黑龙港流域微地貌与地下水埋深对土壤潜在盐渍化的影响

目的]对近年河北省曲周县土壤潜在盐渍化进行多方位评价,为预防土壤盐渍化提供科学依据。方法]通过微咸水灌溉试验、土壤剖面观测和土样分析,从海拔高度、土层深度、地下水埋深、土壤质地几个方面对黑龙港流域土壤盐分运移以及其对土壤潜在盐渍化的影响进行探讨。结果]从区域角度分析,降雨和用微咸水灌溉加剧了表层盐分向下层淋洗的可能性,从而使土壤盐分多在40—100cm土层聚集。质地较为黏重的土层阻止了土壤盐分的运移而聚积在该土层之上,为土壤潜在盐渍化创造了条件。土壤盐分含量与海拔高度呈现出很好的相关性,其复相关指数R2=0.76。HCO_3~-的表聚现象比较明显,各土层土壤SO_4~(2-)离子和Ca~(2+)离子与全盐含量之间达到了显著和极显著相关(0.88*~1.00**,0.89*~0.97**),Ca~(2+)离子与SO_4~(2-)离子之间达到了显著和极显著相关(0.86*~0.97**)。结论]微地貌和土体构型的变化将会影响到土壤盐分的重新分配,进而对土壤潜在盐渍化有重要影响。

Effect of Micro-topography and Groundwater Depth on Soil Potential Salinization in Heilonggang Basin

Objective] To investigate the potential salinization of soil in Quzhou County, Hebei Province in recent years, in order to provide scientific basis for preventing soil salinization.Methods] The brackish water irrigation experiment, soil profile observation and soil sample analysis was conducted to study the soil salinity transport and its potential salinization to the soil in Heilonggang basin from the aspects of altitude, soil depth, groundwater depth and soil texture.Results] Rainfall and brackish water increased the possibility of surface salt leaching to the lower layer, which leads to the accumulation of soil salinity in 40-100 cm soil layer. Soil with more sticky texture appeared at 56 cm depth, which prevented the movement of soil salt and accumulated on it, thus creating potential conditions for soil salinization. Micro-topography affected the redistribution of salinity, and soil salinity content and altitude showed a good correlation (R²=0.76). The change of texture types in the soil layers at different depths affected the redistribution of soil salinity. The phenomenon of surface aggregation of HCO₃^- was obvious. The contents of SO₄^2- and Ca²⁺ in all soils were significantly correlated with total salt content (0.88^*~1.00^**, 0.89^*~0.97^**), and there was a significant relationship between the contents of SO₄^2- and Ca²⁺ (0.86^*~0.97^**).Conclusion] The change of micro-geomorphology and soil profile pattern will affect the redistribution of soil salinity, and have an important impact on the potential salinization of soil.