Denitrification in Soil Profiles beneath Grassland and Cultivated Soils
Denitrification in Soil Profiles beneath Grassland and Cultivated Soils
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草地和耕地下土壤剖面的反硝化
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
C. Rice
中科院分区：
文献类型：
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作者：
D. Sotomayor;C. Rice
为了评估土壤N的最终去向，必须对底土和含水层的反硝化潜力进行表征。本试验旨在研究培养过程中反硝化细菌的地下分布和活性的变化。我们研究了草地和耕作条件下雷丁粉壤土(细粒、混合、中型Argiudoll)土壤的反硝化能力(N添加)和反硝化潜力(N+C添加)以及反硝化细菌数量的土壤剖面。在两个地点的土壤剖面亚表层均未检测到反硝化酶活性。总体而言，耕作地具有显著较高的NO3-浓度、反硝化菌种群和反硝化潜力。反硝化细菌在草原场地包气带中呈层状分布，地下水位界面的反硝化细菌数量最少，反硝化势最低。虽然C的添加促进了该地点的反硝化作用，但该剖面几乎不像耕作地点的那样受到C的限制。结果表明，在大约50年的时间里，增加氮素投入和种植改变了土壤包气带和饱和带的反硝化种群和反硝化潜力。
The denitrification potential of subsoils and aquifers must be characterized to assess the ultimate fate of soil N. This experiment was conducted to study changes in the subsurface distribution and activity of denitrifying bacteria as a result of cultivation. We examined soil profiles for their capacity (N addition) and potential (N + C addition) to denitrify as well as for denitrifying bacterial numbers in a Reading silt loam (fine, mixed, mesic Typic Argiudoll) soil under grassland and cultivation. Denitrifying enzyme activity was undetectable throughout the subsurface of soil profiles at both sites. Overall, the cultivated site had significantly higher NO 3 - concentrations, denitrifier populations, and denitrification potential. Denitrifying bacteria were stratified in the vadose zone at the prairie site, with lowest numbers and lowest denitrification potential occurring at the interface of the water table. Although C addition enhanced denitrifcation at this site, the profile was not nearly as limited by C as that of the cultivated site. The results demonstrated that increased N inputs and cultivation during approximately 50 yr changed the denitrifying population and denitrification potential in the vadose and saturated zones of soils.