Plant-microbial competition for nitrogen uncoupled from soil C:N ratios
(2009) In Oikos 118(12). p.1908-1916- Abstract
- A green house experiment was designed to test the idea that competition for inorganic nitrogen (N) between plants and heterotrophic microorganisms occurs in soils with high C:N ratios, qualifying for N limited microbial activity, but not at low C:N ratios. The short- term (24 h) N-15 uptake by the grass Festuca gigantea and microorganisms in planted and unplanted soils was determined, and the bacterial activity was measured by the H-3-thymidine incorporation technique. Two deciduous forest soils, with C:N-ratios of 20 and 31, and the 20 soil amended with litter to a C:N ratio of 34, were used. A novel and important part of the experimental design was the preparation of the unplanted reference soil with plants present until the competition... (More)
- A green house experiment was designed to test the idea that competition for inorganic nitrogen (N) between plants and heterotrophic microorganisms occurs in soils with high C:N ratios, qualifying for N limited microbial activity, but not at low C:N ratios. The short- term (24 h) N-15 uptake by the grass Festuca gigantea and microorganisms in planted and unplanted soils was determined, and the bacterial activity was measured by the H-3-thymidine incorporation technique. Two deciduous forest soils, with C:N-ratios of 20 and 31, and the 20 soil amended with litter to a C:N ratio of 34, were used. A novel and important part of the experimental design was the preparation of the unplanted reference soil with plants present until the competition assay started by the addition of N-15 labelled ammonium (NH4+) or nitrate (NO3-). The results suggested that plants and soil microorganisms competed for mineral N but under influence of other factors than the soil C:N ratio. The plants reduced the microbial uptake of NH4+ and NO3- in the soil with low C:N ratio, which also had the lowest bacterial activity. The plants had a larger N uptake than microorganisms in the two natural soils but smaller in the litter-amended, and their presence enhanced the bacterial activity, especially in the latter soil. The litter-amended soil with its high C:N ratio and easily decomposable C was the soil that best fulfilled the criteria for competition, including a net consumption of mineral N during the assay, the lowest plant uptake of mineral N due to the high N immobilization by microorganisms, and a reduced microbial N-15 uptake-to-bacterial activity in the presence of plants. Thus, other factors, such as the decomposability of the soil C and the bacterial activity, were more important than the soil C:N ratio to the outcome of plant-microbial competition for N. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1533402
- author
- Månsson, Katarina LU ; Bengtson, Per LU ; Falkengren-Grerup, Ursula LU and Bengtsson, Göran LU
- organization
- publishing date
- 2009
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Oikos
- volume
- 118
- issue
- 12
- pages
- 1908 - 1916
- publisher
- Wiley-Blackwell
- external identifiers
-
- wos:000272306900016
- scopus:71049132172
- ISSN
- 1600-0706
- DOI
- 10.1111/j.1600-0706.2009.17796.x
- language
- English
- LU publication?
- yes
- id
- 596b537d-65e8-4ae1-8390-ed4cfd9ec309 (old id 1533402)
- date added to LUP
- 2016-04-01 12:10:36
- date last changed
- 2024-05-08 05:49:43
@article{596b537d-65e8-4ae1-8390-ed4cfd9ec309,
abstract = {{A green house experiment was designed to test the idea that competition for inorganic nitrogen (N) between plants and heterotrophic microorganisms occurs in soils with high C:N ratios, qualifying for N limited microbial activity, but not at low C:N ratios. The short- term (24 h) N-15 uptake by the grass Festuca gigantea and microorganisms in planted and unplanted soils was determined, and the bacterial activity was measured by the H-3-thymidine incorporation technique. Two deciduous forest soils, with C:N-ratios of 20 and 31, and the 20 soil amended with litter to a C:N ratio of 34, were used. A novel and important part of the experimental design was the preparation of the unplanted reference soil with plants present until the competition assay started by the addition of N-15 labelled ammonium (NH4+) or nitrate (NO3-). The results suggested that plants and soil microorganisms competed for mineral N but under influence of other factors than the soil C:N ratio. The plants reduced the microbial uptake of NH4+ and NO3- in the soil with low C:N ratio, which also had the lowest bacterial activity. The plants had a larger N uptake than microorganisms in the two natural soils but smaller in the litter-amended, and their presence enhanced the bacterial activity, especially in the latter soil. The litter-amended soil with its high C:N ratio and easily decomposable C was the soil that best fulfilled the criteria for competition, including a net consumption of mineral N during the assay, the lowest plant uptake of mineral N due to the high N immobilization by microorganisms, and a reduced microbial N-15 uptake-to-bacterial activity in the presence of plants. Thus, other factors, such as the decomposability of the soil C and the bacterial activity, were more important than the soil C:N ratio to the outcome of plant-microbial competition for N.}},
author = {{Månsson, Katarina and Bengtson, Per and Falkengren-Grerup, Ursula and Bengtsson, Göran}},
issn = {{1600-0706}},
language = {{eng}},
number = {{12}},
pages = {{1908--1916}},
publisher = {{Wiley-Blackwell}},
series = {{Oikos}},
title = {{Plant-microbial competition for nitrogen uncoupled from soil C:N ratios}},
url = {{http://dx.doi.org/10.1111/j.1600-0706.2009.17796.x}},
doi = {{10.1111/j.1600-0706.2009.17796.x}},
volume = {{118}},
year = {{2009}},
}