Managing pluvial resources and improving soil hydrology: Survival questions for cotton farming systems. The case study of the Mouhoun (Burkina Faso)

Abstract

Cotton cropping has been developing for more than 40 years in the western part of Burkina Faso. It has made a definite modernization of the traditional farming system. Modernization is illustrated by adoption of specific agricultural practices like monoculture, tillage, straight sowing and slope ridge planting. Misuse and non-adaptable local pedologic and climatic context of these new practices perturb soil hydrological processes. Outcomes are water loss by runoff, erosion and changes in the soils physical and physiochemical properties. Besides, we can notice in this area for more than 30 years climatic changes which require us to ask ourselves what are the resulting consequences. In fact, these climatic changes generate an extension of the rainy season, an increase in the frequency of high intensity spells but also recurrence of dry spells during the rainy season. Do these new climatic conditions exacerbate the consequences of cotton practices on hydrological processes and induce an aggravation of flow and erosion processes? These evolutions have direct consequences on crop production whereas needs are highly increasing. The improvement of the prevailing agricultural practices and innovative practices might provide improved pluvial resources in critical moments such as rainfall excess at the beginning and the end of the rainy season and short drought conditions after sowing or germination and during flowering. However two questions arise. In the rainfed agriculture, which cultural practices (to reduce runoff and to favour infiltration) are, in regard to pedologic, climatic or socio-economic context, able to allow improved water efficiency and, as a result, an increase of the food grains production? Might selected practices and production addition satisfy requirements of the coming population?