The impact of conservation agriculture on smallholder agricultural yields: A scoping review of the evidence

The benefits of conservation agriculture (CA) are widely promoted, yet there is uncertainty about the efficacy of CA for increasing yields in the context of smallholder agriculture. This paper seeks to understand the state of current research on the question “What are the impacts of CA on agricultural yields?” by meeting two objectives: (1) review the methodologies and rigor of previous literature analyses on this subject and evaluate their relevance to CA adoption in the context of smallholder agriculture, and (2) assess the scope and quality of empirical evidence from the target region and identify knowledge gaps. Existing literature reviews compared unfavorably against the criteria utilized in the analysis. In examining empirical evidence of CA impacts on crop yields, the authors encounter a lack of rigor in agronomic research that inhibits meta-analysis of the data and recommend a minimum dataset requirement for research addressing the agronomic impacts of CA. Other recommendations for future research include the use of geographic referencing and implementation higher quality survey methods and instruments. In order for this research to be useful, the authors suggest the development of a repository to house agronomic and survey datasets and support conducting systematic reviews and meta-analysis of the data. They propose that peer-reviewed journals and sponsoring organizations must take a greater role in data stewardship.