Realizing sustainable agricultural mechanisation
Soil Health for Soil and Water Management in Conservation Agriculture
Amir KassamACT, University of Reading (UK) and FAO
Training Manuals Pretesting Workshop, Comprehensive Conservation Agriculture Programme,
Ministry of Agriculture, Water & Forestry, Rundu, Namibia, 23-27 October 2017
Realizing sustainable agricultural mechanisation
1.Historical perspectives
2.What is Conservation Agriculture (CA)?
3.Terminologies related to CA
4.Application of the CA principles
5.Opportunities for CA systems
6.World adoption trends of CA
7.CA for challenging situations
8.Overall challenges
Contents
Realizing sustainable agricultural mechanisation
Food Security more urgent in Africa in coming years
1.Global pop. to increase by 33% to 9 billion by 2050
2.Africa’s to increase by 115%; by 21% in Asia
3.60% more food worldwide; 100% in Africa
4.Worldwide hunger decreased by 132 million in last 20 years; it
increased by 64 million in Africa.
5.Threatening climate change challenges
6.Farming related land resource degradation
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Soil degradation world map – GLASOD (FAO 2000)
Millennium Ecosystem Assessment 2005 – 89% our ecosystems degraded or severely degraded, only 11% in reasonable shape.
“soil degradation can get us before climate change does”
All agricultural soils show signs of degradation
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“Dirt – the erosion of civilizations” by David R. Montgomery (Prof. of Earth and Space Sciences at the University of Washington in Seattle, leads the Geomorphological Research Group, member of the Quaternary Research Centre):
• Soil is a thin skin of earth • Soil formation is very slow• In human history entire empires have
disappeared due to soil degradation (Greeks, Romans, Maya etc.)
• Soil tillage was the first agricultural operation performed.
• Any level of continuous mechanical soil tillage results in degradation processes exceeding by far the natural soil formation processes= Not sustainable
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BUT Conventional land preparation
regular tillage, clean seedbed, exposed
Effects:• Loss of organic matter• Loss of pores, structure soil compaction• Destruction of biological life & processes
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Rothamsted Research
LEAF’s Simply Sustainable
Soils Solution for improving
sustainability of land.
It’s not the terrorists on both sides who
are destroying civilizations, it’s the
plough!
Six simple steps for your soil to help
improve the performance, health and
long-term sustainability of your land.
Root cause of degradation
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25cm
30cm
10cm
But underneath?
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Tillage-induced Carbon Dioxide Loss
and wind erosion
CO2CO2
Reicosky
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Dust storms& sand dunes in GBAO, Tajikistan (April 2015)
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Residue retention distinguishes CA from conventional farming systems
soil crusts – no mulch low SOM
CLODS OF TOPSOIL FROM ADJACENT PLOTS
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Tajikistan – April 2015
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With rice ……
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Rain
Run-off
(erosion)
leachingSoil Structure
Organic Matter
Soil Biota
Soluble elements
of organic or synthetic origin
Tilled soil Not-disturbed soil
Destination of Rainwater
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TILLAGE AGRICULTURE -- Erosion
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Google image, 16 February 2014Sediment Plumes – The Guardian
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(Brisson et al. 2010)
Stagnating Yields (yield gap)
Rising-plateau regression analysis of wheat yields throughout various European countries
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But inputs and input costs going up, diminishing returns setting in,
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Runoff and soil erosion – Andalusia, Spain
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FOR AGRICULTURE (AND SOCIETY)• Higher production costs, lower farm productivity
and profit, sub-optimal yield ceilings, poor efficiency and resilience
FOR THE LANDSCAPE (AND SOCIETY)• Dysfunctional ecosystems, loss of biodiversity,
degraded ecosystem services -- water, carbon, nutrient cycles, suboptimal water provisioning & regulatory water services etc.
19
Consequences of tillage-based agriculture
at any level of development
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What happens in a tilled soil?
• it loses cover and protection
• reduced biodiversity: more bacteria, less major species
• oxygen is added, accelerating decomposition of organic matter; water soluble nutrients are released
• connected macro pores are destroyed; water infiltration rates reduced;
• aggregate stability destroyed, water & nutrient retention capacity destroyed
• contaminated waters leave as surface runoff with soil, organisms, nutrients (mineral or organic origin), pesticides, and as groundwater with leached minerals
The root problem:
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Instead: What happens in an undisturbed soil?
