A Guide to Conservation Agriculture in Zimbabwe - Canadian ...

section ONE
Promoting Conservation Agriculture Among Farmers
Improves nutrition available to households
Conservation agriculture, if practised correctly, has the
potential to improve food security and nutritional status
for farming households. Firstly, higher yields will provide
more food for the family to eat directly, and any surplus
can be sold and the cash used to buy other dietary
requirements. Secondly, by establishing the practice of
intercropping or rotating with legumes, households
benefit from a mixed diet.
Increases profit and return to labour
Recent enterprise budget analysis for planting basins and
farmer practice in Masvingo showed that costs per tonne
of maize are around three to four times lower for
conservation agriculture compared to conventional
farming. Returns to labour increased five-fold for farmers
using planting basins for the first time. This is the case
even though conservation agriculture usually requires
more labour than farmer practice as well as the application
of basal fertilizer and top dressing which farmer practice
normally excludes.
Long-term benefits (beyond 4 years)
Improves soil fertility
Conservation agriculture principles such as applying soil
cover, combining cereal-legume associations and applying
organic and inorganic fertilizers help build soil fertility.
Soil cover results in organic matter build up, which
increases the population and activity of macro and micro
soil organisms. This results in more humus formation as
soil micro-organisms break down the organic matter,
yielding a dark coloured soil. Inclusion of fertility
amendments and legumes replenish soil nutrients, and
macro-organisms such as worms and termites burrow
into the soil, improving its structure, enabling good root
formation and drainage.
Stabilises yields
Conservation agriculture systems achieve high yield levels
with fewer fluctuations than conventional ploughing,
even in poor seasons. Conservation agriculture therefore
contributes to food security at household and national
level. Crop rotations and crop mixes produce a range of
crops. They reduce the risk of ruin if one crop fails, and
provide a more diverse diet.
Reduces weeds
Reduced tillage disturbs the soil less and so brings fewer
buried weed seeds to the surface where they can
germinate. Weed seeds and or weed seedlings on the soil
surface are suppressed by the presence of mulch. Timely
weeding results in fewer weed seeds being deposited on
and in the soil.See pictures below.
No mulch spread: More weeds appear because there is no suppression
and shade effect
Mulching between basins: Fewer weeds because of mulch effects
15 Farming for the Future