conservation agriculture: fundamentals
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Conservation Agriculture
Pictures and text (in part) by Dr Des McGarryContributions from Dr Jack Desbiolles (Ashworth et al., 2010) and Baker et al., (2007)
Jack McHugh
from Local to Global level
via
Conservation Agriculture
Mitigating Land Degradation
&Improving Land and
Environment Condition
Farming in a natural way
Represents:
“a shift in our philosophy towards the land”
“do not beat the land into submission
- rather work in harmony with it”
Conservation Agriculture (CA)
To conserve, improve and make more efficient use of natural resources through integrated management of available soil, water and biological resources combined with external inputs.
What is the goal of CA?
CA is a resource-efficient and resource-effective form of agriculture.
What is Conservation Agriculture ?
The foundation underlying the three principles is their contribution and interaction with soil carbon, the primary determinant of long term sustainable soil quality and crop production
Baker et al., (2007)
Baker et al., (2007)
Agricultural policies: to encourage farmers – leads toincreased air & water quality and productivity, and mitigates GHGs
CA is about feeding and greening the world for global sustainability.
Conservation Agriculture- a question of how much soil disturbance
It is a question of soil disturbance – Reduced tillage = Intermediate in soil quality effects.
They define the tillage equipment & operation characteristics as they relate to the soil volume disturbed and the degree if residue mixing.
True Conservation = Carbon & soil moisture Management
Zero till
No till
Conservation tillage
Reduced tillage
Minimum till
Controlled traffic
farming
Ridge tillage
Organic farming
Direct drill
PRB
Direct Seeding
Precision Ag
Direct planting
CA CA
CAStrip
tillage
Mulch tillage
Baker et al., (2007)
There is nothing wrong with our soils except our interference. It can be said with considerable truth the use of tillage has actually destroyed the productivity of our soils. (Faulkner, 1942)
Philosophy of CA
‘Soil does not need tillage for effective crop production’ -This is the basis for the CA philosophy-
Tillage is not necessary for crop production.
Crop residues are a very valuable part of farming systems and must be retained in full and remain on the surface as a mulch.
Permanent all year round soil cover is essential.
Control and promotion of natural biological soil process through rotation.
Soil degradation and erosion is a symptom of an unsuitable farming system.
Vehicle traffic management is adopted within an integrated systems approach.Ashworth et al., (2010)
Important benefits of CA
Increased SOM Improved soil quality Increased available plant nutrients Less runoff and increased plant available water Reduced soil erosion Improved crop production economics Reduced labour requirements Reduced machinery costs Reduced fossil fuel inputs Improved global environment
Fredrick Movie+ & - impact of CA……..aware of issues – farmer support/networksNutrient Efficiency………Dynamics, VAM, Rhizobia, rooting environmentSustainability role……….Drought, erosion, WUECA in Canada…………….Lot to learn Rotations, residue, demands for crops – force farmers to monocultures
CROP ROTATIONS
in CA - are “critical”
- Disease control- Nitrogenous plants
- Biodiversity
ROTATE
ROTATE ROTATE
Jose Benites, FAO
on the Pampas of Argentina – 12 years zero till
Roberto Pieretti
3 years no-till on a Russian chernozem
Improved soil biodiversity…
Depth (cm)
C W&B
(%)
N C
0 - 10 1.54 0.89
10 - 20 1.45 0.81
20 - 30 1.34 0.71
Soil Carbon data for the 12 Years of No Till (N) and conventional (C) sites (Walkley and Black extracted OC)
Almost 50 % more OC in the no-till site – to 30 cm- 12 years of No-Till
Organic Carbon levels with No-till
Increases – reported globally
McGarry and Sharp, ISTRO, 2003
From - Emilio-Jesús GONZÁLEZ-SÁNCHEZ. AEAC.SV – ECAF – University of Córdoba
Weed Control with No-till
Simba (1999). ECO tillage reduces inputs and maximises crop yields. Simba International Ltd., Sleaford, Lincolnshire, England. pp. 26.
Proven reduced Glyphosate (Roundup) use with time under No - Till
Environmental concerns with continued usage of herbicides
Large fields – wheat, cotton, soybean, maize…
Most common perception of CA
Jose Benites, FAO
South S. Amer Video
LABRANZA PÓS COSECHA DE
Sweet pepper
Cassava
CA is applicable to virtually all crops OnionsCucumber
Tomato SquashJose Benites, FAO
Hoe-based farming, 0.5 ha farms; red sandy loam, Zambia
Video
Consequences:- vast labour & time needs- yield losses if it rains- total loss if drought- widespread erosion(see arrows)
Conservation Agriculture:- using “planting basins”- retain crop residues - + rotation crops- 80% time saving
(“drudgery”)- land ready before rains- yields up 65 to 75% (maize &
cotton)
- hunger alleviated- with less resources used
Peter Aagard and Dutch Gibson, CFU, Lusaka, Zambia
40,000ha of CA
FAO – Kazakhstan – CIMMYT project: “CA for Sustainable Crop Production in Northern Kazakhstan”
Prof. Murat Karabayev, CIMMYT
Now 1.3 Mha under CA. (2009)
And a State Policy, actively promoted by Ministry of Agriculture
Kazakhstan; <300mm rain / year
Traditional practice:- mechanical fallow
Picture © CherezdanovPicture © Cherezdanov
Traditional practice (fallow cultivation) - unsustainable- weed control was very poor- soil moisture losses were high- fuel and spares for tractors were scarce and
costly.