• Soil formation, minimal erosion, reversed degradation (1 mm soil/year)
• Increase of SOM 0.1-0.2% per year
• Soil structure is formedby action of soil biota(roots, fungi, fauna)
• Better adaptation to extreme rainfall events through betterinfiltration (less flooding even without terraces and reservoirs)
• Better adaptation to drought: more SOM = more water, deeper rooting, less water evaporation losses
• Better soil-mediated ecosystem services
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A healthy soil is a living biological system
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Soil health -- Definition
Soil health is the capacity of soil to function as a vital living system, within ecosystem and land use boundaries, to sustain plants and animal productivity, maintain or enhance water and air quality, promote plant and animal health …… Management of soil health thus becomes synonymous with ‘management of the living portion of the soil to maintain the essential functions of the soil to sustain plant and animal productivity, maintain or enhance water and air quality, and promote plants and animal health’ (Trutmann, 2000, Cornell)
Soil quality ~ soil health
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Soil health -- Definition
Soil health refers to the integration of biological with chemical and physical approaches to soil management for long-term sustainability of crop productivity with minimum negative impact on the environment. Healthy soils maintain a diverse community of soil organisms that help to control pests, form beneficial symbiotic associations with plant roots, recycle essential plant nutrients, improve soil structure…… (Wolf, 2000)
Soil quality ~ soil health
soil health
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A healthy soil is a living biological system
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Soil food webs…..
Plus food webs above ground
Pest-predator dynamics
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Soil productive capacity (vs. fertility) is derived from several components which interact dynamically in space and time:
• Physical: architecture - pore structure, space & aeration• Hydrological: moisture storage -
infiltration• Chemical: nutrients,
CEC, dynamics• Biological: soil life and
non living fractions• Thermal: rates of biochemical
processes• Cropping system: rotation/association/sequence
A productive soil is a living system and its health & productivity depends on managing it as a ‘complex’ biological system, not as a geological entity.
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Water and healthy soil
In CA soils
• Soil surface open
• 50-60% air space
• 50% of this air space can hold moisture
In tilled soil
• Soil surface closed
• 10-30% air space
• <30% of air sapce can hold water
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Soil formation
• The rock and subsoil upon which the multilayered soil horizons sit weathers from the bottom but the soil itself as a living system forms from the top through biological processes involving soil fauna and vegetation as permitted by the prevailing moisture and temperature conditions.
• The biological processes of soil formation are influenced by the parent material, climate, and vegetation, and in agricultural soils, by how the producer manages the soil under the altered conditions.
background
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Major soils
37% Arenesols
27% Leptosols
6% Cambisols
8% Regosols
82 M ha
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Arenosols are sandy-textured soils that lack any significant soil profile development. They exhibit only a
partially formed surface horizon (uppermost layer) that is low in humus, and they lack subsurfaceclay
accumulation. Given their excessive permeability and low nutrient content, agricultural use of these soils
require careful management. They are found in arid regions of the earth.
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Leptosols
A Leptosol is a very shallow soil over hard rock or highly calcareous material or a deeper soil that is extremely gravelly and/or stony.
Leptosols are unattractive soils for rainfed agriculture because of their inability to hold water,[1] but may sometimes have potential for tree crops or extensive grazing. Leptosols are best kept under forest.
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Cambisols are characterized by the absence of a layer of accumulated clay, humus, soluble salts, or
iron and aluminum oxides. They differ from unweathered parent material in their aggregate
structure, colour, clay content, carbonate content, or other properties that give some evidence of
soil-forming processes. Because of their favourable aggregate structure and high content of
weatherable minerals, they usually can be exploited for agriculture subject to the limitations of
terrain and climate.
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A Regosol is very weakly developed mineral soil in unconsolidated materials.
