Evolution of Draft Animal Power Practices and Consequences on Crop Systems Sustainability

In West and Central Africa savannah zone crop systems, draft animal power plays a major role by providing farmers with increased intervention means during key steps of the agricultural calendar: ploughing, seeding, weeding, transport. In the past ten years, three factors led to practices evolution: i) dismantling public agricultural services made purchasing and maintaining animal teams more difficult; ii) land pressure increase in rural zones reinforced crops and livestock integration, and induced practices based on work intensification (mechanized weeding...); iii) broad use of herbicides resulted in ploughing decline. Agronomic consequences of these changes on crop systems sustainability are sometimes positive (more work flexibility; production, and household income increases) and sometimes negative (marginal role of animal husbandry in fertility transfers, degradation of mechanical seeding, degradation of crop management sequences, deforestation...). Various ways to improve the technique of animal traction are proposed.