Sustainable Intensification Through Conservation Agriculture: Identifying Pathways to Climate Resilient Cropping Systems in Southern Africa.

Smallholder traditional cropping systems in southern Africa are challenged by soil fertility decline, low crop productivity, and negative effects of climate variability and change. Since 2004, there have been a series of initiatives in southern Africa to increase the resilience of current farming systems through conservation agriculture (CA). This crop management systems aims to replace extensive tillage with no-tillage, monocropping with crop diversification, and crop residue removal or burning with surface retention as mulch. Data from long-term research in Malawi, Mozambique, Zambia and Zimbabwe show that CA systems can effectively overcome seasonal dry spells, maintain high levels of infiltration and maintain or increase productivity compared with conventional systems. An analysis of eight CA systems across four countries showed that in 76% of all cases, CA was superior to conventional tillage. However, benefits became only significant after three to five cropping seasons. The results further showed that the combinations of several climate smart technologies (i.e. water efficient cropping systems and stress-tolerant maize germplasm) can yield greater benefits in drought situations than either germplasm or CA alone. Given the multifaceted constraints to sustainable intensification in southern Africa, there is urgent need to identifying strategies and entry points for sustainable intensification into current farming systems. A stepwise approach to gradually introduce components of CA is therefore proposed which will steadily increase food security and livelihoods of farmers.