不同土地利用方式下围垦海涂微生物群落和土壤酶特征

利用DGGE技术,从微生物多样性的角度,结合土壤酶活性研究不同农林利用方式对围垦海涂养分特征的影响。结果表明:未利用海涂盐分含量最高,而有机质和碱解氮含量最低;相比于蔬菜地和林地,棉花地和水稻田的有机质、碱解氮、过氧化氢酶和蛋白酶活性更高。四种利用方式土壤的脲酶和磷酸酶活性差异不显著。细菌是土壤中的主要种群,其数量与土壤有机质、碱解氮等养分特征呈显著正相关,表现为水稻田、棉花地>蔬菜地、林地>未利用。DGGE图谱分析结果显示未利用土壤shannon多样性指数最高为2.81,与水稻田、棉花地较为接近,其次为蔬菜地和林地,分别为2.52和2.38。围垦利用引起土壤中的Gaetbulibacter marinus与Gillisia mitskevichiae种属变化。围垦利用后土壤质量优于未利用海涂。相比而言,种植水稻对提高土壤肥力水平,维持土壤质量较为有利。

Characteristics of Microbial Community Structure and Enzyme Activities in Reclaimed Saline Soil Region under Different Land Use Types

The effects of land use types on soil nutrient in reclaimed saline soil were analyzed from the angle of microbial community diversity by DGGE and enzyme activities.Results showed soil salt content was the highest in newly reclaimed site where soil organic matter and available nitrogen were the lowest.Compared to vegetable field and wood land,soil organic matter and available nitrogen were higher in cotton field and paddy field,as well as catalase and protase activities.However,there were no significant differences in urase and phosphatase activities among four agriculture used land.Bacteria were the main microbial group in soil,which was significantly positive correlation to soil nutrients.The amounts of bacteria were in the order:paddy field and cotton field>vegetable field and wood land>newly reclaimed soil.Shannon diversity index of newly reclaimed soil microorganism was higher than that of other land use types(2.81).Among the four land use types,wood land had the lowest Shannon diversity index(2.38).Reclamation significantly affected the structural composition of bacterial community.The bands representing Gaetbulibacter marinus and Gillisia mitskevichiae were disappeared in wood land.To some extent,microbial diversity could be used to cluster soil with similar chemical quality.In conclusion,long-term reclamation has extremely positive effects on soil chemical properties and crop growth,which sheds light on differential impacts of land uses on soil enzyme activities and microbial community structure.Compared to other land use types,paddy field was benefit to improve and sustain soil quality.