In the semi-arid zones of West Africa, the relationships between organic matter management methods, soil quality who has resulted and cotton production, remains little or poorly known. In a simple non-randomized block design located at Boni in western Burkina Faso, we studied the impact of three organic matter management methods on soil quality and cotton yield over a period of thirty years. The three modes of crop residue management compared were: extensive management, where residues are exported (SI); semi-intensive management (SII); and intensive management of crop residues (SIII), corresponding to compost and recycled manure inputs respectively. The results showed that, over time, cotton yields and rainfall fluctuated almost identically, whatever the crop residue management method. In terms of soil chemical properties, compost (7.16 g.kg-1) and manure (6.75 g.kg-1) reduced the degradation of soil fertility compared with the initial soil (7.70 g.kg-1). Investigation into the determinants of cotton production at farm level showed that the factors controlling cotton yield are major elements (C, N, Pas and Kt), exchangeable bases (Ca2+, Mg2+, Na+ and K+) and CEC. Regardless of how soil fertility is managed, cultivation has led to a decline in soil fertility. This study served as a reminder of the benefits of good agricultural practices for sustainable soil fertility management.

Low crop yields are often explained by unfavourable rainfall conditions, the natural poverty of the soil in terms of nutrients and the low use of fertilisers. In order to find appropriate solutions for the sustainable management of soil fertility, a study was carried out on the Fertility Maintenance Trial (FTM), an experimental system established in 1960 in central western Burkina Faso, where organic and/or mineral fertilisation regimes combined with crop rotations have been tested. The approach of this study consisted of a synthesis of existing agronomic data from 2011-2019 on the three (03) crop rotations. Soil samples were taken from a depth of 0-20 cm for physico-chemical analysis. We also measured yields on the cotton and sorghum plots during the 2018 and 2019 seasons. The results show that yield variability can be attributed not only to fertilisation, but also to crop rotations and the annual rainfall recorded over the period. The sorghum-cotton and sorghum-cowpea rotations produced the highest average sorghum yields, at 547 kg.ha-1 and 642 kg.ha-1 respectively. Sorghum monoculture recorded the lowest sorghum production. Chemical analyses revealed higher phosphorus use in the sorghum-cowpea rotation compared with the other rotations. The study of cropping system efficiency also revealed the role of legumes in crop rotations in maintaining and preserving soil fertility. In addition, we recommend integrated soil fertility management (organic and mineral fertilisation, crop rotations, etc.) for sustainable management of productive capital on cotton farms in Burkina Faso.