太原市农田土壤养分和重金属累积特征及相关性分析

Analysis on Characteristics and Correlation of Main Soil Nutrients and Heavy Metals Accumulation in Taiyuan

为了解太原市农田土壤养分和重金属累积状况,采用田间采样与室内分析相结合的方法,以太原市小店区、晋源区、清徐县、尖草坪区、阳曲县、古交县、娄烦县等7个农作物主产区为研究对象,研究土壤主要养分和重金属累积特征及相关性。结果表明,小店区、晋源区和清徐县3个区县土壤养分和重金属含量相对较高;土壤中重金属Hg,Pb和土壤有机质(SOM)、全氮(TN)存在极显著正相关性,其主要来源于有机物料的施入;重金属元素Ni,Cu,Cr,As,Zn和土壤全钾(TK)存在极显著正相关,其主要来源于成土母质;土壤中有效磷(AP)、速效钾(AK)和碱解氮(AN)主要来源于化学类肥料;通过土壤有机质(SOM)和重金属Hg,Pb含量间的关系建立数学模型,预测土壤有机质的环境安全阈值为50.35g/kg。

To understand the accumulation of soil nutrients and heavy metals in the farmland of Taiyuan city,the study was conducted by using combination of field sampling and indoor analysis in 7 counties,including Xiaodian,Qingxu,Jinyuan,Jiancaoping,Yangqu,Gujiao,Loufan,which were the main crop production areas of Taiyuan.The accumulation characteristics and correlation of main nutrients and heavy metals in soil were studied.The results showed that the content of soil nutrients and heavy metals was relatively high in Xindian,Jinyuan and Qingxu.There was a very significant positive correlation between heavy metals Hg,Pb,and soil organic matter and total nitrogen in soil,mainly due to the introduction of organic materials.Heavy metal elements Ni,Cu,Cr,As,Zn and soil total potassium(TK) had a very significant positive correlation,mainly from parent soil.The effective phosphorus(AP),available potassium(AK),and alkalescent nitrogen(AN) in the soil were mainly derived from chemical fertilizers.A mathematical model was established through the relationship between soil organic matter and the content of heavy metals Hg and Pb,and the environmental safety threshold for soil organic matter was predicted to be 50.35 g/kg.