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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. [ABSTRACT FROM AUTHOR]

Diversified cropping is a crucial management practice for increasing carbon (C) and nitrogen (N) sequestration in agroecosystems. However, knowledge gaps regarding the mechanisms by which diversified cropping affects C sequestration and soil quality remain unclear. Herein, a field experiment across six-year was performed to explore the effect of three contrasting cropping systems (i.e., winter wheat/summer maize, winter wheat/summer maize-early soybean, and nature fallow) on soil quality and C sequestration, as well as their main drivers at both 0–20 cm and 20–40 cm soil depths. Diversified cropping increased soil organic C (SOC) stock by 9% and the majority of the soil biochemical metrics in the topsoil despite a 40% reduction in the fertilizer application relative to wheat/maize. This was attributed to increased SOC content in large macroaggregates and enhanced microbial turnover due to diverse fresh residue inputs under diversified cropping. Alternatively, the soil organic C, microbial biomass C, C-acquisition enzyme activity, and N-acquisition enzyme activity in large macroaggregates (> 2 mm) were increased by 15%, 15%, 32%, and 16% in the topsoil under diversified cropping versus wheat/maize, respectively. Partial least squares path model displayed that increased C sequestration was mainly driven by microbial biomass C irrespective of the bulk- and aggregate scale. Furthermore, diversified cropping increased the soil quality index by 1- to 2-fold relative to maize/wheat since increased aggregate stability benefited soil structure and nutrient cycling regardless of soil depth. Overall, increased SOC stock is dominantly driven by microbial biomass C, and the improved soil quality is mainly impelled by soil organic C and aggregate stability in responding to diversified cropping were expected to create win-win scenarios for agroecosystems. [Display omitted] • Diversified cropping enhanced the majority of soil metrics in > 2 mm aggregates. • Enhanced C in > 2 mm aggregates determined the SOC stock in diversified cropping. • Increased SOC was mainly driven by microbial biomass irrespective of the bulk- and aggregate scale. • Soil quality was increased 1.1–2.0 times under diversified cropping as driven by SOC and aggregate stability. [ABSTRACT FROM AUTHOR]