化学调控剂对土壤和莴笋中Hg,Cd,Pb含量的影响研究

通过盆栽试验和解吸试验，研究了石灰，腐殖酸、硫化钠、亚硒酸钠等化学调控剂对土壤重金属Hg，CA，Pb含量及在植物体内积累的影响机理。研究表明：适用荆量的石灰、腐殖酸能显著抑制莴笋对Hg的吸收，增加土壤中Hg的含量；而Na2S则能显著抑制莴笋对Pb的吸收，增加土壤中Pb的含量。从农产品安全要求出发。在试验条件下。抑制土壤Hg、Cd、Pb进入莴笋体内的最佳化学物质及剂量分别为：石灰施用量为10．0g／kg、腐殖酸施用量为2．67g／kg，亚硒酸钠施用量为2．19mg／kg时，抑制Hg进入莴笋体内的效果最好；石灰施用量为10．0g／kg时抑制Cd进入莴笋体内的效果最好；石灰、腐殖酸，硫化钠施用量分别为10．0g／kg。2．67g／kg和0．47mg／kg时抑制Pb进入莴笋体内的效果最好。

Effects of Adjust Control Agent on Hg, Cd, Pb Content in Soil and Asparagus

Based on current situation of heavy metal contamination of vegetables in Chongqing, pot experiments were conducted to investigate the effects of certain chemical additives, such as limestone, humic acid, sodium sulfide and sodium selenite, on heavy metal uptake of asparagus lettuce and concerning mechanism in soil. Results showed that proper input of limestone and humie acid could significantly reduce mercury concentration in asparagus lettuce, whereas sodium sulfide could reduce lead uptaken by asparagus lettuce. According to the safety of agricultural products, the best chemical additives and their dosages which could reduce mercury, cadmium, and lead were obtained. Application of 10.0 g/kg of limestone, 2. 67 g/kg of humic acid sulfide and 2.19 mg/kg sodium selenite had the most effective results on reduction of mercury in asparagus lettuce, and input of 10.0 g/kg of limestone could most effectively decrease the cadmium concentration in asparagus lettuce. Meanwhile, 10. 0 g/kg of limestone, 2.67 g/kg of humic acid, and 0. 47 mg/kg of sodium sulfide could best reduce lead concentration in asparagus lettuce.