Effects Of Lime And Organic Maters On Different Types Of Cadmium Contaminated Soils

Soil is the foundation of human existence and development of agriculture, but with therapid development of accelerated urbanization and industry and agriculture, soil pollutionespecially soil heavy metals pollution is getting worse. Physical, chemical, biological andecological measures are four main methods of restoration and management of cadmiumpolluted soils. Common chemical modifiers are alkaline substances and organic materials.Alkaline substances can increase soil pH, transfer heavy metals to carbonates and hydroxidesprecipitation, reduce the bioavailability of cadmium in the soil, thereby inhibit crop uptake ofCd; Organic material also have inhibition effect on the effectiveness of heavy metals in soil,and improving soil structure, soil nutrient regulation function. Currently, studies on differentrestoration methods to one nature of the cadmium contaminated soil are more, and on thesame modifier to the different nature of the cadmium contaminated soil are less.In this study, based on different soil organic matter and pH, four typical soils wereselected, named Latosolic red soil of Yunnan, red soil of Jiangxi, black soil of Jilin andchestnut soil of Inner Mongolia, designed to explore lime and organic materials’ differenceseffect on different nature of cadmium polluted soil, and to provide a theoretical basis to soilmodifier and remediation. The main findings are as follows:（1）For cadmium contaminated acid soil with low PH value and higher organic matter,such as Latosolic red soil of Yunnan, red soil of Jiangxi, black soil of Jilin, manure, peat andlime had a better improvement, but lime was better than the chicken manure and peat, whenchicken manure compared to peat, the former’ results slightly better than chicken peat;Chestnut soil in Inner Mongolia with low organic matter, high pH value and low cadmium,manure, peat and lime has a better improvement, and the effect of manure and peat better thanlime.（2）Owning to manure and peat’s high content of organic matter, it had a better effecton soil of low organic matter, such as chestnut soil in Inner Mongolia and Red Soil in Jiangxichestnut. Since chicken manure is more likely to decomposition, hence treatment of chickenmanure is easier to reach equilibrium than peat; while lime had a better improvement in acidcadmium polluted soil like Lateritic red soil in Yunnan and red soil in Jiangxi, and which was followed by neutral or alkaline soils like black soil in Jilin and chestnut soil in InnerMongolia.（3）Add modifiers can improve cabbage biomass, the organic material and limecombined application were better than the single application of organic materials or lime,between the two different combined application, lime+chicken manure was slightly betterthan lime+peat, but the difference was not significant; Single application of lime significantincrease the cabbage biomass in southern acid soil, but increase cabbage biomass in alkalinesoils on the northern effect slightly.（4）Whether it was applied organic materials or organic materials and lime combinesapplication, which can reduce cadmium of cabbage significantly, and organic materials andlime combined application had better results than single application of organic materials orlime; For South acidic soil, the effect of application of lime was better than organic materials.In the north alkaline soil, organic material’ effect was better than lime.（5）Single application of organic materials and lime or organic materials and limefertilizer can significantly reduced soil available cadmium content, and the effect of organicmaterials and Lime were better than the single application of organic materials and lime. ForLateritic red soil in Yunnan, red Soil in Jiangxi and black soil in Jilin, the effect of singleapplication of lime were better than that of single application of organic materials, and forchestnut soil in the Inner Mongolia, it was the single application of organic material had abetter effect than single application of lime.（6）Lateritic red soil in Yunnan and red soil in Jiangxi, in addition to peat processinghad little effect on soil pH, other various modifiers and compound modifiers had significanteffect on soil pH increase. The results of lime, manure+peat, peat+lime were better than thesingle application of manure. For black soil in Jilin and chestnut soil in Inner Mongolia, peatsoil treatment reduced the pH value, others improvers and complex modifiers improved thepH value significantly, the effect of lime, manure+lime and peat+lime were better than that ofsingle application chicken manure.