浅埋式滴灌土壤水分分布规律试验研究

以探寻合理的滴头埋深与流量为目的,开展浅埋式滴灌下土壤水分分布规律的试验研究。试验土箱净尺寸为30cm×30cm×60cm(长×宽×高),供试土壤取自新疆青河县阿苇灌区试验站。试验设置5、10、15 cm 3个滴头埋深,各埋深条件下设置不同流量的处理。结果表明:不同滴头埋深的情况下均存在土体破坏的临界流量,滴头埋深越大临界流量也越大,滴头埋深为5、10和15 cm对应的临界流量分别为1.0、1.7和2.5 L/h;随着流量的增大,滴头埋深过浅时,水量向湿润体上部聚集,当埋深超过一定深度时,水量向湿润体下部聚集;在临界流量情况下,湿润锋前60 min运移速率较快,随着滴头埋深的增大,灌水结束后湿润体的垂向湿润长度越长,土壤平均含水率值越小;滴头埋深为10 cm、流量1.7 L/h时,湿润体水分分布较为合理。

Laboratory experimental study on the soil moisture distribution of shallow subsurface drip irrigation

In this study, the distribution of soil moisture in shallow buried drip irrigation was investigated in order to find a reasonable buried depth and discharge of the drip. Tested soil was taken from Awei irrigation area, Qinghe, Xinjiang. The net size of the test soil box was 30cm × 30cm × 60cm (length × width × height). The drips were buried at 5, 10 and 15 cm, and different drip discharges were set at each depth. The results showed that there was a critical flow of soil damage under the condition of different drip depth, and the critical flow increased with the increase of the buried depth. The critical flow of the 5, 10 and 15 cm depths of the drip were 1.0, 1.7 and 2.5 L/h, respectively. When the dripper depth was too shallow, the amount of water gathered to the upper part of the wetting body. When the depth exceeded a certain depth, the water gathered to the lower part of the wetting body. In the case of critical flow, the migration rate of wet front was faster in the first 60 min. The deeper the drip buried, the longer the wetting length of the wetting body (after irrigation) was, the smaller the soil moisture content was. The wetting body moisture distribution was more reasonable when the drip depth was 10cm and drip discharge was 1.7 L/h.