How much can sustainable intensification increase yields across South Asia? a systematic review of the evidence

Abstract

Food security will become increasingly challenged over the coming decades, and sustainable intensification is often touted as an ideal way to increase yields while limiting negative environmental impacts. Yet, the extent to which sustainable intensification can increase yields remains unclear. We systematically reviewed the literature to assess the extent to which sustainable intensification can increase yields across South Asia, a region that is expected to face some of the greatest food security challenges over the coming decades. We found that yield gains from sustainable intensification interventions were heterogeneous, and that the average yield gain across all studi es was 21%. Residue retention and the use of organic fertilizers were, in particular, associated with significant and positive yield gains, though the use of organic fertilizers was not always profitable, likely due to large subsidies provided for mineral fertilizers across South Asia. Our work also revealed biases in the current sustainable intensification literature, with research clustered in highly productive, irrigated, and commodity cropping systems, which do not represent large portions of agricultural systems across South Asia. Our results highlight that sustainable intensification interventions should play an important role in increasing food production across South Asia, but yield gains from these interventions are modest compared to estimated yield gaps across the region.

Keywords

• sustainable intensification
• South Asia
• yield gaps
• grain crops
• systematic review