A new study published in Nature Sustainability has drawn together data from 1,353 field studies across South Asia, to explore how conservation agriculture (CA) performs against conventional cropping practices in the region. From a total sample of 9,686 paired site-year comparisons, it confirms that there are significant benefits to yield (6%), water use efficiency (13%), net economic returns (26%); and a reduction in emissions (12 – 33%) when using CA approaches. Data from the Sustainable and Resilient Farming Systems Intensification (SRFSI) project, previously published in the Journal of Cleaner Production, was included in the study. SRFSI results correspond well with those from the wider study.
CA is based on the linked principles of minimising or eliminating soil disturbance; retaining residue in-situ; and diversifying cropping systems. Importantly, this study showed that these significant benefits are maintained when the component practices of CA are implemented either separately or in tandem. There are variations among crops, cropping systems and soil types. Better effects were found when both cereals had zero tillage, and with residues retained in one or both the crops across the cropping system. Greater economic benefits (40% increase) come from using all CA principles in the cropping system (i.e. all crops established with zero till conditions, and all residue retained) compared to only one or two components implemented (20 – 26% increase).
This study importantly shows that the benefits of even partial adoption of CA can be beneficial in the South Asian context. There is a need for a pragmatic approach to scaling CA, where it is often not practical in the context of small and diverse farming systems to implement full CA systems; and so relevant practices should be promoted accordingly.
For more information, please contact Dr Mahesh Gathala ([email protected]).