地膜中重金属对土壤-大豆系统污染的试验研究

Experimental Study of Pollution by Heavy Metals of Plastic Film in Soil-Soybean System

采用盆栽和田间试验方法,研究了大豆各生育时期,不同地膜残留量处理土壤和植株中Pb和Cd的含量。结果表明,大豆各生育时期,高倍地膜残留量土壤和植株中Pb和Cd含量高于低倍残留量;各生育时期各处理土壤中Pb含量为49～188mg/kg,差异达显著水平;Cd含量为0.7～2.4mg/kg。植株中Pb含量为0.022～0.097mg/kg,Cd含量为0.001～0.003mg/kg。与国家《土壤环境质量标准》GB15618—1995的Ⅱ级标准进行比较分析,土壤中Pb含量均未超标,Cd含量值均超标;与国家《食品中污染物限量》GB2762—2005标准比较分析,籽粒中Pb,Cd含量均未超过豆类食品限量标准,且Cd含量远远低于该标准。

Pot and filed experiments were conducted to study the Pb and Cd contents in soil and plants during soybean growth periods under the treatments of different residual amounts of mulching plastic film.Results showed that during soybean growth periods,the Pb and Cd contents in soil and the plants for high residual mulching film samples were higher than those for low.The Pb contents in soil were 49～188mg/kg;the Cd contents in soil,0.7～2.4mg/kg;the Pb contents in plants,0.022～0.097mg/kg;and the Cd contents in plants,0.001～0.0032mg/kg.By the secondary limit of China Environmental Quality Standards for Soils（GB15618—1995）,the Pd content in soil was less than the limit and the Cd content in soil was higher than the limit.By the China Maximum Levels of Contaminants in Foods（GB2762—2005）,the Pd and Cd contents in seeds were less than the level and the Cd content in seeds was much less than the level.