不同水氮供施模式下红枣滴灌土壤水盐氮分布规律

Research on Distributions of Water,Salt and Nitrogen Content by Different Water and Nitrogen Supply Model for Red Jujube Drip Irrigation

对不同水氮供施下的土壤水、盐、氮在土壤中的分布规律进行研究,探索红枣滴灌条件下水肥盐的合理调控模式。根据滴灌灌水(W)和施尿素(N)的先后顺序,设置4种不同水氮供施模式。T1为水氮同步供施;T2为前T/4供水,中T/4～3T/4水肥同步,后T/4供水;T3为前T/2供水,后T/2水肥同步;T4为前T/2供水,中2T/4～3T/4水肥同步,后T/4供水。结果表明,各处理土壤含水率分布基本一致;各处理土壤盐分在滴头附近洗盐,湿润体边缘积盐,但T2和T4处理在滴头附近对土壤盐分的淋洗效果优于其他两种处理;土壤剖面NO3--N除T1处理外,各处理在湿润体边缘和土壤表层出现积累,积累程度为T2>T3>T4,垂直方向NO3--N为T4>T3>T2。结合土壤盐分和NO3--N的分布,T4是比较好的水氮供施模式,具有良好的控盐调肥效果。

Research on regularities of distribution for water,salt and Nitrogen content by different water and Nitrogen supply modes was conducted to explore rational regulation model about soil water,salt and fertilization under the condition of drip irrigation.According to the application order of nitrogen fertilizer（N） solution and water（W） involved in an irrigation time（T）,four fertigation treatments were designed,nitrogen applied throughout the irrigation cycle（T1）,in the middle of T/4-3T/4（T2）,at the end of T/2（T3） and in the middle of 2T/4-3T/4（T4）,respectively.The results showed that soil water content distribute the same among the treatments;In all treatments,soil salt was leached around the emitter area,but accumulated along the boundary of the moist volume.in which,T2 and T4 treatment showed better soil salt leached effects than the other treatments.Soil NO3——N accumulated mainly outside the moist volume and soil surface except T1,accumulation degree were T2T3T4,vertical accumulation degree were T4T3T2.The results suggested that the T4 treatment,nitrogen applied in the middle T/4,would rational for salt control and nitrogen fertilize regulation.