The Effects Of Several Amendments On Forms Of Lead And Its Uptake By Two Cultivars Of Brassica Chinensis In An Acid Red Soil

Heavy metal pollution in soils" is a major environmental concern in the world and particularly in China as a result of the rapid industrization.Lead(Pb) is a ubiquitous element in soil environments due to natural and anthropogenic pathways;it is highly toxic to plants,wildlife and humans. Vegetable plantation soils contaminated by Pb would pose long-term healthrisks to animals and humans through food chains.As we know,plants growth would be more significantly inhibited in acid soils than other soils if soil are contaminated by Pb.Therefore,remediation of Pb-contaminated soils is becoming a practical need for both environmental restoration and human health protection.We conducted a greenhouse experiment to compare the effects of various amendments(includes single superphosphate-SSP,calcium magnesium phosphate-CM,phosphate rock-RP,pig manure-PM, straw manure-SM,peat-PE) on forms and bioavailability of Pb in an acid red soil based on the responses of the two cultivars of vegetables to Pb stress.The main conclusion is as follows:The results showed that Red soil with Pb contamination could be remedied by several amendments,and the uptake of Pb in plants could be decreased.And significantly increase the biomass of plants.Two plants have different responses,the response of two cultivars of Brassica Chinensis with contrasting resistance to Pb is different.Biomass of Sijiqing plants was higher than that of Huangguan plants.It indicates that planting Pb-resistant veferables with soil amendments can effectively reduce Pb uptake by plants,therefore reduce the healthrisks to humans through food chains.The growth of two cultivars was affected by the bioavailable forms of Pb.Both soil pH and forms of Pb are important in remediation of acid soils with Pb contamination.The best treatment was calcium magnesium phosphate which immobilized Pb to more residual forms,and significantly reduced the uptake of Pb in plants.Most of the treatments reduce the Fe,Mn,Cu,Zn uptake by plants.For the soil with hard Pb contamination,these amendments can not reduce Pb uptake by two cultivars of vegetables to food safety limitis level.