【摘要】 为了降低叶菜中重金属Pb的含量,选择有机肥、猪粪、牛粪、鸡粪和花生麸5种有机物料为材料,分别以0.5%、1%、2%、4%4个水平的用量施入重金属污染土壤,通过种植3茬生菜(Lactuca sativa L.)的盆栽试验研究有机物料对重金属污染土壤上生菜生长及其Pb含量的影响。结果表明,与对照相比,有机物料利于生菜生长,有提高生菜生物量的趋势;大部分有机物料处理没有显著影响生菜地上部分的Pb含量;5种有机物料中,仅牛粪有提高生菜地上部Pb含量的趋势;生菜Pb含量平均值高低的顺序为牛粪>鸡粪>花生麸>有机肥>猪粪,但不同有机物料之间没有显著差异。与对照相比,大部分处理没有显著影响土壤的DTPA-Pb含量,初步揭示了供试有机物料没有显著影响生菜地上部Pb含量的原因。更多还原

【Abstract】 There is increasing concern about vegetable safety and environmental heavy metal pollution in the rapidly developing suburb in China, especially in the Pearl River Delta Region, South China. The bioavailability of heavy metals can decrease due to their immobilization by adsorption or binding to organic matter with high molecule weight in soils. Therefore, addition of organic materials to soils may reduce the uptake of heavy metals by crops. Three continuous rounds of pot experiment were conducted to investigated the effect of five organic materials(manure, pig shit, cattle shit, hen shit, earthnut residue, and their application of 0.5%, 1%, 2%, 4% per kg soil, respectively) on the growth and Pb concentrations of lettuce(Lactuca sativa). The results showed that compared with the control, organic materials were beneficial for the growth of lettuce and increased the fresh biomass of lettuce; The growth response of lettuce growing in the soil to five organic material wasn’t unanimous, which were in the order of hen shit>earthnut residue>pig shit>cattle shit>manure. Most of treatments affected insignificantly aboveground Pb concentration of lettuce in comparison with CK. Among 5 organic materials, only cattle shit had a trend to increase the Pb uptake of lettuce. The aboveground Pb concentration mean values of 5 organic materials for 3 crops lettuce were different(cattle shit>hen shit>earthnut residue>manure>pig shit), but there was not markedly difference among them. The effect of 5 organic materials on soil pH was different. There was a significantly negative relationship between treatment dose of manure(or earthnut residue) and soil pH(Pearson correlation:-0.820、-0.917, N=20, P<0.01):There was insignificant relationship between that of hen shit and soil pH; But there was markedly positive relationship between that of pig shit(or cattle shit) and soil pH(0.862, 0.775, N=20, P<0.01). DTPA-Pb was significantly negatively related to soil pH, but it was insignificantly related to aboveground Pb concentration. Compared with CK, most of treatments did not affect significantly soil DTPA-Pb concentration, so the preliminary reason is disclosed why the tested organic materials did not affect remarkably aboveground Pb concentration of L. sativa.更多还原