县域尺度农田生态系统土壤养分特征研究

以山西省襄汾县为研究区域,采集100个农田耕作层表土,用相关分析和主成分分析的方法,研究了县域尺度小麦—玉米轮作下,耕作层土壤有机质、全氮、速效磷、速效钾含量及铁、锰、铜、锌、硼和硫这6种中、微量元素含量的变化特征。结果表明,土壤有机质与全氮、锰、硫的含量呈极显著正相关,与速效磷和锌的含量呈显著正相关;由主成分分析可知,土壤有机质、速效磷和全铜含量密切相关;全县耕作层土壤有机质均值为11.41 g/kg,全氮含量为1.01 g/kg,属中等偏上水平;速效钾含量为201.75 mg/kg,水平较高;而铁、锰、铜、锌、硼和硫的平均含量分别为4.55,6.74,1.14,1.33,0.69,71.07 mg/kg,水平偏低,说明耕作层普遍缺乏中、微量元素。

Soil Nutrient Properties of Agro-ecosystem on a County Scale

Taking Xiangfen in Shanxi as the research case,100 soil samples were collected under winter wheat/summer maize rotate cropping to study the changing trend of topsoil organic matter,total nitrogen,available phosphorus,available potass and iron,manganese,copper,zinc,boron and sulfur six medium,microelements content on a county scale by correlation and principle components.The correlation between soil organic matter and total nitrogen,Mn and S elements was significantly positive.The relationship between soil organic matter and available phosphorus and Cu content was significant by principle components analyzed.The mean value of topsoil soil organic matter and total nitrogen,available potassium were 11.41 g/kg,1.01 g/kg and 201.75 mg/kg respectively at higher level.The mean value of Fe,Mn,Cu,Zn,B,S were 4.55,6.74,1.14,1.33,0.69,71.07 mg/kg,respectively at lower level.The county scale topsoil generally lack medium and micro elements.