改良剂对土壤锌铅生物有效性及其在玉米中累积状况研究

Effects of Soil Amendments on Soil Zn and Pb Bioavailability and Their Accumulation in Maize

采用盆栽实验研究不同改良剂组合对广西岩溶地区铅锌矿区周边铅锌污染农田土壤中铅锌赋存形态及玉米吸收、累积铅锌的影响。结果表明,改良剂处理均显著提高玉米生物量和籽粒产量,显著降低玉米各部位Zn、Pb的含量及其富集系数,显著降低Zn由根系向茎叶的转运系数,而只有石灰+胡敏酸钠处理显著降低Zn由根系向籽粒的转运系数。5种改良剂处理均显著提高土壤p H值,降低土壤中Zn、Pb的水溶态、可交换态和碳酸盐结合态和铁/锰氧化物结合态含量及比例,增加有机物及硫化物结合态和残渣态含量及比例。总体上,改良效应表现为:石灰+胡敏酸钠+硅肥+海泡石>石灰+胡敏酸钠+硅肥>石灰+胡敏酸钠+海泡石>石灰+胡敏酸钠>石灰。相关分析结果表明,玉米体内Zn的含量与土壤p H无显著相关(P<0.05),但玉米体内Pb的含量与土壤p H呈极显著负相关(P<0.01)。玉米体内Zn、Pb的含量均与土壤中Zn、Pb的水溶态、可交换态和碳酸盐结合态的比例呈极显著正相关(P<0.01),相关系数分别为0.967和0.979。

A pot experiment was carried out to investigate the effects of different amendments on soil Zn,Pb species and accumulation of Zn,Pb in maize in Zn,Pb contaminated farmland around a lead-zinc mining area of Guangxi,China. The results showed that the addition of amendments could significantly increase the biomass and yield of maize,and significantly decrease the accumulations of Zn and Pb in different parts of maize,significantly decrease transportations of Zn from roots to stem and leaves,while the transportations of Zn from roots to grains were significantly decreased with the treatment of lime ＋ soudium humate. The five amendments significantly increased soil p H,decreased the contents of dissoived,exchangeable and bound to carbonate and bound to iron and manganese oxides of soil Zn and Pb,increased the contents of bound to organic and sulphidic matter,residue of soil Zn and Pb. In general,the improving effects of amendments addition were lime＋ soudium humate ＋ silicon fertilizer ＋ sepiolite 〉lime ＋ soudium humate ＋ silicon fertilizer 〉lime ＋ soudium humate ＋ sepiolite 〉lime ＋ soudium humate 〉lime 〉CK. The correlation analysis showed that there was no correlation between the contents of Zn in maize and soil p H（ P〈0. 05）,while the contents of Pb in maize was significantly negative correlation with p H（ P〈0. 01）. It was significantly positive correlation between the contents of Zn,Pb in maize with dissoived,exchangeable and bound to carbonate of soil Zn,Pb（ P〈0. 01）,their correlation coefficient were 0. 967 and 0. 979,respectively.