Environmental Variables Affecting the Success of Conservation Farming in Zambia Lydiah Gatere 1, Rob

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Environmental Variables Affecting the Success of
Conservation Farming in ZambiaLydiah Gatere
(1), Robert Delve (2), Peter Hobbs (1), Steve
DeGloria (1), Johannes Lehmann (1) (1) Department
of Crop and Soil Sciences, Cornell University,
Ithaca, USA (2) TSBF-CIAT, Uganda
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Five principles Involved in Conservation Farming
Practices in Zambia

• No burning but crop residue retention from prior
  harvest
• Crop rotation with minimum 30 legume
• Dry season land preparation using restricted
  minimum tillage methods (hand-hoe) laid out in
  precise grid of 15,850 basins per hectare
• Input application and planting in fixed planting
  stations

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Conservation Farming (CF) Influence on Yields

• Average maize yield 1.2 ton ha-1 after collapse
  of subsidies and rural credit facilities
• Farmers lose 1 to 2 grain yield per day delayed
  in planting after onset of rains but increase
  with 400kg ha-1
• Potential of CF hand-hoe basins cultivation 6-8
  tons ha-1 grain yield
• CF basins increases yield 20-100 (NGO farmers
  have access to HYV seeds fertilizers)
• CF cultural practices 400kg ha-1
• Source IFPRI/FSRP Survey, (Haggblade et al 2003)

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Transect of the Three Agroecological Zones
Transect COMACO and ASP region.

• Agroecological Zones
• I lt700mm rainfall p.a.
• Rift Troughs
• Loamy and clayey soils with coarse to fine loam
  top soils
• II 700- 1000mm rainfall p.a.
• Degraded plateau
• Moderately leached clayey to loamy soils
• III gt1000mm rainfall p.a.
• Degraded plateau
• Highly weathered and leached clayey to loamy
  soils

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Research Questions 1) How well does
conservation farming improve crop yields under a
wide gradient of environmental condition?

• Objective 1
• Establish the effects of (a) mean annual
  precipitation (MAP), (b) soil properties
• ( clay) and, (c) landscape position increases
  on crop yields through conservation farming.
• 2) Why does conservation farming improve crop
  yields? What are the reasons and how do these
  reasons depend on location?

Objective 2. Determine the factors influencing
yield improvement through conservation farming
under varying environmental conditions.
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Approach, design, matrix
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Field Plot Layout
TT2 Conservation Farming (CF) Farmer
Managed Practiced (control)
TT1 Traditional / Conventional Plot (control)

• Nitrogen 200kg ha-1
• Potassium Phosphorus 100 kg ha-1 and
  micronutrients
• Organic matter 6 ton of C ha-1 (dry
  matter)
• Plot dimension 3.5 by 4.5m (5 x 5 basins per
  treatment).

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Analysis

• 1) Site Characterization
• Soil properties pH, Cation Exchange Capacity,
  Extractable metals, Total Carbon Nitrogen,
  Exchangeable bases Na, Mg, Na, K (June
  2008)
• 2) Plant nutrient uptake
• Plant analysis Apparent nutrient use efficiency
  and (maybe water stress)
• Total Carbon and Nitrogen
• (use 2nd year season above ground plant biomass
  and grain yield December 2008)
• 3) Estimation of Soil Water Balance
• NewHall Simulation Model
• Simulating soil moisture and temperature regimes
• Using long term monthly Temperature from CRU
  (Climatic Research Unit) data and real time
• Mean Annual Precipitation (CRU) and real time

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• Increasing nutrient availability is more
  important than increasing water availability

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• Farmer managed has various quality of compost
• Cow manure- mobilization of nutrients
• Biochar- improves CEC

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• Wide range of yield values on moderate to higher
  slopes during the moderate weather conditions

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Conclusion

• The second season will determine a third season
  to establish the effect of residual organic
  matter
• Investigate the potential to improve nutrient
  availability by organic matter additions of
  contrasting quality in conservation farming along
  environmental gradients.
• Soil analysis of adoption of conservation farming
  through a chronosequence study

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• Thanks

• Zambia
• -Agriculture Support Program SIDA
• Conservation Farming Unit
• World Agro-forestry (ICRAF)
• University of Zambia