Legume-based rotation enhances subsequent wheat yield and maintains soil carbon storage

Legume inclusion into cropping systems has been proposed to maintain high crop yields while offering multiple environmental benefits. However, the effect of legumes as pre-crop on subsequent wheat yield and soil has not been well explored. Thus, a 7-year field experiment was used to determine the interactive effects of mineral fertilization and legumes (peanut, mung bean, soybean, adzuki bean) inclusion on wheat productivity and soil quality. Our results showed that legume inclusion led to a higher wheat yield advantage (52% on average) than maize-wheat rotation under no fertilization but the advantage decreased to 26% with fertilization. All legume-wheat rotation systems supported stable wheat production, where a stronger effect was observed after peanut than after maize. Meanwhile, the wheat yield under legume-wheat systems was more resistant (i.e., less variability in the yield after ceasing fertilization) and more resilient (i.e., recovering more quickly after fertilizer re-application) relative to maize-wheat. Furthermore, soil ecosystem multifunctionality increased by 0.8 times in the topsoil while maintaining soil organic carbon stocks, even with low C and N inputs under legume-wheat. Interestingly, we also observed a positive correlation between wheat yield and soil ecosystem multifunctionality. In conclusion, legume inclusion as a sustainable practice can optimize crop yields by enhancing soil multifunctionality while maintaining soil organic carbon stocks, particularly for integration into low-yielding agroecosystems.