Soil conservation is a set of practices used to enable sustainable use of soil, whether in agriculture, livestock or forestry,. It aims both to prevent soil loss due to erosion and to reduce fertility due to excessive use or contamination of the soil.
The consequences of burning, deforestation and other unsustainable methods of subsistence agriculture are large-scale erosion, with the loss of soil nutrients up to and including total desertification.
Techniques to improve soil conservation are:
- Maximum soil cover, by residues from previous crops (called mulch) or by cover crops planted as intercrops or permanent living cover
- No turning of the soil by ploughing and a significant reduction or even elimination of tillage
- Extension and diversification of crop successions, through the alternation of plant families (legumes, cereals, cruciferous plants) and the use of intermediate crops and crop associations.
In Africa, soil conservation agriculture is progressing slowly in about 15 countries and on relatively small areas. In general, there is a partial application of the tripod.
Permanent coverage has been practiced since 1920 in Nigeria with a legume, the Mucuna pruriens. Technique successfully repeated in Benin. Zero tillage systems are developing in Ghana, but without permanent soil cover. We note the use of herbicides on cotton crops in northern Cameroon.