Conservation agriculture (CA) is being promoted in Southern Africa partly for its benefits of reducing water and soil loss. This study examined whether CA is a promising option for smallholder farmers in Zambia to respond to increased rainfall variability and droughts or floods. The study found that as the percentage of cultivated area under CA increased over the study period, CA farmers adapted to flooding by back-filling flooded basins and continuing to adopt ripping. Farmers reported being able to harvest some crops from CA fields despite floods, whereas conventionally tilled fields failed. This suggests CA systems may be more robust during extreme weather and have potential for higher production during droughts and floods compared to conventional agriculture.

1. CONSERVATION AGRICULTURE AND RAINFALL
VARIABILITY IN ZAMBIA:
Is CA a promising option for responding to
droughts and floods?
Bridget Bwalya Umar and Progress. H.Nyanga

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Introduction
 Smallholder farmers in Southern Africa confronted by
risks related to climate, mostly rainfall
 Dependence on rain fed agriculture related to low
agricultural productivity and variability in production due
to water stress during critical crop development stages.
 Approaches for dealing with climatic risks include water
harvesting.
 Conservation Agriculture (CA) promoted partly for its
water soil and water loss reduction benefits (Mazvimavi &
Twomlow 2009)
 In-situ water harvesting effect is the main benefit of CA
basins (Enfor et al 2011).
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CA Basins
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CA Basins and Rainfall
 Improved water harvesting and water use efficiency in
low rainfall areas
 Problems of water logging in high rainfall areas.
 Basin variant of CA mostly promoted in low rainfall areas.
 However, with increasing rainfall variability, probability
for low rainfall areas receiving high amounts of rainfall in
a given season increasing.
 What happens then?
 We report on this
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Our study
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Our study
 Panel study from 2007 to 2010
 640-440 households
 interviews with farmers and key informants
 Field observations
 Focus group discussions, on experiences during drought
and flood periods.
 Yields from fields under CA and Conventional Agriculture
systems compared.
 Rainfall data for the study areas for the period.
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Results
Farming Season
2006/2007 2007/2008 2008/2009
Average area under CA (ha) 0.22 0.42 0.42
% of cultivated area under CA 11.5 16.5 24.9
Average are under CV (ha) 1.69 2.12 1.27
Total cultivated area (ha) 1.91 2.54 1.69
Average maize yield (tons/ha) 3.39 0.77 1.65
Average rainfall (mm) 1046.3a 1086.8a 858.6b
CV = Conventional agriculture. This includes the use of mould board plough and traditional hand hoe for tillage.
aMeans followed by the same letter in row are not statistically different at p≤ 0.05 probability level
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Results
 % of cultivated area under CA increased steadily over
the period.
 Flooding experienced during the 2006/2007 and
2007/2008 seasons in the low rainfall study areas.
 Large difference in the average maize yields between
2006/2007 and 2007/2008 seasons (importance of
rainfall distribution)
 Flooding during 2007/8 resulted in lower yields
(p=0.0003)
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Discussion
 Water logged basins were back-filled , raised to make
small ridges. (soil disturbance increased)
 FGD reported ability to harvest ”something” from CA
fields despite the floods compared to conventionally
tilled fields.
 Similar sentiments expressed for drought periods.
 Continued increase in area under ripping demonstrate
farmers’ confidence in the tillage system under flood
conditions.
 Benefits of early land preparation and early planting
associated with CA increases chances of survival of
maize, and other crops.
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Area under CA Tillage System
0.35
0.30
0.25
0.20
Area (ha)
Basins
0.15 Ripping
0.10
0.05
0.00
2006/2007 2007/2008 2008/2009
Farming season
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Conclusions
 CA farmers adapting to climatic variability
 Diversifying CA tillage systems to suit the climatic
variability.
 CA systems being perceived to be more robust in
instances of extreme climatic events
 Potential for higher production under CA during
incidences of both droughts and floods.
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Thank You!
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