山地丘陵交错地带耕层土壤pH和养分空间变异特征及影响因素分析

Spatial variability of cropland soil pH and nutrients and their affecting factors in mountainous hilly interlaced zone

【目的】研究山地丘陵交错地带耕层土壤pH和养分空间变异特征及影响因素,为指导山地丘陵交错地带开展农业生产和科学定量施肥提供参考依据。【方法】以湖北省广水市山地丘陵交错地带耕层土壤为研究对象,通过实地调查和室内检测获得200个土壤样点的相关数据,采用统计学、地统计学和GIS相结合的方法,分析土壤pH和有机质等土壤养分元素的空间分布特征及其影响因素。【结果】湖北省广水市山地丘陵交错地带耕层土壤pH和有机质、全氮、有效磷、速效钾、缓效钾含量变异程度均属中等变异,土壤养分元素均有弱空间相关性特征。养分含量在空间上以集聚分布为主,相互关系较弱,养分元素的块金效应值均处于25%~75%,养分元素的空间变异性受随机性因素和结构性因素共同影响。耕层土壤的pH介于5.5~6.5,以弱酸性土壤为主;有机质含量级别为适宜,有效磷、速效钾和缓效钾含量较高;全氮含量较低,含量级别为缺乏。有机质含量与生物多样性呈正相关,全氮含量与海拔和坡度呈负相关,速效钾含量与海拔呈负相关、与有效土层厚度呈正相关,缓效钾含量与有效土层厚度呈正相关,但相关性均较弱。【结论】湖北省广水市山地丘陵交错地带耕地表层土壤养分中除全氮含量较低外,其余养分元素的含量均不缺乏。土壤pH及主要养分元素的空间变异受自然因素和人为因素的共同作用。对于山地丘陵交错地带的耕层土壤养分含量而言,灌溉能力、海拔、坡向、坡度、有效土层厚度和生物多样性为主要影响因素。

【Objective】Study on spatial variability and influencing factors of soil nutrients in cropland soil in the interlaced zone of mountainous hills was conducted to provide theoretical basis for agricultural production and scientific quantitative fertilization in the interlaced zone of mountainous hills.【Method】Taking the cropland soil in the mountainous and hilly interlaced zone of Guangshui City,Hubei Province as the research object,based on the 200 soil samples date obtained from field surveys and laboratory tests,using the statistics,geostatistics and GIS methods,analysis of spatial distribution characteristics of nutrients such as pH and soil organic matter and their influencing factors was carried out.【Result】 The variability of soil pH,organic matter,total nitrogen,available phosphorus,available potassium and slowly available potassium in the cropland soil in the mountainous and hilly interlaced zone of Guangshui City,Hubei Province were all moderately variable,and soil nutrient elements were characterized by weak spatial correlation. The nutrient content was mainly concentrated in the space,and the relationship was weak. Nugget effect values of the nutrient elements were between 25% and 75%,the spatial heterogeneity of nutrient elements was formed by the combination of random factors and structural factors. The pH of cropland soil was between 5.5 and 6.5,which was mainly weakly acidic soil,the organic matter contents level was suitable. Content of available phosphorus,available potassium and slowly available potassium was high,the content of total nitrogen was low and content level was lack. There was a positive correlation between organic matter content and biodiversity,negative correlation between total nitrogen and altitude and slope,negative correlation between available potassium and altitude,and positive correlation between available potassium and effective soil thickness, positive correlation between slowly available potassium and effective soil thickness,but these correlations were weak. 【Conclusion】Except for the total nitrogen content is low,the content of other nutrient elements in not insufficient in cropland soil in the mountainous and hilly interlaced zone in Guangshui City,Hubei Province. The spatial variability of soil pH and major nutrient elements is affected by natural and human factors. For the soil nutrient content of cropland soil in the interlaced zone of mountainous hills,irrigation capacity,altitude,gradient,aspect,soil effective thickness,biodiversity are the main influencing factors.