不同施肥处理对稻田系统氮素流失的影响

Studies on the Nitrogen Loss from Rice Field with Different Fertilizer Treatments

通过测坑定位试验,研究了3种施肥处理下稻田系统氮素流失特征。试验结果表明,施肥后各个处理的稻田坑面水中NH4+-N浓度逐日递减,无机肥处理,混施肥处理和有机肥处理的NH4+-N浓度在施肥第2天分别降低35.17%、24.78%、14.12%;施用有机肥能有效降低氮素在稻田土层中的淋溶速率,低于无机肥处理和混施肥处理,施肥第7天50 cm剖面水的总氮浓度,无机肥处理、混施肥处理和有机肥处理分别下降了53.0%、52.6%、44.2%。有机肥处理的渗漏水NO3--N含量最低,分别是无机肥处理和混施肥处理的47.8%和65.8%。施用有机肥能降低径流水和渗漏水的总氮流失,分别比无机肥处理减少39.70%和62.07%,但对水稻产量没有显著影响。

Based on the lysimeter method, the nitrogen loss in different fertilizer treatments were studied in the rice field. The resuhs showed that the concentrations of nitrogen in the rice field water decreased day by day after fertilization in each treatment. On the next day after fertilization, the concentrations of NH3-N in the surface water in the chemical fertilizer treatment, mixed fertilizer treatment and organic fertilizer treatment decreased by 35.17% ,24.78% and 14.12% ,respectively. Application of organic fertilizer can effectively reduce the rate of nitrogen leaching in the soil. The TN concentrations of leaching water in 50 cm depth in the chemical fertilizer treatment, mixed fertilizer treatment and organic fertilizer treatment reduced respectively by 53.0% ,52.6% ,44.2% on the seventh day after fertilization. The concentration of NO3-N in the leaking water in the organic fertilizer treatment was lowerest,which was respectively 47.8% and 65.8% of the chemical fertilizer treatment and mixed fertilizer treatment. Application of organic fertilizer can reduce the nitrogen loss in the runoff water and seeping water,which reduced by 39.70% and 62.07% than the chemical fertilizer treatment without causing a dramatic reduction in the rice yield.