Temporal yield stability of cereal-cereal and cereal-legume intercropping. A meta-analysis

Abstract

Sustainably producing sufficient food for a growing population is a major challenge, as intensive monocultures are highly vulnerable to climate change, pests, and disease outbreaks. Intercropping offers a promising alternative, improving land productivity while delivering multiple ecological benefits. However, the effect of intercropping on temporal yield stability remains poorly understood, and how this stability is affected by different management practices remains uncertain. To address this gap, we conducted a meta-analysis of 511 records from 94 experiments across 45 publications on the effect of intercropping on temporal yield stability, taking into account a wide range of management practices. Temporal yield stability was measured by two metrics, i.e., the coefficient of variation of yield across years, and the yield loss during “poor years” (i.e., years characterized by below-average yields). At the intercropping system level, the values of coefficient of variation in intercropping and monocropping were similar when all types of intercropping were considered together, but yields were significantly more stable in cereal/cereal (8.3%; 95% CI: 4.6–12%) than in cereal/legume intercropping (12.2%; 95% CI:9.11-15.24%). Legumes showed reduced yield stability in intercropping versus monocropping, whereas cereals maintained similar stability across monocropping, cereal/legume, and cereal/cereal systems. Yield gains and temporal stability in intercropping correlated positively, driven by higher land equivalent ratio and net yield effect. Nitrogen input increased yield stability in both intercropping and monocultures. Here we show for the first time that intercropping can increase crop productivity while maintaining yield stability comparable to that of sole cereals, with cereal/cereal intercropping providing an optimized option for maximizing yield without compromising temporal stability in resource-rich systems, and cereal/legume intercropping supporting sustainable production under low-input conditions. However, the yield stability of legumes in intercropping is low compared to monocropping, indicating a need for further research to improve legume varieties and associated management practices.