用大型Lysimeter和TDR测算赣东北红壤农田的渗漏量

Estimating Water Leakage in Red Soil Farmland Using Lysimeter and TDR in Northeast Jiangxi Province

红壤农田的渗漏量及透水性能对评价红壤水土流失状况具有很重要的意义。利用大型称重式蒸渗仪、时域反射仪和张力计 ,研究了赣东北红壤农田的渗漏量。结果表明 ,红壤农田土体渗漏性能良好 ,4 0 0 cm处最高日渗漏量可达 6 0 mm / d;3年结果表明年渗漏量为 10 36 .37～ 16 2 0 .4 6 mm,占到年降水量的 5 5 .1%～ 6 7.0 % ;在有花生生长和等高种植的情况下 ,即使在雨季 ,缓坡农田的径流量也很小而渗漏量较大。红壤表层以下的透水状况不是造成土壤侵蚀的主要因素。红壤坡荒地开垦为农田后 。

The soil water leakage and permeability are useful to evaluate the status of water and soil loss in red soil farmland. The water leakages in red soil farmland in northeast of Jiangxi province were studied using large scale weighing lysimeter, time domain reflectometry and tensiometer. The results showed that water permeability in red soil farmland was very good, with a largest daily leakage of 60 mm/d in the layer of 400 cm. Three years results showed an annual leakage ranged from 1 036.37 mm to 1 620.46 mm, accounting for 55.1% ～67.0% of the annual precipitation. With the peanut planting in contour, the runoff in the slow slope farmland was slight even in the rainy season, while the leakage was very large.The water permeability below the red soil surface layer is not the main factor that induces soil erosion. Once the slope badlands were cultured as farmland, the infiltration capability in the soil surface could be increased and the water and soil loss could be reduced.