The effect of crop residues management on crops yields and nutrients balances in a cotton-cereals cropping system was studied in a long-term experiment carried out from 1982 to 2006. The experimental design was a simple nonrandomized blocks comparing extensive management of crops residues (T1), semiintensive management of crops residues (T2) and intensive management of crops residues (T3). Crops yields, soil chemical properties and mineral balances were measured. Results showed that after 25 years, soil carbon contents decrease was respectively 44%, 15% and 13%, with an extensive, semi-intensive and intensive management of crops residues. Total phosphorus decrease was 25% in all the treatments. Exchangeable Ca and Mg declined from 2.43 to 1.37 cmol+ kg -1 and 0.9 to 0.29 cmol+ kg -1 respectively while the Sum of Exchangeable Bases declined from 3.79 to 1.79 cmol+ kg -1. Recycling crops residues to compost and manure increased cotton yields from 13 to 22%, maize yields from 45 to 60%, and sorghum yields from 19 to 44%. Mineral balance in N, P, K and S was improved after 25 years of continuous cultivation while using compost or manure. At the same time, the decline of soil properties was due to nutrients losses which need to be evaluated. This study recommends integrated crops residues management and the use of rock phosphate to improve sustainability in cottoncereals cropping systems.
