Conservation agriculture for sustainable intensification in South Asia

Agriculture's contribution to the Sustainable Development Goals requires climate-smart and profitable farm innovations. In the past decade, attention has been given to conservation agriculture as a 'sustainable intensification' strategy, although a lack of evidence-based consensus on the merits of conservation agriculture prevails in the context of intensive smallholder farming in South Asia. A meta-analysis using 9,686 paired site-year comparisons representing different indicators of cropping-system performance suggest significant (P < 0.05) benefits when conservation-agriculture component practices are implemented either separately or in tandem. For example, zero tillage with residue retention had a mean yield advantage of 5.8%, a water use efficiency increase of 12.6%, an increase in net economic return of 25.9% and a reduction of 12-33% in global warming potential, with more-favourable responses on loamy soils and in maize-wheat systems. Results suggest that there are opportunities to maximize expected benefits, and policymakers and development practitioners should continue to be appraised of the potential of CA for contributing to the Sustainable Development Goals in South Asia. Conservation agriculture prioritizes soil health and diverse cropping systems. This meta-analysis finds multiple benefits, including for water conservation and profitability, from conservation-agriculture practices in South Asia.