| 刘琳,李普旺,徐明岗,马海洋,杨学云,张树兰.土壤肥力及施氮水平对有机氮组分及氮矿化的影响[J].农业环境科学学报,2026,45(2):446-455. |
| 土壤肥力及施氮水平对有机氮组分及氮矿化的影响 |
| Effects of soil fertility and N application rates on soil organic N components and N mineralization |
| 投稿时间：2025-03-18 修订日期：2025-06-04 |
| DOI：10.11654/jaes.2025-0255 |
| 中文关键词: 冬小麦 产量 氮素供应 氮素利用率 酸解氨基酸态氮 |
| 英文关键词: wheat yield N supply N use efficiency acid-soluble amino N |
| 基金项目:山西省基础研究计划青年项目（202302021222272） |
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| 摘要点击次数: 589 |
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| 中文摘要: |
| 为探明土壤肥力及施氮水平对有机氮组分及土壤供氮能力的影响，优化氮肥施用，提高氮素利用效率，本研究在26 a塿土长期肥料定位试验处理土壤上设置氮梯度微区试验，探究5个不同肥力土壤（F1~F5）及5个施氮水平对冬小麦产量、地上部氮移出量、土壤有机氮组分及表观氮素矿化量的影响，并探讨了表观氮素矿化量与有机氮组分的关系。结果表明：低肥力土壤上小麦产量和地上部氮移出量随施氮量增加而显著增加，而高肥力土壤上增施氮肥对小麦产量和地上部氮移出量均没有显著影响。土壤有机氮以酸解氮为主，土壤肥力水平的提升增加了土壤酸解氮（TNex）含量（691.07~901.81 mg·kg-1），但降低了其占全氮比例（61.24%~78.57%），提高了非酸解氮（NHH）含量（221.46~587.38 mg·kg-1）及其占全氮比例（21.43%~38.76%）。随土壤肥力水平提高酸解未知氮（HUN）含量显著降低，其他各酸解有机氮组分含量显著提高，其中以酸解氨基酸态氮（AAN）增幅最大。除AAN占TNex比例随土壤肥力提升而提高外，酸解氨态氮（ANN）和 HUN占 TNex的比例均随土壤肥力提升而降低。低肥力土壤（F1、F2）有机氮组分以 HUN 为主，占比为 33.92%~40.39%，而高肥力土壤（F3、F4和 F5）有机氮组分以 AAN 为主，占比为 25.72%~35.54%。随机森林模型预测各有机氮组分对氮矿化量变量重要性的结果表明，AAN对表观氮素矿化量的相对重要性最高，后者随前者增加而显著增加；其次为 TNex。研究表明，不同肥力土壤有机氮组分及其比例存在显著差异，短期施氮对有机氮组分没有显著影响；土壤肥力水平改变土壤氮素供应能力主要与AAN有关。当土壤AAN含量分别为494 mg·kg-1和439 mg·kg-1时，小麦籽粒产量和地上部氮移出量最高。 |
| 英文摘要: |
| To investigate the effects of soil fertility and fertilizer N application rates on organic N components and soil N supply capacity, optimize fertilizer N application and improve N use efficiency. Based on a N gradient micro-plot experiment established on plots subjected to various fertilization treatments for 26 years at a Loess soil, we systematically explored the wheat yield, above-ground N uptake, soil mineral N and organic N fractions under five soil fertility levels and at five N application rates, and aimed at established the correlation between organic N components and N mineralization. The result showed that the grain yield of winter wheat and N uptake of above-ground biomass significantly increased with increasing N application rate on low fertility soil, but showed no response to N rate on high fertility soil. Acid-soluble N（TNex）is the major form of soil organic N. The improvement of soil fertility level increased TNex content（691.07- 901.81 mg·kg-1）, but decreased its proportion to total N（TN, 61.24%-78.57%）, and increased the acid non-soluble N content（NHH, 221.46-587.38 mg·kg-1）and its proportion to TN（21.43%-38.76%）. With the increase of soil fertility level, the content of acid-soluble hydrolysable unidentified N（HUN）was significantly decreased, and other organic N contents were significantly increased, especially so for the acid -soluble amino N（AAN）. The proportions of ANN and HUN to TNex decreased with increasing soil fertility, whereas the proportion of AAN to TNex showed a concurrent increase with soil fertility levels. HUN was the main organic N fraction in low fertility soil （F1, F2）, varying from 33.92% to 40.39%, while the major organic N fraction of high fertility soils（F3, F4 and F5）was AAN, ranging from 25.72% to 35.54%. The results of the Random Forest model showed that AAN had the highest relative importance for the apparent N mineralization, followed by the TNex, and that apparent N mineralization increased significantly with increasing AAN. N application rate had no significant effect on organic N components, but soil fertility level changed the distribution characteristics of organic N components in soil, and soil N supply capacity was mainly related to AAN. When soil AAN content arrived 494 mg·kg-1 and 439 mg·kg-1, wheat grain yield and above-ground N uptake maximum. |
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