地下地膜截水墙——防止黄土梯田梯坎蒸发的抗旱增产技术

Underground Plastic Sheet WallAn Antidrought AgriculturalTechnique to Prevent Ground Evaporation on Loess Terrace Banks

梯坎蒸发引起的梯田“胁边”现象，严重影响梯田的作物产量。地下地膜截水墙技术可以有效阻断梯田土壤水分向梯坎方向的侧向运移，防止梯坎地面蒸发，抗旱保墒，消除“胁边”现象，大幅度提高梯田作物产量。１９９８年陕北米脂的试验表明，采用这一技术，梯田增产幅度可达５７．７％～８８．６％。

Plants are not growing near the bank as at the center on a terrace field in the loess plateau because of severe ground evaporation on the terrace banks. An underground plastic wall ,which is set up nearby the downslope bank and at the toe of the upslope bank, can interrupt lateral movement of soil moisture from the terrace field to the terrace bank, therefore , prevent ground evaporation on the banks. An experiment in a terrace field in Mizhi, Shaanxi province in 1998,show that the potato production in the trial plots with underground plastic sheet walls of 0.51.5 m in depth was 57.7%88.6% higher than the trial plot without the walls.