The objectives of the study are to determine/evaluate under conservation tillage as compared to conventional tillage:

a) biological nitrogen fixation by the different legumes used as cover crops (herbaceous) or in rotation (grain),

b) nitrogen use efficiency and balance, c) the movement of NO3-N and exchangeable bases down the soil profile d) soil moisture dynamics, water x nutrient interactions.

The experimental design; main plots are - conservation agriculture (CA) and conventional tillage (CT), the sub-plots are a) farmer practice, b) Mucuna pruriens (cover crop), c) soybean, and d) inorganic-N fertilizer. The sub-plots are to be split into 2 in the subsequent seasons, with one half receiving a blanket application of 30 kg P ha-1 annually. 15N isotope will be used in the N studies, and TDR 2000 in the water studies. Analysis of soil and plant samples for 15N will be carried out at the FAO/IAEA laboratories at Seibersdorf, Vienna. The soils at the research sites have been characterized and the trials set up using mucuna and soybean. Expected results include, data on a) N input through biological nitrogen fixation, b) N use efficiency, c) water dynamics, water x nutrient interactions, d) nutrient dynamics under CA and CT and e) scientific publications. The results from the research will enhance our understanding of the contribution of conservation tillage towards the sustainability of the farming systems. Investigation of various soil tillage systems with emphasis to crop nitrogen and water use in Uzbekistan N. Ibragimov Soil Fertility Lab, Uzbekistan National Cotton Growing Research Institute Conservation agriculture practices hold important promise for the reduction of irrigation demand and the improvement of soil tilth. The effect of tillage system choice on the soil water balance under cotton, legumes, and winter wheat in Uzbekistan is not well understood. Knowledge from other regions is not directly transferable to soils and climate of Uzbekistan. Experiments in Uzbekistan have established crop water use and water balance data for irrigated winter wheat and cotton using conventional (moldboard plow) tillage, which will be used as base line data in addition to the conventional tillage treatments in each experiment. Nitrogen utilization under limited tillage and zero tillage has not been determined, although data on nitrogen utilization is available from previous experiments under conventional tillage. Further research is needed to determine the causal factors and test improved methods of zero or minimum tillage. The general objective of the project is to determine the impacts of limited and no-tillage practices on nitrogen cycling, water balance, and erosion on irrigated lands devoted to cotton and winter wheat. The specific objectives for winter wheat, mungbean and cotton include:

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a) to measure water balance, including moisture at planting, under four tillage systems (conventional moldboard plow, chiseling to 18 cm, subsurface sweep tillage [stubble mulch tillage], and zero tillage),

b) to measure crops nitrogen utilization under these four tillage systems. It is expected that if the use of permanent bed planting systems with crop residue retention can be realized, marked improvements in soil quality parameters and amelioration of soil salinity can be achieved, which will result in more efficient crop water and nitrogen use and sustainable crop production systems. The experiments will take place at the Uzbekistan National Cotton Growing Research Institute (UNCGRI) main research station at Tashkent (41’05”N, 69’30”E), and at the Syrdarya branch research station (40’50”N, 68’80”E). At Tashkent, the soil is an old irrigated typical gray soil (none saline), with water table at 15 to 18 m depth. The soil at Syrdarya is salt affected, and is a transitional gray-meadow soil, with water table at 2 to 3 m depth. The field experiment involves four treatments on soil tillage, 4 replicates in randomized block design. Split plot design: (a) crop residues will be removed as current farmer practice and (b) crop residues are retained and, if applicable, incorporated with the tillage operations. Crop rotation: 2 years winter wheat/mungbean (summer crop) + 2 years cotton. Soil physical properties (bulk density, compaction. and infiltration capacity) will be measured before planting and after harvest. Soil water balance will be measured with the neutron probe (calibrated according to Evett et al., 2002) at planting and at two-week intervals through harvest. Irrigation will be furrows and scheduled using the neutron probe to detect percentages of field capacity. 15N sub-plots (1 m • 1 m) will be established and nitrogen uptake rate by crops will be determined by analysis for 15N on plant samples (NOI 7). Phenological observations will be made monthly. Dry matter and yield will be measured by hand sampling. The project is expected to produce an evaluation of the potential of limited soil tillage and no tillage systems for winter wheat/mungbean and cotton rotation in Uzbekistan and to determine nitrogen and water use by crops under these soil tillage systems and rotations.

