岩溶生态系统中土壤微生物量氮含量及其变化规律  

Contents of soil microbial biomass nitrogen and its change in Karst ecosystem

作　　者：申宏岗[1] 曹建华[1] 潘根兴[2] 

机构地区：[1]中国地质科学院岩溶地质研究所//国土资源部岩溶动力学开放实验室,广西桂林541004 [2]南京农业大学资源环境学院,江苏南京210095

出　　处：《生态环境》2007年第6期1728-1732,共5页Ecology and Environmnet

基　　金：国家自然科学基金项目(40372116);广西科学研究与技术开发计划项目"桂科能05112001-8A;桂科能063006-5H"

摘　　要：选择果树园和林地两种土地利用类型来研究土壤微生物量氮（Soil microbial biomass nitrogen,SMBN）含量及其与土壤溶解有机氮（Soil dissolved organic nitrogen,DON）、碱解氮的关系。结果表明：SMBN含量范围在5.33-34.61kg·hm^-2之间,平均为14.81kg·hm^-2,仅为文献中报道的SMBN的3%-37%。SMBN占土壤全氮的比例较小,为0.25%-1.5%,平均为0.754%。SMBN与DON及土壤有机碳等指标变化趋势一致。SMBN易矿化,与碱解氮关系密切,但由于岩溶山区这种特殊的生态环境,使得这种关系不像文献中报道的呈极强的正相关关系,这对于研究岩溶区特定条件下SMBN的变化以及对当地的土地利用类型有一定的参考价值和现实意义。As soil microorganisms decompose the organic matter, they also assimilate a portion of the nutrient in soils to build their body. The nutrients in soil microbial biomass are mineralized from the dead microorganisms. Therefore, soil microbial biomass is considered as a source and sinks for nutrients, and is an active pool of organic matter in soils. Because of its important role in various ecological systems, nitrogen contained in soil microbial biomass （i.e., SMBN） has got much attention in recent years, such as use the SMBN as an index to evaluate the effects of fertilization and tillage on soil properties. By far, there are still many issues to be resolved to understand the exact role of SMBN in N dynamics in soil plant systems. Many studies on soil microbial biomass nitrogen （SMBN） have been done in forest ecosystem, grassland ecosystem and agricultural ecosystem but in Karst ecosystem. SMBN is very sensitive to environment that can be affected by climate, vegetation, soil types and cultivation practices, and so on. Soils MBN, DON and available nitrogen and their relations have been studied in orchard and forest. The results indicated that the content of SMBN is between 5.33 kg·hm^-2 and 34.61 kg·hm^-2, the average is 14.81 kg·hm^-2, and the value is only 3%-37% of the other references reported. SMBN/TN （total nitrogen） is between 0.25%-1.5%, the average is 0.754%. The value of SMBN keeps accord with DON and SOC that is they change with similar trends. SMBN mineralized easily, but there is no significant positive correlation with available nitrogen just as other references reported,so this article can provide some clues for further research and also practical applications for plantation.

关 键 词：岩溶生态系统 土壤微生物量氮 变化规律 

分 类 号：S154.3[农业科学—土壤学]