This document summarizes a study on the adoption of Conservation Agriculture (CA) practices by smallholder farmers in Zimbabwe. CA involves minimum soil disturbance, permanent soil cover, and crop rotations. The study found that over three years, CA plots achieved higher maize yields than conventional plots. However, the contribution of CA to household food security was limited by small plot sizes. While the use of planting basins decreased from 100% to 89% from 2004-2009, adoption of other CA components like mulching and rotations was also limited by increased labor needs and lack of input and output markets. The study recommends improved extension support for CA and policies to enhance smallholder access to markets.

1. Conservation Agriculture Practices and
Adoption by Smallholder Farmers in Zimbabwe
Sep 2010
Introduction
Smallholder farming in Zimbabwe is constrained by poor soil
fertility,erratic rainfall and low yields (Donovan and Casey,1998).
The response to this crisis – the wide-scale distribution of food
aid and agricultural input assistance without an exit strategy
– is not a sustainable way of addressing the problem.Recently,
there has been a shift to relief assistance that improves soil
fertility,water conservation and environment protection such as
Conservation Agriculture (CA).
What is Conservation Agriculture?
CA is a way of farming based on enhancing natural
biological processes above and below the ground and is
characterized by three interlinked principles:
• Continuous minimum mechanical soil disturbance (planting basins)
• Permanent organic soil cover
• Diversification of crop species grown in sequence or associations (FAO,2010)
In Zimbabwe multiple donors are promoting CA as an efficient use of relief seed and fertilizer targeted at
resource-poor farmers.
Objectives
With an increasing up scaling of CA in Zimbabwe,this study reviews the relative success of the technology
adoption and practices over time.CA contribution to household food security is also assessed.
Methodology
The research is based on a panel study that started in 2006/07 and was repeated in 2007/08 and 2008/09 in 15
districts of Zimbabwe where various NGOs have been promoting CA for an extended period of time.
CA production impacts
Over the years CA plots consistently attained higher maize yields compared to conventionally plowed plots
(Figure 1).CA plots in lower rainfall areas of natural regions (NR) IV and V outyielded conventional plots in high
rainfall areas (NR II and III).
Although CA resulted in high yields the contribution of the technology to total household food security was limited
by small plot sizes.Plot sizes ranged from 1500 to 5000m2
.The proportional contribution of CA to total cereal grain
production was more than 50% in only 3 of the 15 surveyed districts (Bindura,Masvingo and Seke) (Figure 2).
CA adoption trends
The proportion of farmers who practiced the central component of CA,which is digging basins, decreased in
the 2008/09 cropping season from 100% in 2004/05 to 89% (Table 1).
Why some farmers are not practicing some components of CA
To address labor constraints associated with basin digging farmers are encouraged to stagger land preparation
activities – digging basins to start soon after harvest in July.Labor for winter weeding competes with other
off-season labor requirements and social obligations.It is recommended for farmers to use crop residues
for mulching,although this has a better demand in feeding livestock during the dry period.Also long term
mulching benefits are not apparent.Application of fertilizers is influenced by its availability through the
relief programs (Mazvimavi and Twomlow,2009).Rotation practices are on the increase,but hampered by
preferences of cereal staples and limited output market for legumes.
Conclusions and Recommendations
• CA contributes to higher yields than conventionally plowed plots and this is attributed to moisture
conservation and good management through timely implementation.
• Adoption of CA components has been limited by increased labor demand and unavailability of input-output
markets in the smallholder sector.
• The contribution of CA to food security is limited by small CA plot sizes.
• We recommend improved extension support in CA promotions and government policies that support
enhanced smallholder access to input and output markets.
References
Donovan G.and Casey F.,1998.Soil Fertility Management in Sub-Sahara Africa.World Bank Technical Paper No
408,Washington DC:World Bank,44pp.
FAO.2010.What is Conservation Agriculture? http://www.fao.org/ag/ca/1a.html accessed 14 May 2010.
Mazvimavi K and Twomlow S.2009.Socioeconomic and Institutional Factors Influencing Adoption of
Conservation Farming by Vulnerable Households in Zimbabwe.Agricultural Systems 101:20-29.
Table 1: Proportion of farmers practicing different CA
components (%).
CA components
Cropping season
2004/05 2005/06 2006/07 2007/08 2008/09
Digging of basins 100 99 99 97 89
Winter weeding 51 87 76 71 63
Application of
mulch
40 75 69 70 56
Application of
manure
89 88 89 87 80
Application of basal
fertilizer
71 75 74 66 38
Application of top
dressing
94 92 92 88 70
Post-planting timely
weeding
94 98 99 96 85
Crop rotation 8 13 13 18 19
Nyanga
Murehwa
Bindura
MtDarwin
GokweSouth
Chirumhanzu
Chivi
Hwange
Masvingo
Mangwe
Nkayi
Binga
Seke
Insiza
Chipinge
TotalCerealproduction(kg)
Minimal tillage by use of planting basins and
maintaining soil cover.
Diversification of crop species in CA.
Figure 1. Maize yields from CA plots and non-CA plots for
three cropping seasons.
Figure 2. The contribution of CA to total household food security
in 2008/09.
Kizito Mazvimavi,Putso Nyathi,Patrick V.Ndlovu and Isaac J.Minde
International Crops Research Institute for the Semi-Arid Tropics (ICRISAT),Matopos Research Station,P.O.Box 776,Bulawayo,Zimbabwe
NR II NR III NR IV NR V