Nitrogen Leaching in Vegetable Fields in the Suburbs of Shanghai
Nitrogen Leaching in Vegetable Fields in the Suburbs of Shanghai
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发表时间：
2005
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通讯作者：
Cao;Lin-Kui;Chen;Guo-jun;Lu;Yi-Tong
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作者：
Cao;Lin-Kui;Chen;Guo-jun;Lu;Yi-Tong
2002年12月至2003年5月，在连续轮作的条件下，研究了全氮等量追施对菜田氮素淋失的影响。变种rosularis）和莴苣（Lactuca sativa L.）采用蒸渗仪法对上海市郊区某蔬菜生产基地的土壤氮素营养状况进行了调查，为合理利用氮肥，防止水资源氮素污染提供科学依据。结果表明，氮素淋失主要以硝态氮为主，占氮素淋失总量的90%以上，是造成地下水污染的重要原因。白菜田用等量的精制有机肥替代基肥中30%的化肥氮，硝态氮淋失量减少了64.5%;在大田中，用等量的精制有机肥替代1/2的基肥和1/3的追肥，硝态氮淋失量减少了46.6%。在大白菜和生菜连续两年轮作系统中，化肥施用量最高的处理硝态氮淋失量高达46.55 kg ha-1，而有机肥施用量最高的处理仅为17.58 kg ha-1。因此，在前两季用部分精制有机肥替代化学氮肥，对减少硝态氮淋失具有很大的优势。
Nitrogen (N) leaching in vegetable fields from December 2002 to May 2003 with equal dressings of total N for a sequential rotation of Chinese flat cabbage (Brassica chinensis L. var. rosularis) and lettuce (Lactuca sativa L.) in a suburban major vegetable production base of Shanghai were examined using the lysimeter method to provide a scientific basis for rational utilization of nitrogen fertilizers so as to prevent nitrogen pollution of water resources. Results showed that leached N consisted mainly of nitrate N, which accounted for up to more than 90% of the total N loss and could contribute to groundwater pollution. Data also showed that by partly substituting chemical N (30%) in a basal dressing with equivalent N of refined organic fertilizer in the Chinese fiat cabbage field, 64.5% of the leached nitrate N was reduced,while in the lettuce (Lactuca sativa L.) field, substituting 1/2 of the chemical N in a basal dressing and 1/3 of the chemical N in a top dressing with equivalent N of refined organic fertilizers reduced 46.6% of the leached nitrate N. In the two-year sequential rotation system of Chinese fiat cabbage and lettuce, nitrate-N leaching in the treatment with the highest amount of chemical fertilizer was up to 46.55 kg ha-1, while treatment plots with the highest amount of organic fertilizer had only 17.58 kg ha-1. Thus, partly substituting refined organic fertilizer for chemical nitrogen in the first two seasons has a great advantage of reducing nitrate-N leaching.