Organic fertilizer and straw return are sustainable measures for increasing crop yield and improving the soil environment. The present study investigated the effects of combined organic fertilizer and straw return on soil nutrient status, soil nitrate–N distribution, and crop productivity in rainfed maize–wheat rotation on the southeast Loess Plateau. Based on a long-term field fertilization experiment, we reported the effects of four fertilizer management strategies (i.e., chemical NP fertilizers [NP, conventional practice]; chemical NPK fertilizers [NPK]; chemical NP fertilizers combined with organic fertilizer [NPOF]; and chemical NP fertilizers combined with organic fertilizer and straw return [NPOFS]) on productivity in summer maize and winter wheat from 2015 to 2020 season and the soil properties in the 0–60-cm soil layer and the soil nitrate–N distribution in the 0–380-cm soil layer at maturity of winter wheat in 2020. The results averaged from 2015 to 2020 showed that NPOFS increased the grain yield of summer maize by 10.34–11.25%, and water use efficiency by 21.44–32.54%, compared with NP, NPK, and NPOF; however, it had no significant effect on winter wheat yield. All four treatments benefited topsoil (0–20 cm) properties, and NPOFS was superior to NP, NPK, and NPOF in increasing the content of soil organic matter, total nitrogen, available phosphorus, and available potassium, in the 0–60-cm soil layer. Meanwhile, compared with NP and NPK, NPOFS significantly increased soil nitrate–N accumulation by 63.22% and 49.87%, respectively, in the 0–100-cm soil layer and decreased by 24.78% and 10.19%, respectively, in the 200–380-cm soil layer. These results suggest that the combination of organic fertilizer and straw return could improve soil fertility and summer maize productivity and significantly reduce nitrate–N accumulation in the 200–380-cm soil layer. Their use should be recommended for coordinated crop productivity and the soil environment in rainfed summer maize–winter wheat rotation on the southeast Loess Plateau.

有机肥和秸秆还田是提高作物产量和改善土壤环境的可持续措施。本研究调查了有机肥和秸秆还田对土壤养分状况、土壤硝酸盐-N 分布和黄土高原东南部雨养玉米-小麦轮作作物生产力的影响。基于长期田间施肥试验，我们报道了四种肥料管理策略（即化学氮磷肥[NP，常规做法]；化学氮磷钾肥[NPK]；化学氮磷肥与有机肥结合[NPOF]；和化学氮肥结合有机肥和秸秆还田[NPOFS]）对2015-2020年夏玉米和冬小麦生产力的影响以及0-60厘米土层土壤性质和土壤硝酸盐-N分布2020年冬小麦成熟期0~380 cm土层。2015~2020年平均结果表明，与相比，NPOFS使夏玉米增产10.34~11.25%，水分利用效率提高21.44~32.54%。 NP、NPK 和 NPOF；但对冬小麦产量无显着影响。四种处理均有利于表层土壤（0-20 cm）的特性，NPOFS 在增加 0-60 cm 土壤有机质、全氮、速效磷和速效钾含量方面优于 NP、NPK 和 NPOF土层。同时，与NP和NPK相比，NPOFS 在 0-100 厘米土层中显着增加了土壤硝酸盐-N 积累量，分别增加了 63.22% 和 49.87%，在 200-380 厘米土层中分别减少了 24.78% 和 10.19%。这些结果表明，有机肥和秸秆还田相结合可以提高土壤肥力和夏玉米生产力，并显着减少 200-380 厘米土层中硝酸盐-氮的积累。应推荐使用它们来协调黄土高原东南部雨育夏玉米-冬小麦轮作的作物生产力和土壤环境。这些结果表明，有机肥和秸秆还田相结合可以提高土壤肥力和夏玉米生产力，并显着减少 200-380 厘米土层中硝酸盐-氮的积累。应推荐使用它们来协调黄土高原东南部雨育夏玉米-冬小麦轮作的作物生产力和土壤环境。这些结果表明，有机肥和秸秆还田相结合可以提高土壤肥力和夏玉米生产力，并显着减少 200-380 厘米土层中硝酸盐-氮的积累。应推荐使用它们来协调黄土高原东南部雨育夏玉米-冬小麦轮作的作物生产力和土壤环境。