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Annex 4 – Fractionation of organic matter by particle size1 Principle: The objective of this procedure is to determine the absolute amounts and relative proportions of particulate organic C and N in soils. Particulate soil organic matter is defined as the fractions with diameters between 50-250 µm and is captured using the wet sieving technique. The assumption is that the particulate fraction is the SOM most readily formed and decomposed in soils and that its levels and dynamics reflect upon the sustainability of various land management options. Furthermore, the particulate fraction is an important substrate for soil mineralization processes, and a relative decline in the size of this fraction to total SOM is indicative of a loss in inherent soil fertility. Materials:

a) 2 mm, 250 µm and 50 µm soil sieves b) Wet sieving apparatus and vibrating sieve shaker c) 50 g (dry weight) fresh soil sample d) Soil dispersal agent (e.g. Na hexametaphosphate, also known as calgon)

Procedure a) Collect a fresh soil sample and determine the moisture content of a sub sample b) Assemble a wet sieving apparatus with mesh sizes 2 mm, 250 µm and 50 µm. c) Disperse a 50 g (dry weight) fresh soil sample with 10% calgon solution. Place the dispersed soil sample on the 2 mm sieve, begin wet sieving.

d) After 20 minutes, collect the fractions contained on the 2 mm sieve and between the 250 µm - 2 mm and 50-250 µm mesh sizes.

e) Examine selected samples of the 50-250 µm fraction under a microscope at 50 to 100 power to determine the relative proportions of fungal spores and mycelia, plant cellular materials and non-cellular particulate organic matter (Optional).

f) Repeat previous steps using 50 g (dry weight) of a fresh non-dispersed soil sample. g) Oven-dry the collected samples at 65 oC for 24 hours and record the weight of the samples.

h) Determine the particulate organic C and N contents of the collected materials. i) Determine the total particulate organic C and N contents of the soils.

Remarks Wet sieving of fresh soil is recommended in order to reduce changes in soil structural properties resulting from air or oven drying. The 2 mm, 250 µm and 50 µm mesh sieves are selected because the particulate organic matter (POM) of soil is defined as having diameters between 50 µm and 250 µm. The 2 mm mesh collects root litter and coarse to medium sand, the 250 µm mesh collects fine sand and partly degraded plant residues, the 50 µm mesh collects silt and POM and passes clay, soil microbes and clay associated organo-mineral complexes (humic substances). This procedure is a rapid approximation of soil organic matter fractions based on particle size only, and does not yield information on microbial biomass. Microscopic examination indicates that both microbial colonies and

___________________________________________________________________________ 1 Adapted from: Okalebo, J.R., Gathua, K.W., Woomer, P.L. 2002. Laboratory methods of soil and plant analysis: A working manual. 2nd edition. pp 81-83.

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skins of humic substances adhere to the POM fraction during sieving. Other microorganisms are fragmented, and very likely washed through to 50 µm sieve. Interpretation of results The absolute amount of POM is a reflection of the balance between plant residue inputs and the mineralization of soil organic matter. POM is believed to be a more labile fraction of SOM. Because of this, the relative proportion of POM to SOM (POMR) is a measure of the mid- to long-term balance of organic matter inputs and losses of a soil system. For example, many forest soils contain greater than 50% POM (POMR > 0.5) and following several years of cultivation and removal of harvest the POMR drops to < 0.2. The protected particulate organic matter (POMP) results from the effects of soil aggregation (particularly clays and amorphous minerals) and may represent the longer-term potential of a soil system to provide, plant nutrients. In long term plant productivity and soils studies, changes in POM are very likely to be correlated with changes in crop performance over time or due to residue management and organic input strategies. Calculations 1. The total particulate organic carbon of the

dispersed soil (POMT) is: POMT = (DW50-250) • (%C/100)

