华南湿润区坡地氮素流失规律比较试验研究

A comparative experiment of nitrogen loss from the humid hillside areas of the south China

通过两个径流场的对比试验,研究了华南湿润地区针叶林坡面氮素随降雨径流的流失规律,结果表明,氮素流失量均与坡面径流量和降雨强度具有极显著的线性相关关系,在没有施肥的情况下,氮流失形态以氨氮、硝氮为主,总氮产出浓度随降雨径流的增大,逐步下降,最后趋于稳定。在施放尿素的情况下,氮素随径流的流失形态以氨氮、硝氮和溶解态的尿素为主,总氮的产出浓度呈先升高而后随降雨径流的增大逐渐减少最后趋于稳定的特性。

Thorough analysis is conducted on the relations between the loss of the nitrogen and precipitation changes in the hillside areas characterized by humid climate,the south China,based on experimental practices.The results indicate significant linear regressive relations between the loss of nitrogen,precipitation intensify and runoff variations.Without fertilization,the loss of the nitrogen is dominated by the loss of ammonia nitrogen and nitrate nitrogen,and the loss of the total nitrogen is decreasing when the precipitation intensity is increasing and then the loss of the total nitrogen is in moderate changes without evident decrease.With fertilization of carbamide,the loss of the nitrogen is dominated by the loss of the ammonia nitrogen,the nitrate nitrogen and the carbamide in the liquid state.The loss of the total nitrogen is increasing and then is decreasing when the precipitation intensity is increasing.Then the loss of the nitrogen is in moderate changes without evident decrease of increase.