【目的】探索黄河三角洲地区盐渍土在不同淋洗条件下土壤脱盐规律。【方法】通过室内土柱淋洗脱盐模拟试验,设置2种淋洗方式(连续淋洗和间歇淋洗),分析了在连续淋洗和间歇淋洗条件下土壤淋洗耗水量、淋洗滤液的矿化度随时间、滤液累积量的变化规律和滤液的脱盐速率,同时分析了0~20、20~40、40~60、60~80、80~100 cm土层的电导率、SAR(钠吸附比)的变化过程。【结果】①不同淋洗方式条件下,土体脱盐共有3个过程,分别为盐分峰值初步形成过程、盐分峰值向下移动过程和土柱底层土体盐分峰值消失过程;连续淋洗和间歇淋洗土柱为达到一般农作物(计划湿润层为0~60 cm)生长所需淋洗水量为472.70 mm和411.60 mm,间歇淋洗较连续淋洗省水14.8%。②连续淋洗和间歇淋洗滤液矿化度随时间均表现为幂函数关系;连续淋洗和间歇淋洗的滤液脱盐效率分别为18.45 g/L2和28.49 g/L2,连续淋洗的滤液脱盐效率为间歇淋洗的64.7%。③连续淋洗土柱和间歇淋洗土柱淋洗后含盐量是淋洗脱盐前的11.89%和8.39%(以40~60 cm土层为例),间歇淋洗土柱中各层pH值增量均小于在连续淋洗土柱中pH值的增量,并且在间歇淋洗后各层土壤pH值虽有增加,但是还在一般植物生长的允许范围内;间歇淋洗土柱中SAR减小量大于连续淋洗土柱中SAR的减小量,RSC增量小于连续淋洗土柱中RSC的增量,SAR和RSC均在一般植物生长的允许范围内。【结论】盐渍土经过淋洗脱盐可以达到植物生长的要求,同时,间歇淋洗明显比连续淋洗节约水,在生产实践中采用间歇淋洗土壤脱盐效果更好。

【Objective】The objective of this paper is to experimentally study the efficacy of different leaching methods in reclaiming the salt-affected soil in the Yellow River Delta.【Method】The experiments were conducted in columns packed with saline soil, and we compared two leaching methods: continuous leaching and intermittent leaching. In each treatment, we measured the water consumption of the leaching, the changes in salt content in the leachate, the accumulative leachate, as well as salt leaching rate. In the meantime, we also measured the electrical conductivity in soil at 0~20 cm, 20~40 cm, 40~60 cm, 60~80 cm and 80~100 cm depth.【Result】①There were three distinctive processes during the leaching process, including salt-peak formation process, downward movement of the dissolved salt and attenuation of the salt peak. Continuous leaching and intermittent leaching required472.70 mm and 411.60 mm of water respectively to make the 0~60 cm soil able for crops to grow. ②The change in salt concentration in the leachate under continuous and intermittent leaching with time followed a power-law during the experimental period, and the desalination efficiency of the continuous and intermittent leaching was18.45 g/L2 and 28.49 g/L2, respectively. ③ Taking 40~60 cm soil as an example, the leaching rate in it after continuous and intermittent leaching was 88.11% and 91.61% respectively. The increase in pH along the soil profile under intermittent leaching was less than that under continuous leaching. Although the soil pH in each soil layer increased slightly after intermittent leaching, it was within the tolerant range of plant growth. The decrease in SAR under intermittent leaching was less than that under continuous leaching, as supposed to RSC. However, both SAR and RSC were within the tolerant range for plant to grow.【Conclusion】Both continuous and intermittent leaching can desalinate the top soil to make it able for crops to grow, but the intermittent leaching was more water-efficient.