2. The unprotected particulate organic carbon of the non-dispersed soil (POMU) is:

POMU = (DW50-250) • (%C/100) 3. The particulate organic carbon that is

physically protected (POMP) by the soil aggregates is:

POMP = POMT - POMU 4. The relative proportion of particulate

organic carbon (POMR) is equal to: POMR = POMT / Total soil C

Note that similar calculation can be performed for the data obtained from the nitrogen analyses. An alternative approach is to compare the N mineralization of the particulate fraction to that of 50 g (dry weight) oven dried soil. References Cambardella. C.A., Elliott, E.T. 1992. Particulate soil organic matter across a grassland cultivation sequence. Soil Sci. Soc. Am. J. 56:777-783. Elliott, E.T., Cambardella C.A., Cole C.V. 1993. Modification of ecosystem processes by management and mediation of soil organic matter dynamics. In: K. Mulongoy & R. Merckx (eds.) Soil Organic Matter Dynamics and Sustainability of Tropical Agriculture. John Wiley & Sons, Chichester, U.K. pp 257-268.

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Annex 5 – Soil moisture monitoring1 Accurate water measurement and soil moisture monitoring are key components of efficient on-farm water management practices which can increase water-use efficiency (WUE). Water use and WUE of both irrigated and dryland crops can be measured with weighing lysimeters or with soil water balance methods using measurements of soil profile water content, as below:

ET = -∆S + P + I – R + D where ET is evapotranspiration or crop water use, ∆S is change in soil water stored in the profile, P is precipitation, I is Irrigation, R as the sum of runoff and run-on, D is deep drainage across the lower boundary of the soil profile.

If runoff, run-on (R) and deep drainage (D) can be assumed zero for the soil, the soil water balance equation can be simplified to give crop water use ET as:

ET = -∆S + P + I Values of SYZ, the root zone water content can be calculated as a depth of water by calculating the sum of volumetric water content θv at each depth multiplied by the depth of soil layer represented by that water content. For example

SYZ = θv1d1 + θv2d2 + θv3d3 where θv1, θv2 and θv3 are volumetric water contents at three soil depths representing the root zone; d1, d2, and d3 are the thickness of each of the three soil layers sampled; and SYZ has the units of d.

WUE (kg ha-1 mm-1), which is defined as dry matter production over ET can then be easily calculated. There are many ways to measure soil moisture, each method having its own advantages and disadvantages, and varying degrees of accuracy. In general, the capacitance or frequency domain (FD) probes estimate soil moisture by measuring soil electrical properties that are related to water content. They can be read immediately, but are affected by salinity, soil texture, and small-scale variability in soil moisture. Some capacitance probes can be used in an access tube, while others are made to be buried or have stainless steel probe rods that can be inserted into the soil. They need to be calibrated before use. All soil moisture sensors except the neutron probe require excellent contact with the soil and will not give accurate readings if there are air pockets near the probes or access tube walls. The neutron probe and the gravimetric method (calculating moisture as a percentage of soil weight) are the two most standard methods to obtain accurate soil moisture data. Like the capacitance sensors, the neutron probe must be calibrated for the particular soil which is to use. Access tube installation is much less critical with the neutron probe. The neutron probe however requires training in radiation safety and a license to handle the low-level radioactive neutron source. What is equally important in the measurement of soil moisture is to know the depth of measurement. This requires some knowledge of the depth of rooting of the crop, which varies widely for different crops and varies according to maturity. Some perennials like trees and vines can have roots going to ___________________________________________________________________________ 1 Contribution from Lee Heng, Soil Science Unit of Seibersdorf Laboratory

