半干旱灌溉地区采用地下排水控制土地盐化的效果评价

一项大规模地下排水研究项目RAJAD（拉贾斯坦邦农业排水研究项目），在印度的拉贾斯坦邦实施，旨在控制因灌溉引起的土壤盐碱化问题。在12个野外试验地点获得了大量的地下排水数据。田间结果表明，地下排水系统对控制土壤盐碱化具有积极意义。广泛的监测结果显示，地下排水系统是控制土壤盐碱化的有效途径。试验数据表明，有地下排水系统的所有地区，其土壤盐化度都呈现出逐渐下降的趋势。土壤的脱盐速度在排水间距较小（〈40m）时比排水间距较大时（〉40m）要快。雨季通过地下排水系统淋洗排出的盐分数量大于灌溉季节引入的盐分数量。

Subsurface drainage for salinity control in semi-arid irrigation region: performance assessment

A large-scale subsurface drainage research project, RAJAD (Rajasthan Agricultural Drainage Research Project), was implemented in Rajasthan, India to combat the soil salinity induced by irrigation operation. Large volume of field data on subsurface drainage (SSD) was collected from twelve test sites. Field data/information revealed that SSD has positive impacts on soil salinity control. Extensive monitoring showed that SSD was effective in salinity control.Extensive and detailed monitoring data showed that soil salinity had a downward trend in all soils with SSD installed. Salinity reclamation was faster in soils with narrower (<40 m) SSD spacings than the wider (>40 m) spacing. The salts leached through the SSD system during the monsoon season was larger than the salt input to the soil through irrigation.