南京郊区大白菜生长期氮素的供应及利用  

N Supply and N Recovery by Chinese Cabbage During the Growing Period in Nanjing Suburbs

作　　者：贺发云[1] 尹斌[1] 曹兵[2] 蔡贵信[1] 

机构地区：[1]土壤与农业可持续发展国家重点实验室(中国科学院南京土壤研究所),南京210008 [2]北京市农林科学院植物营养与资源研究所,北京100089

出　　处：《土壤》2006年第6期692-697,共6页Soils

基　　金：国家自然科学基金项目(40171048)资助。

摘　　要：在南京郊区露地生产条件下，研究了不同施肥处理秋季大白菜生长期的土壤N素供应、作物养分吸收利用和肥料N素损失。结果表明，在大白菜整个生育期，耕层土壤供N量为50．7kg／hm^2，占土壤全N量的1．07％。作物收获期地上部分生物量和N素含量随施N量的提高而升高，施用N肥显著增加了大白菜的生物量，提高幅度高达3—4倍。植株吸收N量70％以上来源于肥料N。在水试验条件下，尿素N肥表观利用率为26％-35％，土壤NO3^--N含量随N肥施用量的增加而升高，主要累积在0—40cm土层中。A field experiment was conducted on Chinese cabbage in Nanjing suburbs to investigate soil nitrogen supply, nutrient uptake by the vegetable and chemical N losses during its growing period. Results showed that the amount of N supplied to the crop by the soil in the 0 - 20 cm layer was 50.7 kg/hm^2, accounting for 1.07% of the total soil N in the layer. Application of N fertilizer significantly increased yield of Chinese cabbage by 3 ~ 4 times. More than 70% of the N taken up by Chinese cabbage was derived from chemical N fertilizer. In the field experiment, the apparent recovery rate of urea was 26% - 35%. Nitrate content in the 0 - 40 cm soil profile increased with N application rate.

关 键 词：大白菜 土壤供氮量 氮肥利用率 

分 类 号：S143.1[农业科学—肥料学]