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many metres depth. Root zones of market garden crops can vary from 0.1-m to 0.5-m deep. Mature cereal crops and forage crops may extend their roots to depths from 1 to >3 m. Hence it is important that sufficient depth is being measured for the data to be useful (so that the deep drainage component need not to be estimated). For a 1.5-meter soil depth, it would be ideal to measure around 7 depths intervals at say 15, 30, 45, 60, 90, 120 and 150 cm. Equally important is that sufficient time intervals are measured, to give a better idea of the extraction pattern. In most soil moisture studies, measurements are done every ten days or two weeks, often also before and after a major rain or irrigation event. It is also important to monitor the crop development stage, leaf area index or dry matter growth. The amount and time of irrigation should be monitored. If possible, weather conditions (daily rainfall, maximum and minimum temperature and sunshine or solar radiation) should be recorded during the experimental period by automatic weather station. This will allow computer simulation of the experimental results to be carried out.

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Annex 6 – Biological N fixation measured by the 15N isotope dilution method1 The so called 15N isotope dilution method and other methods based on the same principle involves the growth of N2 fixing (F) and non-fixing reference (NF) plants in soil fertilized with 15N enriched inorganic or organic fertilisers. It relies on differential dilution in the plant of 15N-labelled fertiliser by soil and fixed nitrogen (McAuliffe et al., 1958; Fried and Broeshart, 1975; Fried and Middelboe, 1977). It provides an integrated measurement of amount of fixed N accumulated by a crop over the growing season. The uptake of 15N enriched fertiliser added to soil will result in a 15N/14N ratio greater than 0.3663% within the plant, the extent of which is a reflection of uptake of the labelled 15N fertiliser. A decrease in the atom %15N excess of the fertiliser nitrogen within the plant is an indication of the extent to which the plant took up N from other unlabelled N sources, e.g. air. For the 15N isotope dilution method, both fixing and reference plants are grown in soil to which the same amount of fertiliser having the same 15N enrichment, has been applied. Thus, in the absence of any supply of N other than soil and 15N labelled fertiliser, a fixing plant and a nonfixing reference plant will contain the same ratio of 15N/14N, since they are taking up N of the same 15N/14N composition, but not necessarily the same total quantity of N. In both plants, the 15N/14N ratio within the plant is lowered by the N absorbed from the unlabelled soil. However, in the presence of N2, and because of atmospheric N2 fixation by the fixing plant the 15N/14N ratio is lowered further. The extent to which the 15N/14N ratio in the fixing crop is decreased, relative to the non-fixing plant can be used to estimate N2 fixed in the field. The assumption made by the 15N isotope dilution methodology is that both fixing and non-fixing plants take up nitrogen from soil and fertiliser in the same ratio. For this to be true the fixing and the non-fixing crops have to meet the following conditions (Witty, 1984):

a) Either fertiliser distribution is even with depth or that the legume and reference crops have spatially similar nutrient uptake profiles, i.e. the root systems should be similar.

b) The contribution of seed N should be negligible, which is not always true especially if the plants are harvested early in the growing season.

c) It is implicit in the calculation that the enrichment of plant available soil N remains constant with time or that the legume and control have similar N uptake patterns. In practice when fertiliser N is added as a single application the enrichment of plant available soil N declines with time; and this decline can vary between the legume and the control plant. Depending on whether the control takes up soil nitrogen faster or slower than the legume, the calculated nitrogen fixation rate will be greater or less than the true value (Witty, 1983). Errors due to making this assumption may be reduced by the use of slow-release N fertiliser and by choice of a control plant which closely parallels the legume in its nitrogen uptake. (Witty, 1984).

