贵州某地区农用地土壤镉含量特征与影响因素分析

Characteristics of analysis of influencing factors of Cd content in agricultural land in some place of Guizhou

为了解研究区镉(Cd)元素在农用地土壤中的含量特征、影响因素及对农作物的影响,让公众充分了解Cd污染土壤的原理,理性认识土壤与农作物中Cd含量的关系,强化土壤保护意识,同时为该区的土壤污染治理及合理调整种植结构提供科学依据。本文利用研究区1∶5万耕地质量地球化学调查海量样品测试数据开展了系统研究。研究结果表明,研究区农用地土壤中Cd含量整体属高背景值区,存在一定土壤污染风险;土壤中Cd元素主要来源于成土母岩风化,交通运输、一般工矿企业生产对其影响不大,但铝厂生产可能是农用地土壤Cd的另一来源;Cd高含量集中分布于成土母岩为二叠系及石炭系的土壤;农作物中辣椒和玉米存在一定的Cd污染安全风险,水稻和高梁受到Cd污染的安全风险较小;水稻、玉米、辣椒的Cd含量与其根系土Cd含量的相关性不大,高梁Cd含量与其根系土Cd含量有较强的正相关性。

To understand the distribution characteristics of cadmium(Cd)elements in agricultural soils in the study area,the influencing factors and the impact on crops,to let the public fully understand the root causes of Cd contaminated soils,to rationally understand the relationship between soil and Cd content in crops,to strengthen the awareness of soil protection,and at the same time to provide a scientific basis for soil pollution management and reasonable adjustment of planting structure in the area.A systematic study was conducted using the test data of 1∶50,000 arable land quality geochemical survey mass samples in the study area.The results show that the overall Cd content of agricultural soils in the study area is in the high background value area,and there is a certain risk of soil pollution;it mainly comes from the weathering of soil-forming parent rocks,transportation,general industrial and mining enterprises production has little effect,but aluminum plant production may be another source of Cd in agricultural soils;the high Cd content is concentrated in the strata of soil-forming parent rocks of Permian and Carboniferous;among agricultural crops,pepper and corn have a certain risk of the crops,pepper and maize have some safety risk of Cd contamination,while rice and sorghum have less safety risk of Cd contamination;the correlation between the Cd content of rice,maize and pepper and their rhizosphere soil Cd content is not significant,and the Cd content of sorghum has a strong positive correlation with its rhizosphere soil Cd content.