Sustainable cotton production systems for the humid savannas of central Brazil

Most Brazilian cotton is produced in the Cerrados, i.e. the humid savannas of Central Brazil. In this frontier region, a very dynamic and powerful agriculture is driven by the search for short term economic returns despite the absence of subsidies. Highly mechanized formers first introduced largescale monocultures dominated by soybean, More recently, cotton has become an attractive cash crop, despite difficult natural and economic conditions, resulting in irregular returns. Furthermore, the domination of monocultures, the use of disc tillage and high levels of inputs have resulted in soil and environmental degradation and less sustainable production systems. CIRAD, Brazilian research institutes, and various private partners (Maeda, Coodetec, Agronorte) have joined forces to find solutions resulting in significant and regular decreases in production costs while preserving soil fertility and the environment. Crop rotations, direct seeding under cover crops, and varietal testing within the most performing cropping systems, using a participatory approach, constitute the most promising avenues to achieve these objectives. This method, known as innovation-extension, allows the best producers to reach yields ranging from 3000 to more than 5000 kg/ha of seed cotton, while constantly increasing fiber quality, reducing production costs and risks and minimising the impact on the environment. (Résumé d'auteur