The accuracy and precision of the isotope dilution method depends to a great extent on selecting a suitable NF reference crop. The selection of the appropriate reference plant is crucial, and it is essential to observe the following:

___________________________________________________________________________ 1 Adapted from: IAEA. 2001. Use of isotope and radiation methods in soil and water management and crop nutrition. IAEA-TCS-14. IAEA, Vienna, Austria. pp. 59-65.

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a) That the reference crop does not itself fix nitrogen. This can, if necessary, be checked very quickly, using the acetylene reduction assay.

b) The rooting depths of both reference and fixing crops should be similar, or both crops should derive all of their N from the same zone.

c) Both N2 fixing and reference crops should go through similar growth or physiological stages, and mature at about the same time.

d) Both N2 fixing and standard crops should be planted and harvested at the same time. e) Both crops should be affected in similar fashion by changes in environmental conditions, such as temperature and water, during growth period.

For estimating N2 fixed in grain legumes, the following NF reference crops have been used: a) A non-legume, non-fixing plant. b) A non-nodulating legume plant. c) An uninoculated legume plant in soils devoid of the appropriate strains of Rhizobium.

References: Fried, M., Broeshart, H. 1975. An independent measurement of the amount of nitrogen fixed by legume crops. Plant and Soil 43: 707-711. Fried, M., Middleboe, V. 1977. Measurement of amount of nitrogen fixed by a legume crop. Plant and Soil 47: 713-715. McAuliffe, C., Chamlee, D. S., Uribe-Arango, H., Woodhouse, W. W. 1958. Influence of inorganic nitrogen or nitrogen fixation by legumes as revealed by 15N. Agronomy Journal: 334-337. Witty, J. F. 1983. Estimating N2-fixation in the field using 15N-labelled fertiliser: Some problems and solutions. Soil Biology and Biochemistry 15: 631-639. Witty, J. F. 1984. The validity of some assumptions inherent in the application of the acetylene assay and the isotope dilution method. Biological N2 Fixation Newsletter 12: 1-3.

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Annex 7 – Project’s Document Title of the CRP: Integrated Soil, Water and Nutrient Management for Conservation Agriculture Background Situation Analysis (Rationale/Problem Definition): Of the total area of land in the world presently under arable crops (1,360 Mha – FAO, 2002) at least 225 Mha are estimated to be severely to moderately degraded (Oldeman, 1994). In tropical and sub-tropical regions, owing to higher soil organic matter (SOM) decomposition rates due to high temperatures, and in many regions increased pressure on the land due to population growth, this problem is disproportionately severe and growing more rapidly than in temperate regions. For example, it is estimated that 25 % of all degraded agricultural land is found in Africa. With the development of effective wide spectrum herbicides in the USA during the1960s, the first steps were made to eliminate soil tillage, and no-tillage crop production systems were developed and spread such that today 13 % of all arable crop area (22.4 Mha) in the USA is under no-till (Derpsch, 2003). In the early 1970’s, in response to severe erosion problems occurring in southern Brazil where the soil was tilled twice a year under continuous wheat/soybean cropping, progressive farmers started to experiment with no-till in this sub-tropical region. Until the 1990s the spread of this system in Brazil was modest (~1 Mha in 1992), but in order to mitigate pest and disease problems most practitioners introduced more crops into the system with maize in summer and oats or green manures in winter. From trials with these systems in Brazil and elsewhere, the various management systems, which today are collectively known as Conservation Agriculture (CA) were developed. CA depends essentially on three principal management practices: (a) Elimination or reduction of tillage, (b) year-round preservation of soil cover with crops or crop residues and (c) crop rotations including where possible contrasting crops such as cereals in rotation with N2-fixing legumes and/or Cruciferae. Today theses systems occupy over a third of the cropped area of Brazil (17.4 Mha) and over half of that in Argentina (13 Mha) and worldwide amounts to ~70 Mha (Derpsch, 2003). The benefits of the adoption of this system are unquestionable in terms of soil conservation, reduction of labour and/or fuel inputs, and other frequently observed advantages including improved soil fertility (physical and nutritional), better water infiltration, SOM accumulation, reduced soil compaction, higher CEC, better WHC, increased soil biodiversity, resilience to climate change and greenhouse gas mitigation, all of which interact in a complex way to increase agricultural productivity. There are very considerable potential benefits of CA, not only for increasing productivity and sustainability of agricultural production systems with significant off-farm environmental benefits, but also to enhance food security for millions of smallholders in the developing world. The rapid adoption of this system in South America, the USA and Australia has outpaced the scientific understanding of the principles of CA, and major efforts are being made by FAO, CGIAR centres, NARS of many countries, NGOs and CA farmer associations/federations to expand the adoption of CA. However, there is a deficit in the scientific understanding of the impact of the introduction of CA on nutrient and water use efficiency, SOM dynamics, control of weeds and crop disease and the interactions between them. It is essential that this lack of basic information be addressed through research, in order to develop optimal CA management practices adapted to local needs and conditions. This will provide a sound scientific basis for expansion of CA into regions (Europe, Central America, Africa, Asia) where it is not currently widespread.

