Productivity effects of agroecological practices in Africa: insights from a systematic review and meta-analysis

Abstract

Abstract Scholars have proposed agroecology as a promising method for promoting sustainable and socially just agricultural production systems. However, the extent to which agroecological practices will generate the yields required to ensure sufficient food globally remains unclear. This notion is particularly true in the context of Africa, where agricultural productivity is low but levels of hunger and malnutrition are high. To address this knowledge gap, this article undertakes a systematic review of empirical studies to assess the overall status of agroecology-related research in Africa. Using descriptive and meta-analytical methods, we evaluate empirical evidence on the effect of agroecological practices on land and labour productivity. Our analysis of 501 peer-reviewed articles reveals that the body of agroecology-related literature in Africa has been growing in the past 10 years from approximately 10 to more than 70 studies per annum before and after 2014, respectively, with a strong focus on East Africa, particularly Kenya. The majority of the reviewed studies relate to but do not mention agroecology in the title or abstract. Thus, solely relying on studies that use the term may introduce bias and overlook valuable research contributions to the field. The meta-analysis could identify 39 agronomic studies with 392 observations in which agroecological practices were compared to monocrop systems (defined as plots where similar plants grow alongside each other simultaneously and sequentially from one season to the next) with or without inputs as the control groups. The meta-analysis indicates that agroecological practices are associated with a positive and significant difference in land productivity, compared to that for monocrop systems especially so when monocrops are grown without inputs. However, the size and direction of yield differs by practice, crop, climatic factor, soil property and type of control.