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作 者 ：刘新宇, 巨晓棠, 张丽娟, 李鑫, 袁丽金, 刘楠

期 刊 ：植物营养与肥料学报 2010年 16卷 2期 页码：296-303

关键词：冬小麦；氮去向；氮素平衡；15N；

Keywords:winterwheat, fateofN, balanceofN, 15N,

摘 要 ：采用田间微区¹⁵N示踪技术，研究了冬小麦季化肥氮去向及土壤氮素平衡。结果表明，在供试土壤肥力水平和生产条件下，N 150 kg/hm²的施肥量已达到较高产量，再增加氮肥用量小麦产量不再增加。随着施肥量的增加，地上部吸氮量有所增加，氮肥的表观利用率和农学利用率持续下降，而生理利用率则表现为低—高—低的变化趋势。在低施氮条件下，小麦主要吸收土壤氮的比例高于化肥氮； 在高施氮条件下，小麦吸收土壤氮的比例下降。冬小麦收获后，仍有26.7%～40.6%的氮肥残留在0—100 cm土层中，17.4%～24.8%的氮肥损失。残留在土壤剖面中的氮肥主要分布在表土层。随着施氮量的增加，土壤氮素总平衡由亏缺转为盈余； 土壤根区硝态氮也由播前消耗转为在播前的基础上累加，两个小麦品种表现为相同的趋势。

Abstract:The fate of N fertilizer and balance of soil N under winter wheat farming were studied using filed¹⁵N micro-plot. The results show that crop yield would not increase when the nitrogen application rate is above N 150 kg/ha. Apparent recovery efficiency and agronomic efficiency of nitrogen fertilizer are constantly decreased with increasing of rate of nitrogen fertilizer, while the trend of physiological efficiency is low-high-low. At lower N rate, more soil N is absorbed by winter wheat than that from fertilizer N, and the ratio of soil N absorption to fertilizer N absorption is decreased under high N application. After the harvest of winter wheat, 26.7%-40.6% of fertilizer N is resided in 0-100 cm, and 17.4%-24.8% of fertilizer N is lost. With increasing of nitrogen fertilizer application, the total balance of soil N is from deficiency to surplus, and NO^-₃-N in the root zone soil is from consuming nitrogen to cumulating nitrogen before seeding. There is similar trend between two wheat varieties.

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