Mulch cover does reduce runoff in cotton fields in West Africa cotton fields, but does not improve cotton yields

In the Sudano-Sahelian zone of West Africa, crop productivity is frequently negatively affected by water shortage. The cotton crop, although tolerant to water stress, is affected by water shortage, especially at the beginning of its cycle for emergence and early growth. The use of crop residues of the previous cropping season as mulch cover could be a way to improve its water balance at the beginning or at the end of the rainy season by reducing runoff (Giller et al., 2009). To test this hypothesis, we compared the conventional cropping system and a cotton crop sown in the residues of the previous Sorghum/Brachiaria associated crops, for soil water content and yield.