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The Agency’s involvement is justified in that: a) Nuclear techniques are essential to obtain quantitative estimates of organic matter dynamics, water balance and nutrient flows in CA systems. More specifically, the techniques that may be used include:

• 13C and 15N to quantify the stabilization and turnover of SOM • 13C and 15N to quantify the fate of N and C in crop residues • 15N to quantify legume BNF inputs to crop rotations • Neutron probe to profile soil water content • Sealed source (63Ni) to quantify N2O emissions by ECD • 32P to study the availability and sorption of P in P-fixing soils (laboratory studies)

b) The objectives of the proposed project fall within the scope of Agency Project E.1.02 “Development of soil management and conservation practices for sustainable crop production and environmental protection” and are in line with a Major Output of the FAO’s Medium Term Plan

c) The research approaches envisaged are highly relevant to Member States of FAO and IAEA. d) The proposed CRP will operate within the framework of regional networks of national research institutes working in CA. The Agency has a strong track record in the conduct of co-ordinated research networks that have successfully brought together scientists from different disciplines in both developing and developed countries. The findings from this CRP could be further disseminated through national or Regional Technical Co-operation Projects.

e) The Seibersdorf Laboratory of IAEA has strong in-house capacity to support the CRP through training, quality assurance, analytical services, and strategic research capability.

Overall Objective: To enhance the productivity and sustainability of farming systems through a better understanding of the principles and practice of CA.

Specific Research Objective (Purpose): To quantify the individual and interactive effects of conservation tillage practices, residue management, crop rotations, nutrient and water inputs to increase soil organic matter, resource use efficiency, agricultural productivity and environmental quality

Expected Research Outputs (Results): a) Data on carbon, water and nutrient dynamics under conservation agriculture in diverse agroecosystems

b) Means (minimal common requirements, modelling) to extrapolate experimental findings across and between regions.

c) Enhanced capacity of NARS to conduct integrated soil, water and nutrient management studies with the aid of nuclear and related techniques.

d) Research findings communicated to the wider community.

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Action Plan (Activities): 1) Consultants’ Meeting (August 2003). The CM Report is attached. 2) Presentation of Project Document to PCC (October 2003) 3) Advertisement of approved CRP (December 2003) 4) Research contract and agreement proposals received (February – July 2004), evaluated (August-September 2004) and approved by PCC (October 2004). Preference will be given to scientists already conducting research in conservation agriculture so that the planned activities in the CRP can be integrated into existing experiments. Experience in the use of nuclear techniques will be required. Contract proposals will be encouraged/solicited from NARS scientists in developing countries who are part of research networks or teams being supported by FAO, the CGIAR or other international funding agencies.

