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作 者 ：曹兵^1,2;贺发云¹;徐秋明²;蔡贵信¹

期 刊 ：应用生态学报 2006年 17卷 10期 页码：1839-1844

关键词：番茄；

摘 要 ：采用田间小区和微区试验，研究了施用化学氮肥对南京郊区菜地番茄产量、氮肥去向及氮素损失的影响.结果表明, 由于土壤和有机肥供氮充分，氮肥施用未增加番茄产量.用差值法计算得到的氮肥利用率在14.5%～22.5%之间.¹⁵N标记尿素微区试验表明，施入氮量的16.6%～28.8%被作物吸收，氮素总损失为34.2%～46.0%.施用化学氮肥增加了土壤剖面中的硝酸盐含量，番茄收获时，10%～10.2%的标记尿素被淋洗到40 cm以下土层.增施化学氮肥也显著增加了菜地土壤的反硝化损失和N₂O排放，其中反硝化损失占施入氮量的5.50%～6.01%；N₂O排放量占施入氮量的2.62%～4.92%.但番茄生长期间未检测到氨挥发.减少氮肥用量或施用包衣尿素可降低菜地施用氮肥的环境风险，特别是减少硝酸盐淋洗和硝化反硝化损失.

Abstract:Field plot and micro-plot experiments were conducted to investigate the use efficiency (UE), fate, and loss of chemical fertilizer N in tomato field of Nanjing suburb. The results showed that the application of chemical fertilizer N did not show any benefit to the tomato yield, due to the adequate N supply from native soil and organic manure amendment. The UE of fertilizer N calculated by difference method ranged from 14.5% to 22.5%. In micro-plot experiment, 16.6%～28.8% of applied urea ¹⁵N was recovered by the plant, and 34.2%～46.0% of it was lost. Applying fertilizer N increased the nitrate content in 0～100 cm soil layer, and 10%～10.2% of urea ¹⁵N was leached to the depth below 40 cm at harvest time. N application increased the denitrification loss and N₂O emission significantly, which occupied 5.50%～6.01% and 2.62%～4.92% of the applied N, respectively. No ammonia volatilization was detected during the whole growth season. Reducing N application rate or applying coated urea could decrease the environmental risks of N application in vegetable fields, especially the risks from nitrate leaching and nitrification-denitrification loss.

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