Rights statement: This is the author’s version of a work that was accepted for publication in Soil Biology and Biocheistry. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Soil Biology and Biochemistry, 149, 2020 DOI: 10.1016/j.soilbio.2020.107962
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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Chronic nitrogen addition differentially affects gross nitrogen transformations in alpine and temperate grassland soils
AU - Hao, T.
AU - Zhang, Y.
AU - Zhang, J.
AU - Müller, C.
AU - Li, K.
AU - Zhang, K.
AU - Chu, H.
AU - Stevens, C.
AU - Liu, X.
N1 - This is the author’s version of a work that was accepted for publication in Soil Biology and Biocheistry. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Soil Biology and Biochemistry, 149, 2020 DOI: 10.1016/j.soilbio.2020.107962
PY - 2020/10/1
Y1 - 2020/10/1
N2 - Nitrogen (N) deposition can profoundly alter soil N cycling of grassland ecosystems. Substrates and soil acidification are expected to modify soil N transformations in response to elevated N deposition. Here, we carried out 15N tracing studies to test the effects of N addition rates (low: 30 kg N ha−1 and high: 90/120 kg N ha−1) and soil acidification on gross N transformation rates using two typical Chinese grassland soils, an alpine calcareous soil and a temperate neutral soil. We found that N addition significantly increased the ratio of gross nitrification rate to gross ammonia immobilization rate (N/I) in both soils, but gross N transformation rates changed differently as a function of N addition rates and soil types. In the calcareous soil, N addition increased soil gross N transformations, largely due to mineral N substrates, SOC, TN and fungal dominance. In contrast, low N addition did not affect gross N transformation rates in the neutral soil, but high N addition significantly decreased gross N transformation rates. Although both SOC and TN were increased with N addition in the neutral soil, N-induced soil pH decline decreased gross N transformation rates. Our results indicate that the effects of N addition on grassland soil gross N transformations are highly dependent on mineral N substrates, SOC and TN. Soil acidification played a more important role than SOC and TN in gross N transformation rate changes in response to elevated N deposition. These findings suggest that the different changes of gross N transformation rates in response to N deposition and soil properties (e.g. SOC, TN and soil pH) should be integrated into biogeochemical models to better predict grassland ecosystem N cycling in the future scenarios of N deposition.
AB - Nitrogen (N) deposition can profoundly alter soil N cycling of grassland ecosystems. Substrates and soil acidification are expected to modify soil N transformations in response to elevated N deposition. Here, we carried out 15N tracing studies to test the effects of N addition rates (low: 30 kg N ha−1 and high: 90/120 kg N ha−1) and soil acidification on gross N transformation rates using two typical Chinese grassland soils, an alpine calcareous soil and a temperate neutral soil. We found that N addition significantly increased the ratio of gross nitrification rate to gross ammonia immobilization rate (N/I) in both soils, but gross N transformation rates changed differently as a function of N addition rates and soil types. In the calcareous soil, N addition increased soil gross N transformations, largely due to mineral N substrates, SOC, TN and fungal dominance. In contrast, low N addition did not affect gross N transformation rates in the neutral soil, but high N addition significantly decreased gross N transformation rates. Although both SOC and TN were increased with N addition in the neutral soil, N-induced soil pH decline decreased gross N transformation rates. Our results indicate that the effects of N addition on grassland soil gross N transformations are highly dependent on mineral N substrates, SOC and TN. Soil acidification played a more important role than SOC and TN in gross N transformation rate changes in response to elevated N deposition. These findings suggest that the different changes of gross N transformation rates in response to N deposition and soil properties (e.g. SOC, TN and soil pH) should be integrated into biogeochemical models to better predict grassland ecosystem N cycling in the future scenarios of N deposition.
KW - 15N tracing technology
KW - Grassland
KW - Gross N transformations
KW - Nitrogen deposition
KW - Soil acidification
KW - Acidification
KW - Ammonia
KW - Deposition
KW - Ecosystems
KW - Forestry
KW - Nitrogen
KW - Soil testing
KW - Biogeochemical models
KW - Grassland ecosystems
KW - Gross nitrification
KW - Immobilization rates
KW - N transformation rates
KW - Nitrogen transformations
KW - Soil acidifications
KW - Temperate grasslands
KW - Soils
U2 - 10.1016/j.soilbio.2020.107962
DO - 10.1016/j.soilbio.2020.107962
M3 - Journal article
VL - 149
JO - Soil Biology and Biochemistry
JF - Soil Biology and Biochemistry
SN - 0038-0717
M1 - 107962
ER -