膜袋灌入渗特性试验研究

Infiltration Characteristics under Film-bag Irrigation

通过二侧对称布置出水孔、孔径0．5mm、孔距30cm的膜袋灌试验，研究了不同灌水定额下膜袋灌湿润锋运移和湿润体内土壤水分的分布。结果表明，对于粉黏壤土，灌水结束24h时，450、525、600m3／hm2灌水定额下湿润锋水平方向最大运移距离分别为80．16、81．43、82．47cm．垂直方向运移最大距离分别为43．38、46．50、47．86cm；水平与垂直方向最大运移距离的比值分别为1．85、1．75、1．72；灌水结束72h后，膜袋灌溉土壤湿润程度的均匀性达到90％；大部分土壤相对含水率介于60％～85％之间。二侧对称布置出水孔、孔径0．5mm、孔距30cm的膜袋能够满足大田旱作物生长需水要求。

The spatial-temporal dynamic distributions of soil water and wetting front distance were studied under different irrigation quotas through the experiments under film-bag irrigation. Water holes were symmetrically arranged on both sides of film-bag with hole diameter of 0.5 mm and hole pitch of 30 cm. The results indicated that for powder clay loam, the largest horizontal wetting front migration distances were 80.16 cm, 81.43 cm, 82.47 cm, vertical migration the maximum distances were 43. 38 cm, 46.50 cm, 47.86 cm, and the ratios of the maximum horizontal distance to the largest vertical migration distance were 1.85,1. 75,1. 72 under irrigation quotas of 450 m3/hm2, 525 ma/hm2, 600 m3/hm2 after irrigation for 24 h. After irrigation for 72 h, irrigation uniformity reached 90% under film-bag irrigation. Most of relative soil water contents changed from 60% to 85%. This type of film-bag could meet water demand of dryland field crops.