夏尔希里地区表层土壤养分空间异质性研究

Spatial Heterogeneity of Surface Soil Nutrients in the Xiaerxili Area

以夏尔希里地区为研究区,运用统计学和地统计学相结合的方法,研究土壤表层(0~10cm)的有机质(OM)、有效磷(AP)、速效钾(AK)养分含量以及空间变异特征。结果表明:研究区土壤表层OM、AP、AK含量分别为(3.267±2.25)%、(6.751±4.85)mg/kg、(25.82±14.72)mg/kg,OM、AP、AK含量均为中等变异;研究区土壤OM、AK最佳拟合模型为球状模型,AP最佳拟合模型为指数模型,决定系数均很高(0.738~0.994);OM、AP为空间强烈自相关,AK为中等空间自相关。OM、AP变程较长(7905.52、5346.75m),空间上连续性较好。AK变程较短(4325.64m),空间依赖性较强。土壤OM含量空间分布呈现山地森林区>绿洲区>荒漠区的特征,AP、AK含量空间分布均呈现绿洲区>山地森林区>荒漠区的特征;山地森林区表层土壤空间异质性主要受坡度、海拔高度、坡面曲率的影响。夏尔希里地区表层土壤养分存在不同空间异质性和空间关联性,这为干旱区土壤养分管理、可持续利用策略以及生态恢复提供了理论依据。

Taking the Xiaerxili area as the research area,the contents of organic matter (OM),AP and AK nutrients and spatial variation characteristics of soil surface layer (0-10 cm) were studied by combining statistics and geostatistics.The results showed that the content of organic matter (OM),effective phosphorus (AP),available potassium (AK) in the study area respectively (3.267±2.25)%,(6.751±4.85) mg/kg,( 25.82±14.72) mg/kg,OM,AP and AK content were the medium variation;the optimal fitting model of soil OM and AK in the study area was spherical model,while the optimal fitting model of AP was exponential model,with high determination coefficient (0.738~0.994).OM and AP spaces were strongly autocorrelation,and AK was medium spatial autocorrelation.OM and AP had a long variable range ( 7 905.52 ,5 346.75 m),with good spatial continuity.AK variable range was short (4 325.64 m),with strong spatial dependence.The spatial distribution of soil OM content was characterized by mountain forest area > oasis area > desert area,and the spatial distribution of AP and AK content were characterized by oasis area > mountain forest area > desert area;the spatial heterogeneity of surface soil in mountain forest was mainly affected by slope,altitude and slope curvature.There were different spatial heterogeneity and spatial correlation between surface soil nutrients in Xiaerxili area,which provide theoretical basis for soil nutrient management,sustainable utilization strategy and ecological restoration in arid area.