Impact of conservation agriculture and biochar interventions on labour demand and productivity in Uganda: evidence from a field experiment

Résumé fourni par la source

Abstract Conservation agriculture (CA) and the use of biochar as a soil amendment can promote productive, resilient, and sustainable smallholder farming. However, adopting these practices requires a shift from conventional methods, potentially changing labour use and returns, the extent of which remains poorly understood. Using data from a randomized controlled trial (RCT) of 400 farmers designed to be representative of smallholder farmers in two districts of Uganda, this study assesses how an informational intervention (delivered through instruction and participatory field demonstrations) on CA methods with and without biochar affect labour use and productivity. Control group farmers were compared to those receiving (i) CA and (ii) CA+BIOCHAR interventions. First difference and inverse probability–weighted regression-adjustment model results indicate that the CA+BIOCHAR intervention increased labour use, with no significant labour productivity gains, compared to the control group. Labour input rose by about 36%, driven by a 54% increase in family labour, while hired labour input declined. Extra work was hence met by family labour rather than paid work. Labour savings occurred only in land preparation, and overall returns to labour were roughly 45% lower than conventional practice. The shifts in labour use and productivity are largely attributable to the information intervention, which increased cultivated area, area under minimum tillage, crop diversity, and biochar application. Taken together, these findings show that, over the study period following the intervention, the promoted CA and biochar package was associated with higher labour demand and no clear labour productivity gains. Bundling training with complementary interventions that tackle the labour burden inherent in smallholder agriculture may be necessary to achieve both labour-saving and labour productivity gains from CA and biochar adoption.