Bacterial growth and growth-limiting nutrients following chronic nitrogen additions to a hardwood forest soil
Abstract
Increasing nitrogen (N) deposition due to anthropogenic activities has become a significant global change threat to N-poor terrestrial ecosystems. We compared bacterial growth and nutrients limiting bacterial growth in one of the longest running experiments on increasing N-deposition to a temperate forest, the Chronic Nitrogen Amendment Study at Harvard Forest, USA. Soil samples were collected in fall 2009 from the organic and mineral horizons of plots treated annually since 1988 with 0 (unfertilized), 50 (low N) or 150 (high N) kg N ha−1 as NH4NO3. In the organic horizon, bacterial growth (leucine incorporation) decreased by 5 times in the high N plots compared to the unfertilized treatment, while no decrease was observed in the mineral horizon. Bacterial growth in all soils was primarily limited by lack of carbon (C), although adding only C (as glucose) resulted in only a minor increase in bacterial growth in the unfertilized soil compared to adding C in combination with N. The bacterial growth induced by adding only C increased with higher level of N fertilization, up to 7–8 times the level without any C addition in the high N treatment, suggesting increased availability of N for the bacteria with increasing N addition.
Department
Soil Biogeochemistry and Microbial Ecology
Publication Date
1-22-2013
Journal Title
Soil Biology and Biochemistry
Publisher
Elsevier
Digital Object Identifier (DOI)
Document Type
Article
Recommended Citation
Pramod N. Kamble, Johannes Rousk, Serita D. Frey, Erland Baath, Bacterial growth and growth-limiting nutrients following chronic nitrogen additions to a hardwood forest soil, Soil Biology and Biochemistry, Volume 59, 2013, Pages 32-37, ISSN 0038-0717, https://doi.org/10.1016/j.soilbio.2012.12.017.
Rights
© 2013 Elsevier Ltd. All rights reserved.