不同灌水处理对多砾石砂土膜下滴灌玉米 水分分布特征的影响

为探究不同灌水定额对多砾石砂土膜下滴灌玉米土壤水分分布的影响,采用大田小区对比的试验方法,分析30.0mm、37.5mm、45.0mm、52.5mm、60.0mm五种灌水定额对土壤水分分布的影响。结果表明:同一灌水处理条件下,土壤剖面含水率等值线分布形式的变化过程是"长轴在垂向的椭圆形-长轴在横向的椭圆形-单峰曲线"。灌水24h后土壤含水率达到一个相对的稳定状态,且土壤表面25cm内的含水率明显小于灌后0h土壤含水率;40cm深度处土壤含水率达到最大。不同灌水定额土壤含水率变化趋势一致,随灌水定额的增加含水率等值线图越接近于椭圆形;在垂直方向与水平方向土壤含水率增加幅度分别表现为:中部下部上部、左部中部右部;52.5mm灌水定额处理下不同深度的土壤含水率最接近田间持水率。试验分析认为在多砾石砂土地区52.5mm灌水定额处理是水分分布最优的灌水处理。

Effect of different irrigation water treatments on water distribution characteristics of maize under submulched drip irrigation on pebbly sandy soil

In o r der to explor e t he effect o f different irrigat ion quo tas o n so il mo istur e distributio n o f m aize under drip irrig atio n on mulch pebbly sandy soil, the effect of 301 0 mm, 3 71 5 mm , 451 0 m m, 521 5 m m, and 601 0 m m irrigat ion quo tas on so il mo isture distributio n w ere analy zed by field plot com pariso n test m ethod. T he results show ed that the chang e pro cess o f t he co nto ur distributio n of so il w a ter content in the soil pro file w as the ellipse w ith t he long ax is in t he v ertical dir ect ion and t he ellipse w ith the long ax is in the horizontal dir ectio n2unimo da l cur ve. After 24 hours of irriga tio n, the so il mo istur e co nt ent reached a re lativ ely stable st ate, and the soil mo istur e co ntent w ith in 25 cm o f the so il surface w as sig nificantly low er t han that in 0 ho urs after irrigat ion. The so il mo istur e co nt ent w as the hig hest at a depth o f 40 cm. The chang ing t rend o f so il w ater co nt ent in differ ent irrig atio n quotas w as t he same, w hile the co nto ur map of soil w ater content w as closer to an ellipse w ith the incr ease o f irrig atio n quo ta. The increased rang e o f so il w ater co ntent in the v ert ical directio n and horizo nt al dir ec2 tion w as as fo llows: m iddle> low er> upper and left > m iddle> rig ht, r espectively. T he soil mo istur e co ntent at differ ent depths tr eated w ith a 521 5 mm irriga tio n quo ta w as closer to t he fie ld m oist ur e retentio n rate. T he ex perimental analysis show ed that 521 5 mm irrig atio n quot a tr eatment w as the best irrigat ion w ater tr eatment fo r w ater distributio n in the pebbly sa ndy soil ar ea.