Increased N availability in grassland soils modifies their microbial communities and decreases the abundance of arbuscular mycorrhizal fungi

Bradley, K; Drijber, RA; Knops, J

HERO ID

455562

Reference Type

Journal Article

Year

2006

Language

English

HERO ID 455562
In Press No
Year 2006
Title Increased N availability in grassland soils modifies their microbial communities and decreases the abundance of arbuscular mycorrhizal fungi
Authors Bradley, K; Drijber, RA; Knops, J
Journal Soil Biology and Biochemistry
Volume 38
Issue 7
Page Numbers 1583-1595
Abstract Two complementary studies were performed to examine (1) the effect of 18 years of nitrogen (N) fertilization, and (2) the effects of N fertilization during one growing season on soil microbial community composition and soil resource availability in a grassland ecosystem. N was added at three different rates: 0, 5.44, and 27.2g N m(-2) y(-1). In both studies, Schizachyrium scoparium was the dominant plant species before N treatments were applied. Soil microbial communities from each experiment were characterized using fatty acid methyl ester (FAME) analysis. Discriminant analysis of the FAMEs separated the three N fertilizer treatments in both experiments, indicating shifts in the composition of the microbial communities. In general, plots that received N fertilizer at low or high application rates for 18 years showed increased proportions of bacterial FAMEs and decreased fungal FAMEs. In particular, control plots contained a significantly higher proportion of fungal FAMEs C18:1(cis9) and C18:2(cis9,12) and of the arbuscular mycorrhizal fungal (AMF) FAME, C16:1 (cis11), than both of the N addition treatment plots. A significant negative effect of N fertilization on the AMF FAME, C16:1 (cis11), was measured in the short-term experiment. Our results indicate that high rates of anthropogenic N deposition can lead to significant changes in the composition of soil microbial communities over short periods and can even disrupt the relationship between AMF and plants.
Doi 10.1016/j.soilbio.2005.11.011
Wosid WOS:000239946100009
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English
Keyword arbuscular mycorrhizal fungi; fame; microbial community composition; nitrogen fertilization; grasslands
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