[目的]为明确侵蚀—沉积在黑土坡耕地土壤质量空间分异格局中的塑造作用。[方法]以东北典型水蚀区坡耕地为研究对象，利用110个样点的土壤属性，采用基于最小数据集的土壤质量指数(SQI)指标，评价坡面尺度土壤质量的空间分异特征，并利用广义线性模型(GLM)明确坡度、坡位、土层深度等因子对土壤质量的贡献。[结果](1)坡耕地土壤养分含量和空间特征在耕作层和亚表层间呈相反规律。对于大部分养分指标，耕作层的含量显著高于亚表层，但是，其空间异质性及土壤养分含量间的相关性低于亚表层(p＜0。05);(2)侵蚀沉积作用影响坡耕地土壤质量的空间分布特征。SQI在强烈侵蚀的坡中显著低于轻度侵蚀的坡上和沉积区的坡下(p＜0。05)，与坡上相比，坡中SQI在耕作层和亚表层分别降低26。2％和31。6％，沉积作用并不一定提高强烈侵蚀坡耕地沉积区的土壤质量，坡下和坡上耕作层的土壤质量无显著差异(p＞0。05);(3)土层深度、坡位和坡度是坡耕地SQI变异的主要影响因素。GLM结果显示，对于同一个土壤层次，坡度、坡位及其交互作用对SQI变异的解释度达95％，其中，坡位和坡度的解释度分别为68％和22％;考虑土壤深度因素，在0-40 cm 土层，土层深度、坡位和坡度对SQI变异的解释度分别为39％，31％和10％。[结论]采用SQI和GLM相结合的方法，明确侵蚀—沉积过程在坡耕地黑土质量空间分异中的塑造作用，研究成果可为典型水蚀区侵蚀退化黑土地质量评价和管理提供技术支撑。
Spatial Variation Characteristics and Influencing Factors of Black Soil Quality in Typical Water-Eroded Sloping Cropland
[Objective]This study aimed to clarity the role of sedimentation and erosion in shaping the spatial pattern of soil quality in black soil slope croplands.[Methods]Taking the sloping farmland in typical water-eroded areas in northeast China as the research object,we used the soil attributes of 110 sample points and the soil quality index(SQI)index based on the minimum data set to evaluate the spatial differentiation characteristics of soil quality at the slope scale,while the effects of slope gradient,slope position,and soil depth were determined using generalized linear models(GLMs).[Results](1)Opposing patterns of soil nutrient content and spatial characteristics were observed between the surface and subsurface layers in sloping croplands.Mostnutrient indicators exhibited significantly higher content in the tillage layer compared to the subsurface layer.However,the surface layer showed lower spatial heterogeneity and weaker correlation with related physicochemical indexes comparing with the subsurface layer(p＜0.05).(2)Erosion and sedimentation significantly influenced the spatial distribution characteristics of soil quality.The SQI was significantly lower in slopes with severe erosion compared to up-slope areas with weakly eroded regions and down-slope areas in depositional areas(p＜0.05).Compared with the upper position,the SQI of middle position was 26.2％and 31.6％lower at surface and subsurface soil layers,respectively.Sedimentation did not improve the soil quality of severely eroded slope croplands,and there were no significant differences in SQI between down-slope and up-slope areas(p＞0.05).(3)Soil depth,slope position,and slope gradient emerged as key factors influencing the variability of SQI in slope croplands.The GLM results demonstrated that,for the same soil horizon,slope,aspect,and their interactions explained over 95％variation in SQI.Among them,the explanatory degree of slope position was 68％,and that of slope gradient was 22％.Considering the factor of soil depth,the explanatory degrees of soil depth,slope position,and slope gradient on the variation of SQI in the range of 0-40 cm were 39％,31％,and 10％,respectively.[Conclusion]The combined method of SQI and GLM was used to clarify the shaping role of the erosion-sedimentation process in the spatial differentiation of black soil quality in sloping cropland,and the research results can provide technical support for the evaluation and management of the quality of eroded and degraded black soil in typical water-eroded areas.
soil erosionsedimentationtopographic factorssoil quality indexgeneralized linear model
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