滴灌条件下山区典型土壤水分运移规律分析

Analysis of Soil-water Movement Characteristics of Hill Area Soil Under the Condition of Drip Irrigation

在广西山区选择沙土、壤土和黏土等3种典型土壤,并开展滴灌在这3种土壤条件下的土壤水分运移规律研究。试验结果表明:1在地埋黏土、壤土和沙土以及0.10 MPa工作压力条件下,滴灌管的单米流量为4.17、5.92和6.10 L/h,为地表自由出流的67.58%、95.05%和98.87%;2滴灌在黏土的水分运移形状基本为圆形,在沙土和壤土的湿润形状为上小下大的椭圆形;3同等条件下,水分在沙土的水平和垂直向下运移速率最大,壤土次之,黏土最小;4在土箱相同位置,黏土的土壤含水率最大,壤土次之,沙土最小;5根据滴灌的土壤水分运移规律,提出滴灌管在广西山区沙土、壤土和黏土的适宜埋深分别为10、15和20 cm;6滴灌应用在山区条播作物时,在黏土、壤土、沙土的适宜滴孔间距应为35、30和25 cm。

Drip irrigation has already been applied in hill area of Guangxi. This experiment simulates the soil water movement characteristics of sandy soil, loam soil and clay soil under drip irrigation condition. The results show that： ①Under the condition of 0.10 MPa work pres- sure, the flow per meter of drip tube of buried clay, loam and sand, were 4.17, 5.92 and 6.10 L/h, respectively. ②The shape of water transport in clay was round, while that of water transport in sand and loam is ellipse. ③The migration velocity of soil-water in sandy soil is the highest, followed by that in loam soil and clay soil. ④ The soil-water content in the clay soil is the highest, followed by that in loam soil and in sandy soil. ⑤ Based on the results of this experiment, it is proposed that the capillary of sand, loam and clay in hill area reasonable depth should be 10 cm, 15 cm and 20 cm, respectively. ⑥The reasonable drop spacing should be 25 cm,30 cm and 35 em in sand, loam and clay soil, respectively.