【作者】 杜连凤； 张维理； 赵同科；

【Author】 DU Lian-feng 1,2 ,ZHANG Wei-li 1 ,ZHAO Tong-ke 2 (1. Institute of Agriculture Resources and Regional Planning,Chinese academy of agriculture science ,Beijing 100081,China; 2. Institute of Plant Nutrition and Resources,Beijing Academy of Agricultural and Forestry Sciences,Beijing 100097,China)

【机构】 中国农业科学院农业资源与农业区划研究所； 北京市农林科学院植物营养与资源研究所；

【摘要】 采用15N示踪法和差减法结合,对浙江嘉兴市3种氮素水平菜田-菜稻轮作田、低龄保护地(3年)和高龄保护地(10年)的氮肥利用、损失等进行了研究。结果表明,不施肥处理随着土壤氮素水平的增加油菜生物量呈增加趋势。但干重先增加后降低,油菜含氮量随土壤氮素含量的增加和氮肥的施用量呈增加趋势。根据差减法计算的氮肥利用率随土壤氮素含量的增加呈明显降低趋势,相反损失呈明显增加趋势。差减法氮肥利用率为2.3%～14.3%,损失率为23.9%～71.8%。示踪法利用率呈先增加后降低趋势,为14.6%～29.4%。示踪法损失率随土壤氮素水平的提高呈明显增加趋势,为34.5～61.0。示踪法和差减法总体趋势一致。更多还原

【Abstract】 The fates of nitrogen(N) fertilizer (urea) in three types of vegetable fields with different fertility (mainly nitrogen) levels,including low N level (vegetable and rice rotation field),middle N level (new protected vegetable cultivation field),and high N level (old protected vegetable cultivation field) were studied with the methods of 15 N isotope technique together with different calculation methods in Jiaxing city,Zhejiang province. The results showed that cole fresh yield was increased with soil nitrogen (N) level of three fields with no N application,but the dry yield was increased first and then decreased. The N contents of cole were all increased with soil N level and fertilization. N use efficiency (NUE) calculated by different methods presented downtrend with soil N level,ranging from 2.3% to 14.3%. However,the N loss rates (NLR) increased with soil N level. Tracer method and subtration method gave similar NUE and NLR.更多还原