Zeng Lu-Sheng, Liao Min, Chen Cheng-Li, Huang Chang-Yong
Department of Resources Science, College of Environmental and Resources Sciences, Zhejiang University, Kaixuan Road 268, Hangzhou, Zhejiang Province 310029, China.
Chemosphere. 2006 Oct;65(4):567-74. doi: 10.1016/j.chemosphere.2006.02.039. Epub 2006 Apr 11.
The effect of lead (Pb) treatment on the soil microbial activities (soil microbial biomass and soil basal respiration) and rice physiological indices were studied by greenhouse pot experiment. Pb was applied as lead acetate at six different levels in two different paddy soils, namely 0 (control), 100, 300, 500, 700, 900 mg kg-1 soil. The results showed that the application of Pb at lower level (<300 mg kg-1) as lead acetate resulted in a slight increase in soil microbial activities compared with the control, and had an inhibitory influence at high concentration (>500 mg Pb kg-1 soil), which might be the critical concentration of Pb causing a significant decline in the soil microbial activities. However, the degree of influence on soil microbial activities by Pb was related to the clay and organic matter contents of the soils. On the other hand, when the level of Pb treatments increased to 500 mg kg-1, there was ecological risk for both soil microbial activities and plants. The results also revealed that there was a consistent trend that the chlorophyll contents increased initially, and then decreased gradually with increase in Pb concentration. Pb was effective in inducing proline accumulation and its toxicity causes oxidative stress in rice plants. In a word, soil microbial activities and rice physiological indices, therefore, may be sensitive indicators reflecting environmental stress in soil-Pb-rice system.
通过温室盆栽试验研究了铅（Pb）处理对土壤微生物活性（土壤微生物生物量和土壤基础呼吸）及水稻生理指标的影响。在两种不同的水稻土中，以醋酸铅的形式设置了六个不同水平的Pb添加量，分别为0（对照）、100、300、500、700、900 mg kg-1土壤。结果表明，与对照相比，较低水平（<300 mg kg-1）的醋酸铅添加导致土壤微生物活性略有增加，而在高浓度（>500 mg Pb kg-1土壤）时具有抑制作用，这可能是导致土壤微生物活性显著下降的Pb临界浓度。然而，Pb对土壤微生物活性的影响程度与土壤的黏土和有机质含量有关。另一方面，当Pb处理水平增加到500 mg kg-1时，土壤微生物活性和植物均存在生态风险。结果还表明，随着Pb浓度的增加，叶绿素含量呈现先增加后逐渐降低的一致趋势。Pb能有效诱导脯氨酸积累，其毒性会导致水稻植株产生氧化应激。总之，土壤微生物活性和水稻生理指标可能是反映土壤 - Pb - 水稻系统环境胁迫的敏感指标。
