【摘要】 【目的】探究不同氮水平与间作大豆对甜玉米土壤团聚体稳定性及有机碳含量的影响，为优化甜玉米//大豆带状复合种植技术体系、实现氮肥减量增效和农田固碳减排提供科学依据。【方法】依托甜玉米//大豆间作长期定位试验研究了施氮水平（N0-不施氮，N1-减量施氮300 kg/hm~2和N2-常规施氮360 kg/hm~2）和种植模式（SS-甜玉米单作、S2B3-甜玉米//大豆2∶3间作和S2B4-甜玉米//大豆2∶4间作）对甜玉米产量、土壤团聚体以及有机碳含量的影响。【结果】施氮显著提高了甜玉米产量并降低了土地当量比，N1和N2处理的降幅分别为11.30%～14.59%和9.66%～10.73%，但减量施氮和常规施氮间无显著差异；施氮促进粗大团聚体（>2 mm）分解为细大团聚体（0.25～2 mm），显著降低甜玉米土壤团聚体稳定性、原土及各粒级团聚体有机碳含量和粗大团聚体有机碳贡献率。总体上，间作对土壤团聚体稳定性、原土及团聚体土壤有机碳含量无显著影响；但S2B3模式有提高甜玉米土壤团聚体稳定性的趋势，且在N0处理下S2B3处理的土壤有机碳含量显著高于其他处理。【结论】施氮显著降低了甜玉米//大豆间作系统土壤团聚体稳定性及有机碳含量，减量施氮与甜玉米//大豆2∶3间作在维持甜玉米产量稳定的同时有提高土壤团聚体稳定性和有机碳固持的潜力。更多还原

【Abstract】 【Objective】The aim of this study to explore the effects of different nitrogen (N) levels and sweet maize//soybean intercropping patterns on soil aggregate stability and organic carbon (C) content in sweet maize,aiming to provide a scientific basis for optimizing the sweet maize//soybean strip intercropping system,and thus achieving N fertilizer reduction and efficiency increasing,and promoting C sequestration in agricultural ecosystem.【Method】In this study,a long-term field experiment was conducted to investigate the effects of N levels (N0-no nitrogen,N-reduced nitrogen dose of 300 g/hm~2 and N2-conventional nitrogen dose of 360 kg/hm~2) and planting mode (SS-sweet maize monocropping,S2B3-sweet maize//soybean 2∶3 intercropping and S2S4-sweet maize//soybean 2∶4 intercropping) on sweet maize yield,soil aggregates and organic C content.【Result】Nitrogen application significantly increased sweet maize yield but reduced the land equivalent ratio (LER) by 11.30%-14.59%and 9.66%-10.73%for N1 and N2,respectively.Notably,there was no significant difference of sweet maize yield and LER between N1 and N2.Nitrogen application promoted the decomposition of large macroaggregates(>2 mm) into small macroaggregates (0.25-2 mm),which significantly reduced the stability of sweet maize soil aggregates,as well as organic C content of bulk soil and aggregates,and the organic C contribution rate of large macroaggregates.In general,intercropping had no significant effect on soil aggregate stability,and soil organic C content of bulk soil and aggregates.However,the S2B3 treatment appeared to improve the stability of sweet maize soil aggregates compared with other treatments.Furthermore,when no N was applied,soil organic C content in S2B3 was increased by 10.48%(P<0.05) compared with SS.【Conclusion】Nitrogen application significantly reduced soil aggregate stability and organic C content in sweet maize//soybean intercropping system,reduced N application and S2B3 intercropping showed the potential to improve soil aggregate stability and organic C sequestration,and meanwhile ensure the stable sweet maize yield.更多还原