Regosols are extensive in eroding lands, in particular in arid and semi-arid
areas
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her
● Fotos grandes. Solo arrastra una nueva imagen y pásala para átras
Path to waterfall on private property brings income to locals in the form of ecotourismMonteverde Cloudforest Reserve
provides important source of water in landscape and downstream
Windbreaks provide habitat and corridors for wildlife, control erosion and protect livestock from wind
Shaded coffee extends wildlife habitat from reserve and reduces erosion
All fences are live rows of trees
Coffee, corn, sugar cane and other products are sold at a local cooperative
Ecoagriculture landscapes: harmonizing multiple objectives at farm, community, landscape scales
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Ecosystem services
Water cycling Carbon cycling Atmospheric circulation
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Source: The Millennium Ecosystem Assessment (2005)
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Length of rainfed growing period zones
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FOR AGRICULTURE (AND SOCIETY)• Higher production costs, lower farm productivity
and profit, sub-optimal yield ceilings, poor efficiency and resilience
FOR THE LANDSCAPE (AND SOCIETY)• Dysfunctional ecosystems, loss of biodiversity,
degraded ecosystem services -- water, carbon, nutrient cycles, suboptimal water provisioning & regulatory water services etc.
40
Consequences of tillage-based agriculture
at any level of development
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The New Paradigm of Sustainable Intensification
Technical objectives of SI
• Agricultural land productivity (output)
• Natural capital and flow of ecosystems services
Simultaneously
• Enhanced input-use efficiency
• Use of biodiversity – natural and managed
(and carbon) to build farming system resilience (biotic and abiotic)
• Contribute to multiple outcome objectives at farm, community & landscape scales
And
• Capable of rehabilitating land productivity and ecosystem services in degraded and abandoned lands
But how to achieve such multiple objectives?
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CA totally compatible with
the objectives of SI
What does CA offer: Mobilizing greater crop and land potentials
sustainably?42
Switching to sustainable solutions
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Concept:CA is a no-till production system. It is defined by three interlinkedprinciples (to correct what is missing):
1. No or minimum soil disturbance (permanent no-till seeding & weeding).
2. Permanent organic soil cover. 3. Diversification of species in rotations, sequences or associations.
Along with other GAPs SPI
Conservation Agriculture
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Ecological foundation for sustainable agriculture production is provided by application of Conservation
Agriculture principles
No/Minimum soil disturbance
Soil Cover Crop Diversity
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Conservation Agriculture – Ecological foundation
…alone do not respond to all the challenges of achieving a Sustainable Intensification.They needs to be complemented by allgood practices known.But CA practices provide an ecological base or foundation for Sustainable Intensification as a necessaryset of conditions.
No/minimum soil disturbance
Soil Cover Crop Diversity
IntegratedPest
Management
IntegratedPlantNutrientManagement
IntegratedWeed
Management
IntegratedWater management
Sustainablemechanization
Compaction management,CTF
Permanent Bed and
FurrowSystems
Systemof RiceIntensification
Good seedGenetic potentialGenetic resources mgmt.
Pollinator/Biodiversity
management
Sustainableland management
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What does CA do
Crop
Diversity
No-Till
plus OM
Management
Soil
structure &
biota
Nutrient &
water
cycling
Plant
Insect pests
& diseases
Weed
management
EcologicalProcesses
Spiral of Regeneration &Intensification
Integrated
CA systems
Anderson, R.L. 2005
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Table 1 Effects of CA components fully applied together
(Friedrich et al., 2009)
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Conservation Agriculture
CROP
• Increased & stable yields, productivity,
profit (depending on level and degradation)
• Less fertilizer use (-50%), also no fertilizer
less pesticides (-20->50%), also no pesticides
• Less machinery, energy &
labour cost (50-70%)
• Less water needs (-30-40%)
LAND
• Greater livestock and human carrying capacity
• Lower impact of climate (drought, floods, heat, cold) &
climate change adaptation & mitigation
• Lower environmental cost (water, infrastructure)
• Rehabilitation of degraded lands & ecosystem services
Wheat yield and nitrogen amount for different
duration of no-tillage in Canada 2002 (Lafond
2003)
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0 30 60 90 120
nitrogen (kg/ha
Gra
in y
ield
(t
/ha)
20-year no-tillage
2-year no-tillage
Patterns of benefits with CA – small or big farms
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COMPARISON
A FARMER’S TRIAL – CLODS OF TOPSOIL FROM ADJACENT PLOTS, PARANÁ, BRAZIL (Shaxson 2007)
PRO-BIOTIC ▲ ANTI-BIOTIC ▲
Topsoil after 5 years with retention Topsoil after regularly-repeated diskof crop residues and no-till seeding. tillage, without retention of residues
Soil health and adverse effect of tillage agriculture
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WHAT DOES IT LOOK LIKE CLOSE-UP?