5) Research Contracts (~10 @ US $8,000), and Agreements (4 - 5) awarded (Jan-Feb. 2005, R0). Research contracts and agreements renewed annually in February 2006 (R1), 2007 (R2), 2008 (R3) and 2009 (R4).

6) Research will be conducted on the impact of CA practices on productivity and the dynamics and interactions between soil carbon, water and plant nutrients.

7) Scientific Secretary of the CRP to attend the 3rd World Congress on CA (Kenya 2005) to keep abreast of latest developments.

8) RCMs: 1st in June 2005, at IAEA Headquarters, Vienna (Austria) including a training workshop at Seibersdorf Laboratories; 2nd (September 2006, in Rabat, Morocco); 3rd (March 2008, venue to be determined); 4th (Sept 2009).

9) Publications: TECDOC or special issue of a scientific journal, in 2010. Activity 2003 2004 2005 2006 2007 2008 2009 2010 1 X 2 X 3 X 4 X 5 X X X X X 6 X X X X X 7 X 8 X X X X 9 X

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Inputs: Activity 2005 2006 2007 2008 2009 2010 Research contracts1 80 000 80 000 80 000 80 000 80 000 Project Officer to attend 3rd WCCA

3 000

RCMs 30 000 33 000 33 000 30 000 Publications 5 000 TOTAL 113 000 113 000 80 000 113 000 110 000 5 000 1Includes cost of isotopes and minor items of equipment Assumptions: a) Adequate inter-disciplinary teams established and field and laboratory facilities available to conduct the programmed research.

b) Adequate training in nuclear techniques provided in conjunction with first RCM. c) Research not interrupted by catastrophic climatic or other events. d) Research contract obligations fulfilled. e) Agreement holders will provide strategic support to implement the main elements of the project. f) Continuity of CRP management and funding provided by IAEA.

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Logical Framework: Narrative Summary Verifiable Indicators Means of Verification Important

Assumptions A.1. Overall objective To enhance the productivity and sustainability of farming systems through a better understanding of the principles and practice of CA

N/A N/A N/A

A.2. Specific objective To quantify the individual and interactive effects of conservation tillage practices, residue management, crop rotations, nutrient and water inputs to increase soil organic matter, resource use efficiency, agricultural productivity and environmental quality

Individual and interactive effects of key components of CA on soil organic matter stocks, resource use efficiency, agricultural productivity and environmental quality investigated

Crop yield data; data on resource use efficiency; data on soil organic matter; data on environmental quality

Support from NARS; close co-ordination provided between contract and agreement holders and the Agency; appropriate technical and managerial support provided by the Project Officer; adequate funding available; experimental protocols agreed at first RCM

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Narrative Summary Verifiable Indicators Means of Verification Important

Assumptions A.3. Outputs 1. Data on carbon, water and nutrient dynamics under CA in diverse agroecosystems

Comprehensive and verifiable data sets from a range of agroecosystems.

Annual reports Appropriate experimental design and sampling strategies. Effective research teams. Sufficient human, institutional and financial resources. Favourable climatic conditions.

2. Means to extrapolate experimental findings across and between regions.

Modelled outputs. Decision support tools.

Models used to extend results beyond the experimental areas

Modelling expertise available in participating countries and at IAEA

3. Enhanced capacity of NARS to conduct integrated soil, water and nutrient management studies with the aid of nuclear and related techniques.

Contract holders are trained and use nuclear and related techniques in their research.

Successful completion of training workshop at first RCM. Annual progress reports. Publications. New project initiatives formulated.

Contract holders receive sufficient training. Equipment and analytical facilities available in institution. Scientists in CRP remain active in research and obtain competitive research grants.

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4 Research findings communicated to the wider community

Research results disseminated through publication of TECDOC, and/or special issue of Scientific Journal guidelines, scientific papers, conferences and workshop presentations.

Citations in abstracting journals. Demand for publications. Website visits.

Contract holders write manuscripts; project officer co-ordinates publications.

