Cassava-legume intercropping is more beneficial in low-input systems: A meta-analysis

Cassava-legume intercropping is widely practiced throughout the tropics. This meta-analysis analyzed the results of 55 publications from 1979 to 2021 containing 501 cassava-legume intercropping treatments to determine the average yield benefit of the practice and to identify management practices that modulate the effect of intercropping. Overall, cassava-legume intercropping was found to be beneficial in terms of land equivalent ratio (mean LER = 1.557), particularly combinations with peanut, cowpea, or soybean. In contrast, cassava-pigeon pea intercropping was not beneficial and produced LER values below 1. The yield benefit of intercropping was significantly lower in fertilized and irrigated systems (LER = 1.131) than in unfertilized rainfed systems (LER = 1.587), likely due to increased competition from cassava that received fertilizer and irrigation. These results support the stress gradient hypothesis and underline the need for management practices and improved varieties specifically optimized for cassava-legume intercropping.