SAME SOLIDS - DIFFERENT SPACES
IMPLICATIONS FOR ROOTS AND RIVERS
Shaxson (2007)
Soil health & adverse effect of tillage agriculture
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SOIL CARBON – Mr. Reynolds’ farm in Lincolnshire
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Residue retention distinguishes Conservation Agriculture from
conventional farming systems, which are characterized by leaving the
soil bare and unprotected, exposed to climatic agents.
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Water infiltration, just after a thunderstorm
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Situation in Malawi – Tilled & CA
Tilled CA
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Gains in Rainfall Infiltration Rate with CALess flooding – improved water cycle
Landers 2007
tillage + cover, measured
no-till + cover, measured
tillage, no cover, measured
tillage + cover, calculated
no-till + cover, calculated
tillage, no cover, calculated
Time (min.)
Ac
cu
mu
late
d I
nfi
ltra
tio
n r
ate
[m
m. h
-1]
Benefits of CA
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Plough No-tillage
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Longer term maize grain yields on farmers fields in Malawi – Lemu -- CSA
Harvest year
2007 2008 2009 2010 2011 2012
Maiz
e b
iom
ass y
ield
(kg
ha
-1)
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
Conventional control, maize (CPM)
CA, maize (CAM)
CA, maize/legume intercropping (CAML)
aa
a a
b
b
aa
bb
a
a
b
aa
b
a a
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Regional perspective – Southern Africa
Conventional tillage yield (kg ha-1
)
0 2000 4000 6000 8000
Conse
rvat
ion a
gri
cult
ure
tre
atm
ent
yie
ld (
kg h
a-1)
0
2000
4000
6000
8000
Planting basins, Mozambique
Jab planter, Mozambique
Direct seeding, Zimbabwe
Ripper, Zimbabwe
Direct seeding, Zambia
Ripper, Zambia
Direct seeding, Malawi
Intercropping, Malawi
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Longer term maize grain yields on farmers fields in Malawi - Zidyana
Zidyana
Year
2005 2006 2007 2008 2009 2010 2011 2012
Yie
ld d
iffe
rence
bet
wee
n C
A a
nd C
P (
kg h
a-1
)
-4000
-2000
0
2000
4000
6000
CAML
CAM
C
CIMMYT– Thierfelder et al.
Recall what happens when someone falls ill or becomes a drug addict? It takes time to bring the person back to health, and similarly it takes time to bring the soil back health
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Earthworm population
0
50
100
150
200
250
300
plough no-tillage natural
meadow
bio
mass g
/m2
other species
Lumbricus
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Biodiversity
Soil food webs…..
