Abstract Crop residue incorporation is an effective agricultural management to enhance soil organic carbon and nitrogen (N) sequestration, which inevitably affects the crop N uptake, and consequently the allocation of N in the soil-plant system. However, to what extent the crop residue type and soil fertility moderate the contribution and recovery of maize (Zea mays. L) residue-derived N (residue-N) in the soil-plant system is poorly understood. Therefore, a 2-year in situ experiment was conducted on an Alfisol with high fertility (HF) and low fertility (LF), along with the application of 15N-labeled maize root or straw (both stem and leaf) residues. The results showed that the HF treatment had a smaller proportion of residue-N in total N uptake compared with the LF treatment (on average of 2.0% vs. 3.6%), but with a larger recovery rate (on average of 23.5% vs. 12.8%). The application of straw residues increased the proportion of residue-N in plant total N compared with that from the application of root residues in the HF treatment. The percentage of residue-N in total soil N (TSN) and the residue-N recovery in the LF soil were 60.7–108.5% and 9.6–25.8% higher than those in the HF soil, respectively. The proportion of root-derived N (root-N) in TSN was significantly higher than that of straw-derived N (straw-N) in the LF soil. In addition, total residue-N recovery rates were similar among all residue-amended treatments. The results indicated that the soil with high fertility could increase residue-N utilization by plant, especially the straw-N, while the soil with low fertility favored the accumulation of the residue-N in soil, especially the root-N, and its low fertility was more likely to be improved. Overall, soil fertility and residue type could significantly affect the allocation of maize residue-N in the soil-plant system.

中文翻译：

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土壤肥力对土壤-植物系统中不同玉米残留部位氮素分配的影响

摘要 作物残茬掺入是提高土壤有机碳和氮（N）固存的有效农业管理方式，不可避免地影响作物对氮的吸收，进而影响土壤-植物系统中氮的分配。然而，作物残留物类型和土壤肥力在多大程度上调节了土壤-植物系统中玉米（Zea mays.L）残留物衍生氮（residue-N）的贡献和恢复尚不清楚。因此，在具有高肥力 (HF) 和低肥力 (LF) 的 Alfisol 上进行了为期 2 年的原位试验，同时应用了 15N 标记的玉米根或秸秆（茎和叶）残留物。结果表明，与 LF 处理相比，HF 处理在总氮吸收中的残留 N 比例较小（平均 2.0% vs. 3.6%），但回收率更高（平均 23.5% 对 12.8%）。与HF处理相比，秸秆残留提高了植物总氮中残留-N的比例。LF 土壤中残留氮占土壤总氮 (TSN) 的百分比和残留 N 回收率分别比 HF 土壤高 60.7-108.5% 和 9.6-25.8%。TSN中根源性N（root-N）的比例显着高于LF土壤中秸秆源性N（straw-N）的比例。此外，所有残留修正处理的总残留氮回收率相似。结果表明，肥力高的土壤可以增加植物对残留氮的利用，尤其是秸秆氮的利用，而肥力低的土壤有利于土壤中残留氮的积累，尤其是根系N，其低肥力更有可能得到改善。总体而言，土壤肥力和残留物类型可显着影响土壤-植物系统中玉米残留物-N的分配。