不同施肥方式下稻田氮磷流失特征

采用大田小区试验,研究3种不同施肥方式下稻田系统氮(N)、磷(P)流失特征。实验结果表明,施用尿素和缓释肥的混施处理(MT)田面水中总氮(TN)和总磷(TP)平均浓度均为最高,分别为24.01和3.78mg/L,降雨产生径流时的N、P流失风险最大。整个水稻季,MT处理的N、P径流流失负荷分别为23.91和2.67kg/hm2,均为3种施肥处理中最高;MT处理的N、P渗漏流失负荷也为最高,分别为9.19和1.79kg/hm2。相对于MT处理,施用尿素和BB肥的无机处理(CT)及施用有机肥的有机处理(OT)能分别减少14.69%和29.18%的N总流失负荷及61.85%和68.97%的P总流失负荷。N、P的径流流失是稻田N、P流失的主要途径。

Nitrogen and Phosphorus Loss in Paddy Field with Different Fertilizer Application

A field plot experiment was conducted to investigate nitrogen (N) and phosphorus (P) losses with different fertilizer treatments in rice field.The results indicated that the mixed treatments (MT),applied with urea and slow-release fertilizer,had the highest average concentration of total nitrogen (TN) and total phosphorus (TP) in surface water,which were 24.01 mg/L and 3.78 mg/L,respectively.For the rice season,MT caused the highest N and P loss,they were 23.91 and 1.79 kg/hm²,respectively.The leakage loss load of N and P treated with MT was 9.19 and 1.79 kg/hm²,respectively,which was also the highest in the three treatmentsCompared with MT treatment,the chemical treatments (CT) and organic treatments (OT) reduced N losses by 14.69% and 29.18%,P losses by 61.85% and 68.97%,respectively.The results demonstrated that the application of urea and organic manure has great potential effects on N and P loss reduction.Most of the N and P in paddy fields lost with surface runoff rather than subsurface leaching.