Above groundfood webs &habitates for natural enemies of pests
Ground-nestingbirds, animals and insects
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Source: Dijkstra, 1998
Empirical evidence: The Frank Dijkstra farm in Ponta Grossa, Brazil – Sub-humid tropics
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Wheat yield response to nitrogen fertilization (according the model)
Carvalho et al., 2012
International Scientific Conference: The role of agriculture in providing ecosystem and societal services
Balti Alecu Russo State University, Moldova, 25, Nov. 2014
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Economic viability-Malawi
Lemu Zidyana
CP CA CAL CP CA CAL
Gross Receipts 528.6 881.5 979.7 1047.2 1309.5 1293.7
Variable costs
Inputs 238.5 341.0 353.6 221.7 323.7 346.1
Labour days (6 hr days) 61.7 39.9 49.4 61.7 39.9 49.4
Labour costs 159.5 103.2 127.9 155.6 100.7 124.7
Sprayer costs 1.7 1.2 1.7 1.2
Total variable costs 398.1 445.9 482.8 377.3 426.1 472.1
Net returns (US$/ha) 130.5 435.5 497.1 669.9 883.3 821.9
Returns to labour (US$/day) 1.8 5.2 4.9 5.4 9.8 7.6
Source: Ngwira et al., 2012
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SUMMARY OF ANNUAL EXPENSES
70
40
60
77,5
85
REDUC-TION
(%)
15 000 €25 000 €Labour
18 347,55 €61 068,88 €TOTAL ANUAL
7 110 €17 460 €Fuel
1 840,40 €8 158,41 €
Maintenance andrepair of tillage/drilling implements
1 507,15 €10 450,47 €Maintenance andrepair of tractors
DIRECT DRILLING(Year 2003)
CONVENTIONAL TILLAGE
(Year 2000)
70
40
60
77,5
85
REDUC-TION
(%)
15 000 €25 000 €Labour
18 347,55 €61 068,88 €TOTAL ANUAL
7 110 €17 460 €Fuel
1 840,40 €8 158,41 €
Maintenance andrepair of tillage/drilling implements
1 507,15 €10 450,47 €Maintenance andrepair of tractors
DIRECT DRILLING(Year 2003)
CONVENTIONAL TILLAGE
(Year 2000)
Instituto de Agricultura Sostenible CSIC , Cordoba, Setiembre 2005
Farm power – 4 tractors with 384 HP under tillage & 2 tractors with 143 HP under no-till Farm near Evora, South Portugal
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Realizing sustainable agricultural mechanisation
Two QuestionsGroups 1-3
Given the wide range of benefits arising from a healthy agricultural soil, identify and explain its key productivity enhancing properties or indicators.
Groups 4-6
Given the built-in integrated soil and water management practices in CA systems, how can CA systems benefits from traditional soil and water conservation methods?
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Management of soil mulch cover in CA systems
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Soil mulch cover• Comprises stubble, any plant biomass on the soil surface
• 30% soil cover reduces runoff and erosion by 80% -- minimum desirable cover
• Crop residue cover required continuously to enhance soil health/life and productivity, and build and protect the soil.
• Residue cover plus cover crops in CA systems contribute to integrated weed control and insect pest control, and to crop health.
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Soil mulch management
• Soil mulch cover contributes to water, nutrient and carbon cycles.
• Cover crops can provide biomass for soil mulch development while enhancing soil health and productivity
• In dry areas in Nambia, tine seeders would be able to cope with low levels of crop residues but some tine seeders can cause medium to high soil disturbance
• Disk seeders would better manage higher levels of mulch cover and cause low soil disturbance.
• Cover crops can be single or mixtures, planted sole or in mixed cropping.
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CA is applicable to all crops & cropping systems:
Cropping systems:
soya
wheat
cornvegetable
rice
potato
perennialsagroforestry
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72Two-wheel no-till seeder – small farmers, Bangladesh
No-till rice
In North Korea
Multi-row tine ‘Happy Seeder’ –medium farmers, India
No-till riceIn Bihar India
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CHINA: innovation with raised-bed, zero-till SRI field;measured yield 13.4 t/ha; Liu’s 2001 yield (16 t/ha) set provincial yield record and persuaded Prof.Yuan Longping
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CA-SRT rice-based system, Saguna Baug, Maharastra, India – Mr. Chandrashekhar
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All crops can be seeded in no-till systems Potatoes
under no-till after rice in North Korea
(Friedrich, 2006)
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Mechanized or manual
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Rehabilitation of degraded rangelands
Opportunities – Gissar, Tajikistan
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• Erosion: North America, Brazil, China
• Drought: China, Australia, Kazakhstan, Zambia
• Cost of production: global
• Soil degradation: global
• Ecosystem services: global
• Climate change A&M: global
• Sustainable intensification: global
Spread is farmer-led but needspolicy & institutional support
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Drivers for adoption of CA
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Group questions
Given your understanding of Conservation Agriculture (CA), formulate up to three CA cropping systems that would be: market responsive, socially desirable and be capable of producing enough biomass to develop soil mulch and meet livestock feed requirements.
Realizing sustainable agricultural mechanisation
CA-agriculture of the future – the future of agriculture
More [email protected]://www.fao.org/ag/ca http://www.fao.org/ag/save-and-grow
Join the CA-CoP!
Thank You!
June 2011
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