天津市滨海盐碱地刺槐种植区水盐动态变化规律

目的]通过对滨海地区盐碱土水盐动态变化规律的研究,为该地区的土壤利用以及植树造林提供科学依据。方法]以天津大港地区刺槐林土壤为研究对象,研究不同土层的土壤水盐年份变化和盐分离子分布特征。结果]试验地土壤全年含水量变化范围在11.9%~28.8%;含盐量变化范围在4.2%~18.4%。春(3—5月)秋(9—11月)季节土壤含水量低,含盐量高,土壤盐分含量随土层深度增加逐渐降低;夏季(6—8月),土壤含水量高,含盐量低,土壤盐分含量随土层深度的增加逐渐升高。pH值在7.37~8.39之间,土壤中K+,Na+,Ca2+,Mg2+和Cl-春季表层土壤(0—10cm)含量最高,分别为0.04,4.27,2.69,1.04和10.03g/kg。除SO2-4和HCO-3外,其他盐分离子在春季变异系数(29.99~162.98)明显大于夏秋季节(2.87~88.13)。结论]不同土层的土壤含水量和含盐量随当地降雨量呈明显的季节性变化;试验地区土壤属于碱性土壤,随季节变化不明显;K+,Na+,Ca2+,Mg2+和Cl-与含盐量变化趋势保持一致,SO2-4和HCO-3随季节变化没有明显的规律性;春季各盐分离子在土壤中分布极为不均。

Soil Water and Salt Dynamic Variation in Robinia Pseudoacacia Planting Area of Coastal Saline-Alkali Area in Tianjin City

Objective] The purpose of this study is to investigate the dynamic variation of soil water and salt in coastal saline-alkali area in Tianjin, and provide scientific basis for soil utilization and forest planting.Methods] We took the Robinia pseudoacacia soil in Dagang district of Tianjin City as a case study, to study the annual variation of soil water and salt and salt ions distribution characteristics in different soil layers.Results] The annual soil water content varied from 11.9%~28.8%, while salt content varied from 4.2%~18.4%. In spring(March to May) and autumn(September to November), soil water content was the lowest while salt content was the highest. Soil salt content increased with the increase of soil depth. Soil pH value ranged from 7.37 to 8.39. The content of K⁺, Na⁺, Ca²⁺, Mg²⁺ and Cl^- was the highest in the top layer(0-10 cm) in spring, and it was 0.04, 4.27, 2.69, 1.04 and 10.03 g/kg, respectively. Except for SO₄^2- and HCO₃^-, the coefficient variation of salt ions(29.99~162.98) in spring was greater than that in summer(2.87~88.13).Conclusion] Soil water and salt content in different soil layers show an obvious seasonal variation along with local rainfall. Soil in the study area belongs to alkaline soil, and there is no significant seasonal change in soil pH value. Variations in K⁺, Na⁺, Ca²⁺, Mg²⁺ and Cl^- are consistent with soil salt content, while there is no significant seasonal variation in SO₄^2- and HCO₃^-. The distribution of salt ions is extremely uneven in spring.