渭河干流沿岸土壤有机质空间分布特征及其影响因素

通过野外实地调查,系统采集了渭河干流区域土壤表层及深层样品,利用方差分析、缓冲区分析等分析方法,研究了土地利用类型、海拔、坡度、坡向以及距离河岸的距离因素对土壤有机质空间分布的影响。结果表明,渭河流域沿岸区域土壤有机质含量总体偏低,分布不均,变异性较大,随着土层深度增加有机质含量逐渐降低。土地利用类型、海拔、坡度、坡向以及距离河流的距离因素只在20 cm以上土层具有显著影响。不同用地类型有机质含量的顺序是:农田> 林地> 果园> 荒滩草地。随着海拔升高,有机质含量逐渐增加。阴坡和半阴坡的有机质含量明显高于阳坡。离河岸越远有机质含量越高,随深度增加这种趋势逐渐减弱。

Spatial Distribution Characteristics of Soil Organic Matter and Its Influencing Factors on Two Sides Along Mainstream of Weihe River

Through field survey, systematic soil sample collection from surface soils and deep soil layers in the area, effects of land use type, altitude, slope degree and slope aspect on spatial distribution of soil organic matter are studied using variance analysis and buffer analysis methods. Results show that soil organic matter content on the two side areas is low overall, with an uneven distribution and large variability, and gradually declines with decreasing soil depth. Land use type, altitude, slope degree, slope aspect and the distance to the river have significant effects on soil organic matter only within 20 cm of soil surface. Land types, in order of decreasing organic matter content, are farmland, woodland, grassland and orchard wasteland. Organic matter content increases gradually with increasing altitude. Organic matter content on shady and semi-shady slopes is higher than that on sunny slope. Organic matter content increases away from the river bank, but gradually declines with increasing soil depth.