Since 2000 - introduce CA components on 4 Farms:- no-till- chemical fallow- green manure crops 1. Already demonstrate “great potential”
2. Wheat production UP by:: 20-200 kg per hectare) 3. Due to better soil moisture under no-till
Machinery based, 1850 ha ; Australia; wheat and sorghum; 500mm rain/yr
No-till (5 yrs), controlled traffic (2 m); 1 tractor (240hp), 1 disc planter, 1 spray-coupe, 1 operator
- extended farm to unproductive clay loams; soil greatly improved- land doubled in value; crops every year; 0.5 t/ha wheat in drought year
“I farm for my soil moisture”
Excellent soil structure
12Mha of CA
Machinery based, ChinaACIAR project: 96/143: “Sustainable Mechanised Dryland Grain Production”
China Agricultural University - University of Queensland, Shanxi Agricultural Machinery Bureau
J.N.Tullberg, D. Freebairn, Prof. Gao Huanwen, Dr Zhai Tongyi
Zero till
Conventional
This project has demonstrated - No-Till with controlled traffic:1. reduces power requirements2. enhances the productivity and sustainability of cropping3. by avoiding the damaging soil energy inputs4. alternate, cheaper and more sustainable methods to conventional farming in these areas…
Experimental sites:- Linfen and Shouyang (Shanxi province) – start: 1997- Zhangbei and Western Shanxi (northern Hebei) -
1999
RESULTS: Water erosion increased by:• tillage (by 30%)• random traffic, tillage and residue burial (by 70%)• residue removal from tilled soil by (~105%)• wheel compaction, residue removal in no-till (by >200%)
1.3Mha of CA (2009)
No-till
Conventional till
Strong visible evidence of improved utilisation of rainfall..
2.65 t/haProtein: 15.5%
2.11 t/haProtein: 11.4%
Same Result – Foggia, eastern Italy
80,000 ha of CA (2009)
No-till “best” in driest years (1997 and 2001)
0
1
2
3
4
5
1995 1996 1997 1998 1999 2000 2001 Average
Gra
in y
ield
(t/
ha)
Conventional tillage
Sod seeding
324
393
226
412
288310
280
319
Data and graph from Professor Michele Pisante
Foggia trial results:: grain yield of durum wheat
From - Emilio-Jesús GONZÁLEZ-SÁNCHEZ AEAC.SV – ECAF – University of Córdoba
0.65 Mha of CA (2009)
Brazil, 600 ha ; Brazil – Herbert Bartz; maize and wheat; 800mm rain/yr
No till for 45 years !!!
Excellent soil structure- without cultivation
25.5 Mha of CA (2009)
Traditional farming
New beds each year (FRB)
ZT CTF
PRB
Darker colour, earthy, rough, soft, SOM
Grey colour, blocky, hard,
smooth
China, 0.5ha; Hexi Corridor; maize and wheat; 150mm rain/yr
No till for 4 years
Evolutionary phases of no-till farming (Sá, 2004)
Rolf Derpsch identified that
growers practicing a no till
system without full stubble
retention will probably never
leave the initial phase.
Converting to CA needs higher management skills
The first years might be very difficult for the farmers, therefore they might need support – from other farmers or from extension services – and perhaps even financial support to invest in new machinery such as zero-till planters
Necessary technologies are often unavailable
Few farmers take the risk of buying new machinery
Machinery dealers might not wish to promote CA
What are the issues?
Training, Educational, Empowering
Participatory activities
for farmers, agronomists & technologists
courses, seminars, forums, workshops, field days, farm trial sites, farmer field schools
Extension of CA?
CA field training in Embu/Kenya CA and Gender training – Machakos/Kenya
Women with beans under CA, Karatu/Tanzania Field day in Karatu/Tanzania with jab planter demonstrations
FAO
FAOFAO
FAO
Australia: “harness the power of local farmers”
Soil pit day - Swaziland
Farmer & technologist empowering days..
Uzbekistan: with tractor sales personnel
FFS- Zhangye, Gansu
* http://www.fao.org/ag/ags/AGSE/agse_e/general/OBJECT.htmand John Landers (2000) – World Bank Report
The many attractions and
multiple ecosystem level benefits of Conservation Agriculture *
FarmCommunitiesEnvironmentWatershedGlobal
Reduction in labour, time (less drudgery), fuel and costs
On mechanised farms:
smaller tractors possible (up to 40% smaller)
longer lifetime and less maintenance of tractors (life x2 or x3)
less power and fewer passes
hence reduced fuel consumption (up to 50%)
Better trafficability in the field – from controlled traffic
Earlier sowing (soil preparation eliminated)
Increased yields with decreased inputs
More stable yields, particularly in dry years
Improved infiltration and crop water use efficiencies
From: better soil structure, biodiversity & OM levels
Increased profit, at times from the beginning, after a few years.
Multiple ecosystem level benefits of CAFarm – level:
From - Emilio-Jesús GONZÁLEZ-SÁNCHEZ AEAC.SV – ECAF – University of Córdoba
More constant water flows in the rivers, re-activation of wells
Cleaner water due to less erosion
Less flooding
Less impact of extreme climatic situations
Less costs for road and waterway maintenance
Better food security
Increased wildlife (species and populations) in fields (protected
by retained residues; fed by increased biodiversity)
Multiple ecosystem level benefits of CA
Communities/Environment/Watershed:
Carbon sequestration (reduction of greenhouse effect):
CA farmers could receive carbon-grant payments;
Carbon sequestration and reduced energy (fuel) use
could = the human-induced increase in CO2.
Less fuel use in agriculture
Reduced CO2e emissions, and heat (fossil fuel burning)
Less leaching of nutrients and chemicals into
groundwater.
Less pollution of waters (river, lake, reservoir, ocean)
Greatly reduced erosion (wind and water)
Recharge of aquifers through better infiltration
At global level: Multiple ecosystem level benefits of CA
Multiple ecosystem level benefits
with…
Conservation Agriculture
It is strongly possible
&
very practical…to achieve
Finally…
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