中文摘要：

在大田滴灌条件下,开展了不同滴灌量和施肥水平下水、氮在土壤中的运移规律研究。结果表明：在大田滴灌条件下,地表沿滴头的土壤湿润锋呈圆形分布;在同一滴头流量下,随着灌水量的增加,水平湿润锋的迁移加快,湿润半径也相应增加;水平湿润锋随时间的变化呈显著的幂函数关系,湿润峰与入渗历时的拟合关系较好。滴灌结束后,在同一滴头流量下,随灌水量增加,土壤含水量随土层深度和径向距离的增大而递减,递减率随土层深度的增大而减小,湿润体内NH4^＋-N随水扩散的距离增大,并且在湿润区域内NH4^＋-N浓度得到提高,垂直方向NH4^＋-N的入渗距离也有所增大。随着灌水量的增大土壤湿润体NO3^--N的量增加,滴头附近NO3^--N的变化不太明显,而在湿润体边缘NO3^--N产生累积。

英文摘要：

The experiment was conducted to investigate the regulation of the soil-water moving in condition of different drop end flow and the irrigation volume between two soils with different bulk density.The results showed that：The wetting front became circular in the surface of soils.And the vertical wetting front was greater than horizontal as the same drop end flow and the irrigation volume.The horizontal radius and the vertical depth increased with continuous of water application.The wet speed of the horizontal direction and vertical were reduced sharply as certain minutes later.The horizontal infiltration rate become high with the soil bulk density increase,and the horizontal wetting front was remarkable power function with time.The speeds of horizontal wetting front become lower gradually in different bulk density soils,while the vertical front tend to high.As irrigation volume increased,moving distances in horizontal and in leakage depths in vertical of water increased,and the change distance in horizontal was more sharply.Moreover,NH4^＋-N and NO3^--N were influenced by drop end flows and irrigation volumes.The spread distance of NH4^＋-N was enlarged and its concentration in the wetting zone was enhanced with the increasing of the irrigation volume as well as the NH4^＋-N concentration in the horizontal direction.The increased of drop end flow influenced NH4^＋-N in the greatest spread distance.NO3^--N concentration in wetting soil was increased along with drop end flow and irrigation volume,minor concentration of NO3^--N was found in a radius of 16 cm around point source,while higher NO3^--N concentration at the boundary of the wetting volume.