Advantages of cover crops:
- contribute to soil nutrients which are then made available to growing crops;
- increase soil fertility;
- improve soil structure;
- reduce soil erosion;
- reduce weed pressure;
- contribute to breaking pest and disease cycles;
- trap nutrients; and
- increase the organic matter in soil.
Cover crops can be used for the following purposes:
- As mulch material;
- In rotation with primary crops to break the negative effects of mono-cropping;
- Grown on resting lands to improve soil health;
- Inter-cropped with primary crops as a living mulch;
- Used as relay crops by being planted while primary crops are still in the ground.
Recommended cover crops include sunn hemp, black oats, velvet beans, dolichos beans, cow peas, forage sorghum, dry beans, soya beans, clovers, chick peas, buckwheat, black oats, white oats, stooling rye, barley, wheat, lupins, lucerne, teff, rye grass, and vetch.
Cover crop seeds are usually broadcast-planted onto the soil surface at a rate of about 50kg/ ha (about 5g/m2.). Currently, costs range from around R500/ ha to R1 200/ha.
Despite their many benefits for CA, cover crops should not be considered a total or quick-fix solution for improving soil health or generating high yield of primary crops. They are among the many good and sustainable agricultural practices available.