不同施肥处理对稻田氮素径流和渗漏损失的影响

Effects of Different Fertilization Treatments on Runoff and Leaching Losses of Nitrogen in Paddy Field

采用田间试验,研究了不施肥（CK）、常规施肥（CF）、90%常规施肥（90%CF）、80%常规施肥（80%CF）、控释复合肥（CRF）和有机—无机肥配施（MF）6种施肥处理对稻田氮素径流和渗漏损失的影响。结果表明：水稻田面水总氮（TN）和铵态氮（NH＋4—N）浓度在施肥后第2天达到峰值,之后快速下降,第7天后降至峰值的15%以下并趋于稳定,控制稻田氮素流失最关键的时间为施肥后1周。减量施肥可以有效降低田面水和渗漏水的氮素浓度。不同施肥处理（CK除外）TN径流损失量和氮素流失率分别为8.81~15.78kg/hm2和施N量的2.58%~4.96%,其中90%CF、80%CF、CRF和MF处理TN径流流失量分别较CF处理低22.05%,34.16%,44.17%和33.52%;TN渗漏损失量和氮素淋失率分别为18.86~40.39kg/hm2和施N量的3.55%~11.77%,其中90%CF、80%CF、CRF和MF处理的TN渗漏损失量分别较CF处理低24.57%,26.52%,53.29%和26.97%。减氮20%不仅能有效减少稻田氮素径流和渗漏损失,还能有效保障水稻产量,提高氮素利用率。

A field experiment was conducted to investigate the effects of six fertilization treatments,no fertilization（CK）,conventional fertilization（CF）,90%of CF（90%CF）,80%of CF（80%CF）,fertilization with slow release complex fertilizer（CRF）,and organic-inorganic fertilization（MF）,on runoff and leaching losses of nitrogen in paddy field.Major results were as follows：Application of fertilizers sharply increased the concentrations of total nitrogen（TN）and ammonium nitrogen（NH＋4-N）in surface water.The concentrations reached peak values in 2days and then rapidly decreased and stabilized at below 15% of the peak values in 7days after fertilization.It was the critical period to control runoff losses of nitrogen in one week after fertilization.Reducing fertilization could significantly reduce the concentration of nitrogen in surface and leaching water.Except for CK,the amount and rate of TN losses from different treatments through runoff were 8.81~15.78kg/hm2 and2.58%~4.96% of applied N,respectively.The losses of runoff TN from 90%CF,80%CF,CRF,and MF were 22.05%,34.16%,44.17%and 33.52%lower than that from CF.Similarly,the amount and rate of TN losses from different treatments through leaching were 18.86~40.39kg/hm2 and 3.55%~11.77% of applied N,respectively.The losses of beaching TN from 90%CF,80%CF,CRF,and MF were 24.57%,26.52%,53.29%,and 26.97%lower than that from CF.Reducing 20% of fertilizer N not only could reduce the runoff and leaching losses of TN,but also could ensure rice yield and improve utilization of nitrogen.