摘要
【目的】全面、系统地探究湟水流域耕地表层土壤有机碳的空间变异性和分布特征,解析其主要驱动因素,为提升耕地土壤质量、优化农田经营管理提供科学依据。【方法】以湟水流域为研究区域,借助经典统计分析、半变异函数、克里金插值、随机森林模型、偏最小二乘结构方程模型,分析流域内耕地表层土壤有机碳的空间分布及其驱动因素。【结果】研究区耕地表层土壤有机碳含量均值为13.68 g/kg,变异系数为32.98%;空间插值最优理论模型为高斯模型,块金系数为40.70%。土壤全氮、球囊霉素土壤相关蛋白、粉粒含量、土壤pH、根系干重、年均温和年均蒸发量对土壤有机碳含量有极显著影响(P<0.01),海拔和年均降水量达显著水平(P<0.05)。土壤性质对土壤有机碳的直接效应为0.76,地形因素主要通过影响气候和植被间接影响土壤性质,进而影响土壤有机碳,其间接效应为0.39。【结论】研究区耕地表层土壤有机碳含量的空间分布受土壤、地形、气候和植被等因素的综合影响,总体呈现出东南低、西北高的分布格局。土壤性质和地形因素分别是研究区耕地表层土壤有机碳空间变异最重要的直接和间接驱动因素,土壤全氮和总球囊霉素是其中最主要的直接驱动因子。
【Objective】The paper aimed to conduct a comprehensive and systematic investigation into the spatial variability and distribution characteristics of cultivated topsoil organic carbon in the Huangshui River Basin, analyze its main driving factors, and provide scientific evidence for improving soil quality and optimizing farmland management practices.【Method】Focusing on the Huangshui River Basin as the study area, the spatial distribution of cultivated topsoil organic carbon in farmland and its driving factors were analyzed using classical statistical analysis, semivariogram functions, kriging interpolation, random forest models and partial least squares path modeling.【Result】The average soil organic carbon content in the study area's plow layer was 13.68 g/kg, with a coefficient of variation of 32.98%.The optimal theoretical model for spatial interpolation was the Gaussian model, with a nugget coefficient of 40.70%.Total soil nitrogen, glomalin-related soil protein, silt content, soil pH,root dry weight, mean annual temperature and mean annual evaporation had highly significant effects on soil organic carbon content(P<0.01).Elevation and mean annual precipitation reached significant levels(P<0.05).The direct effect of soil properties on soil organic carbon was 0.76.Terrain factors mainly influenced soil properties indirectly by affecting climate and vegetation, thereby impacting soil organic carbon, with an indirect effect of 0.39.【Conclusion】The spatial distribution of cultivated topsoil organic carbon content in the study area is influenced by a combination of factors, including soil properties, topography, climate, and vegetation, generally showing a pattern of lower concentrations in the southeast and higher concentrations in the northwest.Soil properties and topographic factors are the most significant direct and indirect drivers of spatial variability in cultivated topsoil organic carbon, with total soil nitrogen and glomalin being the primary direct driving factors.
作者
林成清
李润杰
盛海彦
孔小云
辛继林
崔子龙
杨晓璇
党怡乐
马占明
万基中
张永坤
LIN Cheng-qing;LI Run-jie;SHENG Hai-yan;KONG Xiao-yun;XIN Ji-lin;CUI Zi-long;YANG Xiao-xuan;DANG Yi-le;MA Zhan-ming;WAN Ji-zhong;ZHANG Yong-kun(College of Agriculture and Animal Husbandry,Qinghai University,Xining 810016,China;State Key Laboratory of Plateau Ecology and Agriculture,Qinghai University,Xining 810016,China;College of Eco-Environmental Engineering,Qinghai University,Xining 810016,China;Institute of Mountain Hazards and Environment,Chinese Acadenuy of Sciences,Chengdu 610044,China)
出处
《西南农业学报》
北大核心
2025年第1期135-144,共10页
Southwest China Journal of Agricultural Sciences
基金
青海省科技厅项目(2024-SF-148)
国家自然基金青年项目(4220072854)
国家自然基金联合项目(U20A20115)。
关键词
湟水流域
土壤有机碳
空间分布
随机森林
结构方程
Huangshui River Basin
Soil organic carbon
Spatial distribution
Random forest
Structural equation
