摘要
选取太湖东岸的青紫泥水稻土区,对常规施肥和不施肥条件下水稻季稻田氮、磷的流失进行了观测。结果表明:水稻种植季内田面水和降雨径流水中氮磷的浓度呈现前期高后期低的趋势,初期施肥之后的降雨流失使稻田水中氮磷浓度大幅度降低;整个水稻生长季稻田氮磷的流失总量分别达38.8和0.95kg.hm-2,且主要以田面水径流流失为主;氮素主要以水溶性的铵态氮流失,而磷素则主要为颗粒态流失。不施肥处理中稻田氮、磷流失分别是常规施肥处理的47%和60%;水稻生长初期降雨下的氮径流流失占整个水稻生长期的50%,磷素占33%。降雨事件下的流失是农田非点源污染的主要贡献期,因而应作为控制的关键因子;对于基础肥力高的水稻土可考虑轮流施肥以减少环境的氮、磷流失与水系污染风险。
A field observation on the nitrogen （N） and phosphorus （P） loss from a gley paddy soil （clayey illitic thermic typic Epiaqualf） in the Taihu Lake region during rice growth season showed that under conventional fertilization, the concentration of N and P in soil surface water and runoff was high at the early stage of rice growth, and then decreased quickly. The rainfall following fertilization caused a great decrease of N and P in soil surface water. During the whole growth season, the total runoff loss of N and P reached as high as 38. 8 kg N · hm^-2 and 0. 95 kg P· hm^-2, mainly through soil surface water. The majority of lost N was in NH4^＋ -N form, and that of lost P was particulate-P. Under no fertilization, the N and P loss was 47% and 60% of that under fertilization, respectively. At the early growth stage of rice, the runoff loss within 2 weeks after fertilization contributed about 50% of the total N loss and about 33% of the total P loss. The N and P loss after rain gave great contribution to the farmland non-point sources pollution. It was suggested that in the Taihu Lake region, fertilization by turns on the paddy soil with higher fertility could mitigate the N and P loss from paddy soil and the pollution risk of water system.
出处
《生态学杂志》
CAS
CSCD
北大核心
2007年第4期495-500,共6页
Chinese Journal of Ecology
基金
江苏省苏州市科技局项目
教育部骨干教师基金资助项目
关键词
施肥
水稻土
非点源污染
径流流失
fertilization
paddy soil
non-point sources pollution
runoff loss.
