灌溉不同水质条件下滨海盐土脱盐动态的研究

The Desalting Dynamic State of Coastal Solonchak Soil Under Irrigation with Different Quality Water

通过在天津滨海新区的野外灌水脱盐试验,对比分析了灌溉淡水、中水和微咸水的中壤质、粘土和贝壳堤土土壤含盐量及pH的动态变化。结果表明,粘质滨海盐土经灌淡水后的土壤全盐量降低是逐渐的,中壤质滨海盐土则第一次灌水后土壤含盐量降低较多,表层(0～20cm)由1.75%降到0.511%,以后灌溉土壤全盐量降低得较缓慢,20～40cm土层的含盐量始终降低得较缓慢。灌溉淡水、中水、微咸水均能使土壤全盐量降低,灌溉中水、微咸水后表层和土体下层土壤的含盐量均逐渐降低,而灌溉淡水的土壤表层全盐量降低明显,土体下层的土壤全盐量变化幅度较小。灌溉淡水、中水、微咸水均使土壤pH有升高的趋势,灌溉淡水后表层土壤pH能够上升到9.0,灌溉微咸水、中水后土壤pH能够升至8.5左右。

The field experiments of irrigation with the fresh water, recycled water, saltish water to take off salt from soil were carried out in Tianjin sea shore new developed area, Contrasted and analyzed the dynamic state variety of the soil salinity and the pH after irrigating fresh water, recycled water and saltish water in clay soil, heavy loamy soil, and medium loamy soil. The results showed that the soil salinity of the coastal salt clay soil lowers gradually after irrigating the fresh water,while the salt content of the medium loamy soil reduces more rapidly after the first time irrigating with the fresh water. The salt content in surface layer （0-20 cm ） was declined to 0.5 11% by 1.75%, then after the salt content of soil lowers rather slowly with additional irrigation. The salt content in 20-40 cm soil layer was declined slowly all the time .Irrigating the fresh water, recycled water, sahish water all can make the soil salt content lower. The soil salt content of both surface layer and lower layers of the soil body was declined gradually all the time on the condition of irrigating both recycled water and sahish water. While irrigating fresh water, the soil salt content of surface layer reduces more obviously, but the variety range of soil salt content in other layers of the soil body ismuch smaller. Irrigating the fresh water, the recycled water, the saltish water all can make the trend that the soil pH gone up. Soil pH of the surface layer soil could achieve 9.0 after irrigating the fresh water, pH of the surface layer soil could go up to 8.5 or so after irrigating the saltish water or the recycled water.