土壤有机质含量对土壤水动力学参数的影响  

INFLUENCE OF ORGANIC MATTER CONTENT ON SOIL HYDRODYNAMIC PARAMETERS

作　　者：单秀枝[1] 魏由庆[1] 严慧峻[1] 刘继芳[1] 张锐[1] 

机构地区：[1]中国农业科学院土壤肥料研究所,北京100081

出　　处：《土壤学报》1998年第1期1-9,共9页Acta Pedologica Sinica

摘　　要：通过测定并分析不同有机质含量的壤质土样的饱和导水率、水分特征曲线、水分扩散率及几个水分常数，阐明了土壤有机质含量与水动力学参数的关系，从动力学角度探讨了有机质影响水分运动的机理。研究结果表明，随着有机质含量的增加，土壤饱和导水率呈抛物线变化，当有机质含量为15g／kg时，饱和导水率达到最大值。土壤中吸力相同时，有机质含量越高，土壤含水量越大，且滞后现象也越明显。土壤水分扩散率与土壤含水量呈指数函数关系。土壤含水量相同时，有机质含量越高，土壤水分扩散率越小。By testing and analysing saturated hydraulic conductivity in soil, water characteristic curve, water diffusion rate and water constant of loamy soils, with different levels of organic matter (O.M.), the relationship between hydrodynamic parameters and soil O. M. contents was explored in this work. The results are as follows:There was a linear relationship between saturated soil water contents (y1), field water-holding capacity (y2), or soil capillary water contents (y3) and soil O.M.content(x):The relationship between saturated hydraulic conductivity in soil (y) and soil O.M.content (x) was of parabolic: and when x equaled 15.0g / kg,y reached the highest point.The characteristic curve of soil water took a form of power function,S = a(θ /θs)b,when the suction force was in the range of 0-1500 kpa. But it took a form of exponential function, s = ae-θ＋b, when the suction force was in the range of 0－80kPa. S= aeθ＋b In case of the same suction, it appeared that the higher the O.M.content, the higher the water content in the soil and the more obvious the hysteresis phenomenon was. The relationship among the soil moisture suction (s), soil water content (θ), and soil O. M. content (x) was: s = 1693.4le(-o.26θ＋0.12x) in suction force of 80-1500kPa and s = 2.79θ＋1.28x ＋103.85 in 0－80kPa.The relationship between the soil water diffusion rate (D) and water content(θ)took the form of exponential fuction: D = aebθ. The higher the O. M. content, the lower the diffusion rate of soil water when water content was the same. The regression equation of the three factors had the form: D = 0.0036e(19.22θ-0.09x)

关 键 词：土壤有机质 土壤水动力学 参数 

分 类 号：S152.7[农业科学—土壤学] S153.621[农业科学—农业基础科学]