河套平原典型县域耕地土壤养分空间变异特征研究

为研究河套平原地区土壤养分状况,探究县域尺度土壤养分的空间变异性与分布特征,以杭锦后旗县域耕地为对象,采用实地调查和地统计学相结合的方法,研究该区耕层土壤有机质、全氮、有效磷、速效钾养分含量状况,分析土壤养分空间分布及其变异特征。结果表明,研究区耕层土壤有机质、全氮、速效磷和速效钾平均含量依次为13.90 g/kg、0.93 g/kg、16.25 mg/kg和170.79 mg/kg,土壤有机质和全氮处于缺乏状态,速效磷含量中等,而速效钾的含量较为丰富。从空间变异及相关性看,各土壤养分的变异程度都为中等变异,有机质和速效钾为中等相关性,全氮和有效磷均为弱相关性。从空间分布格局看,土壤有机质与全氮分布规律相近,呈现西北部高、东南部和东北部低的特点;土壤速效钾整体分布较为均衡;速效磷空间差异明显,呈东高西低格局。针对该地区土壤养分含量及分布规律,在进行养分管理过程中,应以控氮、稳磷、稳钾、全区规划与重点应对相结合的原则,坚持以有机肥为主、有机与无机相结合的施肥策略。对县域尺度耕地土壤养分状况的调查研究和统计分析,明晰了区域土壤养分空间分布特征及其与土地利用方式之间的关系,为河套平原耕地土壤养分管理、地力培育以及合理施肥运筹等提供科学依据。

Spatial Variability of Soil Nutrients in Cultivated Land in Typical County of Hetao Plain

The paper aims to study the soil nutrient status in Hetao Plain and explore the spatial variability and distribution characteristics of soil nutrients at county scale. By taking the arable land in Hangjinhouqi County as the object, the content of soil organic matter, total soil nitrogen, available phosphorus and rapid available potassium in the cultivated soil were studied, the spatial variability and distribution characteristics of soil nutrients were analyzed by field investigation and geostatistics. The results showed that the average content of soil organic matter, total nitrogen, available phosphorus and available potassium in topsoil in the arable layer was 13.90 g/kg, 0.93 g/kg, 16.25 mg/kg and 170.79 mg/kg, respectively. The soil organic matter and total soil nitrogen in the arable layer were in a deficient state, the content of available phosphorus was moderate, and the rapid available potassium was abundant. From the perspective of spatial variation and correlation, the variation degree of soil nutrients was moderate, the organic matter and rapid available potassium were moderately correlated, and the total nitrogen and available phosphorus were weakly correlated. From the perspective of spatial distribution pattern, the soil organic matter came to a trend of high level in the northwest, low level in the southeast and northeast, and the distribution of soil total nitrogen was similar to that of soil organic matter. The overall distribution of available potassium in soil was relatively balanced; the spatial difference of available phosphorus was obvious, showing a pattern of east high and west low. Concerning the soil nutrient content and distribution in the region, the process of nutrient management should be as following: control the nitrogen, stabilize the phosphorus, stabilize the potassium, combine the planning of the whole district with the key response, and adhere to the organic fertilizer, organic and inorganic combined fertilization strategy. The investigation and statistical analysis of soil nutrient status at the county scale clarified the spatial distribution characteristics of regional soil nutrients and their relationship with land using patterns, providing a scientific basis for soil nutrient management, soil fertility and rational fertilization planning in Hetao Plain.