不同价态外源硒对土壤硒形态及酶活性、微生物数量的影响  

Effects of Exogenous Selenium with Different Valences on Se Forms,Enzyme Activities and Microbial Quantity of Soil

作　　者：樊俊[1,2] 王瑞[2] 胡红青[1] 叶小江[2] 夏鹏亮[2] 邓建强[2] 

机构地区：[1]华中农业大学资源与环境学院,武汉430070 [2]湖北省烟草公司恩施州公司,湖北恩施445000

出　　处：《水土保持学报》2015年第5期137-141,171,共6页Journal of Soil and Water Conservation

基　　金：国家烟草专卖局科技项目"‘清江源’生态富硒特色烟叶生产关键技术研究与应用"(110201202014);湖北省烟草公司科技项目"恩施地区硒资源开发及在烟叶上的应用效果研究"(鄂烟科[2013]18号)

摘　　要：以植烟土壤为试材,采用盆栽试验的方法探讨了不同价态[Se(Ⅵ)和Se(Ⅳ)]和不同添加浓度(0mg/kg,2mg/kg,5mg/kg,10mg/kg,20mg/kg,30mg/kg)硒对土壤硒形态及酶活性、微生物数量的影响。研究结果表明:植烟土壤施用Se(Ⅵ),大部分硒以水溶态存在,部分被土壤矿物及腐殖质等吸附成为可交换态;施入的Se(Ⅳ)易被土壤吸附及被有机物和碳酸盐、铁锰氧化物结合而降低有效性。2种价态硒处理,土壤过氧化氢酶活性呈先增加再降低的趋势,脲酶活性和蔗糖酶活性呈降低的趋势,对中性磷酸酶活性影响不显著。适当浓度(5mg/kg和10mg/kg)2种价态硒有促进植烟土壤微生物数量增加的效果。通过相关性分析发现Se(Ⅵ)和Se(Ⅳ)对土壤蔗糖酶活性和脲酶活性有抑制效果(-0.905**和-0.915**;-0.873*和-0.537),可将土壤蔗糖酶活性和脲酶活性的降低作为Se(Ⅵ)污染的指标(极显著负相关),土壤蔗糖酶活性的降低作为Se(Ⅳ)污染的指标(显著负相关)。逐步回归分析表明,施入土壤的2种价态硒主要表现在水溶态硒对土壤酶活性的抑制。综合分析得出,土壤酶活性(主要为土壤蔗糖酶活性和脲酶活性)降低、土壤微生物(细菌和真菌)数量减少是硒污染导致土壤生态恶化的重要原因。In order to investigate the effects of exogenous selenium with different valences and concentrations（0mg/kg,2 mg/kg,5 mg/kg,10 mg/kg,20 mg/kg,and 30 mg/kg）of Se（Ⅵ）and Se（Ⅳ）on soil Se forms,enzyme activities and microbial quantity of soil,apot experiment was conducted in tobacco-planted soil.The results showed that,with the application of Se（Ⅵ）,most of selenium existed in the water-soluble state,and part of it existed in the exchangeable state because of absorption of soil minerals and humic substances,while Se（Ⅳ）applied in the soil was easily absorbed by soil,and decreased its effectiveness when combined with organic matter,carbonates and Fe-Mn oxides.Under the treatments of Se（Ⅵ）and Se（Ⅳ）,the catalase activities increased firstly and then reduced,but the activities of urease and sucrase decreased,and the neutral phosphate activities had no obvious changes.However,the treatments of both Se（Ⅵ）and Se（Ⅳ）with the appropriate concentration（5mg/kg to 10mg/kg）increased the soil microbial quantity.The correlation analysis indicated that there were negative effects of Se（Ⅵ）and Se（Ⅳ）on the soil sucrase and urease activities（-0.905＊＊and-0.915＊＊;-0.873＊and-0.537）.Hence,the pollution level of Se（Ⅵ）was determined by the decreasing level of soil sucrase and urease activities,while that of Se（Ⅳ）was determined by the decreasing level of sucrase activity.The stepwise regression analysis indicated that the water-soluble Se was the major limiting factor for soil enzyme activities.The decreases of soil enzyme（urease and sucrase activities）and microbial quantity（especially the number of bacteria and fungi）were important reasons for soil ecological deterioration induced by Se pollution.

关 键 词：硒 硒形态 土壤酶活性 土壤微生物 

分 类 号：S154.2[农业科学—土壤学]