Potential nitrogen immobilization as influenced by available carbon in Japanese arable and forest soils
Potential nitrogen immobilization as influenced by available carbon in Japanese arable and forest soils
复制标题
日本耕地和森林土壤中有效碳对潜在氮固定的影响
DOI：
10.1080/00380768.2015.1075364
复制
发表时间：
2015
影响因子：
2
通讯作者：
T.
中科院分区：
文献类型：
--
作者：
Sawada;K.;Funakawa;S.;Toyota;K.;Kosaki;T.
土壤中添加有机物料后，微生物对氮素的固定调节了土壤氮素的有效性，从而影响植物生长和氮素的淋溶。在这项研究中，微生物N固定的潜力进行了评估，通过短期培养实验后，有效碳（C）的非限制性条件下的N和磷（P）的7个日本耕地和森林土壤。以接近微生物生物质C的浓度添加葡萄糖作为模型底物。森林土壤有较低的pH值和较小的增加后，葡萄糖的呼吸速率，和较高的有机质和生物量C相比，耕地土壤。微生物氮固定，估计净减少可提取的N，是显着相关的葡萄糖浓度和平均43毫克N g− 1葡萄糖C在3和7天的培养过程中的所有土壤。生物量N的净增加量的氯仿熏蒸提取方法使用的共同转换因子为0.54，在3和7天后，葡萄糖添加低于微生物N固定的所有土壤，生物量N占固定N的耕地土壤中的一小部分比森林土壤。因此，本研究表明，微生物固定N将取决于有机物料中的有效C的浓度，并高于生物量N的增加，特别是对于耕地土壤，当有机物料添加到土壤中的非限制性条件下的N和P。
Microbial nitrogen (N) immobilization following the addition of organic materials to soils regulates soil N availability, which affects plant growth and N leaching from soils. In this study, the potential for microbial N immobilization was evaluated by short-term incubation experiments following the addition of available carbon (C) under non-limiting conditions of N and phosphorus (P) to seven Japanese arable and forest soils. Glucose was added as a model substrate at concentrations close to microbial biomass C. The forest soils had lower pH and smaller increases in respiration rates after the glucose addition, and higher organic and biomass C compared to the arable soils. Microbial N immobilization, estimated by net decreases in extractable N, was significantly correlated with the concentrations of added glucose and was on average 43 mg N g−1glucose C during 3- and 7-day incubation for all soils. Net increases in biomass N measured by the chloroform fumigation-extraction method using the common conversion factor of 0.54 at 3 and 7 days after the glucose addition were lower than the microbial N immobilization for all soils, and the biomass N accounted for a smaller portion of immobilized N in the arable soils than in the forest soils. Therefore, the present study suggests that microbial N immobilization would be dependent on the concentrations of available C in organic materials and higher than the increases in biomass N, especially for arable soils when organic materials are added to soils under non-limiting conditions of N and P.