肥液浓度对单膜孔入渗NO_3^--N运移特性影响的室内试验研究

Laboratory experimental study on effects of fertilizer solution concentration on transport characteristics of NO_3^--N under single film hole infiltration

该文通过室内入渗试验,研究了不同浓度的单膜孔肥液入渗NO3--N的分布特性。研究表明:不同浓度的膜孔肥液入渗土壤NO3--N浓度的湿润锋运移距离与土壤水分运动的湿润锋一致;肥液浓度越大,相同入渗时间的NO3--N浓度锋运移距离越大,土壤剖面NO3--N浓度最大值越大,相同深度处土壤NO3--N浓度也越大。肥液入渗土壤NO3--N浓度分布特征与湿润体深度符合分段函数模型。供水入渗过程中,NO3--N浓度锋运移距离和浓度最大值均随时间的延长而增大;再分布过程中,NO3--N浓度锋运移距离继续增大,而NO3--N浓度最大值逐渐减小。

Based on indoor experiment, NO3^--N concentration distribution characteristics under single point source infiltration with different fertilizer solution concentrations were studied. The wetting front distance of NO3^--N concentration under film hole infiltration has the same pattern as the movement of soil wetting front. The concentration front distance of NO3^--N and the maximum value of NO3^--N concentration in soil profile increase with the increase of the solution concentration at the same time. The NO3^--N concentration increases with the increase of the solution concentration at the same depth. The NO3^--N concentration distribution characteristics and wetting frong depth under fertilizer solution infiltration satisfy the subsection function model. The concentration front distance of NO3^--N and the maximum value of NO3^--N concentration increase with the increase of the time in the process of water supply. The concentration front distance of NO3^--N increases with the increase of the time in the process of redistribution and the maximum value of NO3^--N concentration decreases.