Narrative Summary Verifiable Indicators Means of Verification Important

Assumptions A.4. Activities 1. Consultants’ Meeting (CM) formulates CRP

Consultants’ Meeting held and project document prepared by September 2003

Report of Consultants’ Meeting. Project document completed.

Consultants available and actively participate in CM; PCC approves CRP

2. Project Officer and Consultants identify key institutions and personnel to participate in CRP

Project Officer gathers information and contacts prospective clients

Research contract proposals and agreements submitted

Appropriate institutions and scientists notified of CRP

3. Research network formed through research contracts and agreements

Research proposals and agreements received by July 2004 and evaluated by September 2004.

Contracts and agreements awarded; CRP commences Jan.- Feb. 2005

PCC approves contracts; Scientists and funding available

4.1st research co-ordination meeting to finalize work plan and experimental protocols

By June 2005 RCM and workshop held. Work plans and experimental protocols developed and agreed.

Report of RCM Scientists and funding available

5. Research specified in work plan conducted according to timeframe

Progress reports submitted on time

Individual annual reports

Scientists and funding adequate to conduct research

6. 2nd research co-ordination meeting reviews progress and plans research

RCM held in Morocco by Sept 2006. Annual progress reports submitted on time

Report of RCM Scientists submit reports and participate in RCM

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7. Mid-term review of CRP conducted

By Dec. 2006, review document submitted to PCC

Review document in prescribed format

Project officer prepares document in timely manner

8. 3rd research co-ordination meeting reviews progress and plans research

By April 2008 RCM held. Annual progress reports submitted on time

Report of RCM Scientists submit reports and participate in RCM

9. 4th research co-ordination meeting reviews CRP activities and formulates conclusions and recommendations

By Oct 2009 final RCM held. Final reports and manuscripts submitted on time

Final reports and manuscripts submitted. Report of final RCM

Scientists submit reports and participate in RCM

10. Publications By Oct 2010 all manuscripts received, edited and peer-reviewed where necessary

TECDOC or special journal issue published.

Manuscripts of sufficient quality received. Funds available for editing and publication.

Brief Summary for the Agency’s Bulletin: Conservation agriculture (CA) is a management system that maintains a continuous soil cover through surface retention of all crop residues, reduced or zero tillage, and the use of cover or green manure crops in rotations. CA is practiced on a total of 72 Mha of cropland worldwide, with the proportions of total croplands under CA being 47.5 % in Latin America, 36.7 % in North America, 12.5 % in Australia and 3.3 % in the rest of the world. CA has potential application in all agroecological zones, and is expected to expand rapidly in Asia and more gradually into Africa and Europe as socio-economic conditions permit. Many positive benefits are claimed for CA including inter alia reduced soil erosion, improved soil fertility, better water relations, soil organic matter accumulation, reduced soil compaction, increased soil biodiversity, soil resilience to climate change and greenhouse gas mitigation, all of which interact in a complex way to increase agricultural productivity and system sustainability. However, there is a paucity of experimental data to support many of these claims. The overall objective of the CRP is to enhance the productivity and sustainability of farming systems through a better understanding of the principles and practice of CA. More specifically, the individual and interactive effects of conservation tillage practices, residue management, crop rotations, nutrient and water inputs on nutrient (N and P) dynamics and use efficiency by crops, biological fixation of nitrogen, carbon dynamics, greenhouse gas emissions, water use efficiency, below-ground biodiversity are investigated using 15N, 13C and 32P isotopes as well as neutron probes. The project was implemented in 2005, with its first RCM held on 13-17 June 2005 in Vienna. Eleven participants (8 research contracts, 2 technical contracts and one research agreement) from Argentina, Brazil, Chile, Kenya, Morocco, Uganda, Turkey, Uzbekistan, India, Pakistan and Australia attended the meeting. The second RCM will be held in Rabat, Morocco, on 11-15 September 2006.