摘要
分析了模拟Cr(Ⅵ)污水灌溉对水稻不同生育时期土壤微生物生物量及生物活性的影响,结果表明:(1)微生物生物量碳、生物量氮、基础呼吸作用、脲酶活性以及反硝化活性均与Cr(Ⅵ)灌溉浓度呈显著或极显著的负相关性,过氧化氢酶活性与Cr(Ⅵ)灌溉浓度呈显著或极显著的正相关,氨化作用在低浓度Cr(Ⅵ)(10mg·L-1)污灌下明显增强而在高浓度Cr(Ⅵ)(50mg·L-1)污灌下明显减弱;其中微生物生物量碳、生物量氮、基础呼吸强度以及脲酶活性与Cr(Ⅵ)灌溉浓度负相关性较好且在水稻各生育期均比较稳定,是水稻土Cr(Ⅵ)污染评价灵敏的生物学指标。(2)水稻不同生育时期土壤微生物生物量及生物活性对Cr(Ⅵ)污灌处理的敏感性存在差异,其中微生物生物量碳、生物量氮、反硝化活性、过氧化氢酶以及脲酶活性对Cr(Ⅵ)污灌敏感性总体上表现为生育前期高于生育后期。(3)加Si处理明显缓解Cr(Ⅵ)对土壤生物量碳、生物量氮、基础呼吸强度以及反硝化作用的抑制,但促进了Cr(Ⅵ)对土壤脲酶活力的抑制以及对土壤过氧化氢酶活力的刺激作用。
In order to understand the soil microbial biomass and bioactivity response to Cr（Ⅵ） stress in defferent growth stages of rice, pot experiment was conducted using the japonica cultivar Wuxiangjing 14, and irrigated with stimulated Cr（Ⅵ） sewage with three levels of concentration： 0 mg·L^-1（CK）, 10 mg·L^-1（Cr10） and 50 mg·L^-1（Cr50）. Results showed that： （1）There were significantly negative correlations between soil biomass carbon, biomass nitrogen, basal respiration, urease activity, denitflfication activity and the Cr（Ⅵ） concentration of sewage irrigated in the pots, whereas there was significantly positive correlation between soil eatalase activity and the Cr（Ⅵ） concentration of sewage irrigated in the pots, and the soil ammonifieation activity was promoted by Cr（Ⅵ） at lower concentration（Cr10）, but was inhibited at higher concen tration（Cr50）. Compared with other soil bioaetivity indexes, the soil biomass carbon, biomass nitrogen, basal respiration and urease activity were more correlative to the concentration ofCr（Ⅵ） and very stable daring whole treated stage, and could be as indicators of the Cr（Ⅵ） pollution degree in paddy soil. （2）The sensitivities of soil microbial biomass and bioactivity for Cr（Ⅵ） were varied with the growth stages of rice, in general, sensitivities of soil biomass carbon, biomass nitrogen, denitrification activity, urease activity and catalase aetivity for Cr（Ⅵ） were higher in early growth stage than in after growth stage. （3）Adding SiO2 into pot soil significantly decreased the inhibiting activity of Cr（Ⅵ） to soil biomass carbon, biomass nitrogen, basal respiration, and denitflfication activity, but it promoted the inhibiting activity of Cr（Ⅵ） to soil urease activity and the stimulating activity of Cr（Ⅵ） to catalase activity.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2008年第6期2308-2314,共7页
Journal of Agro-Environment Science
基金
国家自然科学基金面上项目(130470060
40471072)
