间歇入渗对土壤溶质淋洗效率的影响

Impact of intermittent infiltration on solute leaching efficiency in soil

针对间歇入渗条件下土壤溶质运动规律研究的不足,采用室内土柱试验的方法,研究了相同灌水总量、不同灌水频次条件下的水分和溶质运动规律。试验结果表明:在无蒸发的条件下,间歇入渗会显著提高入渗和排水的速率,但不会影响到排水总量;在一定灌水频次范围内,间歇入渗会在不影响溶质淋洗效率的条件下提高溶质淋出的速率,但过多的灌水频次会导致土壤中水分运动速率过快,不能有效地携溶质向下层土壤迁移,导致溶质淋洗效率降低。该研究结果可为制定合理的间歇灌水制度提供一些依据和参考。

In view of insufficient reveal on flow and solute transport regimes under intermittent infiltration conditions, movement laws of water and solute were conducted under same total infiltration volume but different frequencies. Experimental results showed that without evaporation, intermittent infiltration significantly raised the average infiltration rate as well as drainage rate, but had no effect on the total drainage volume. With limited irrigation frequencies, it raised the solute leaching rate without influencing the final leaching efficiency. If the infiltration frequency was too high, the water flow velocity would be too fast to carried solute downwards, resulting in a decrease of the leaching efficiency. The results of this study provide a reference for intermittent irrigation schedule design.