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Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Impacts of nutrient addition on soil carbon and nitrogen stoichiometry and stability in globally-distributed grasslands
AU - Rocci, K.S.
AU - Barker, Kaydee S.
AU - Seabloom, Eric W.
AU - Borer, E.T.
AU - Hobbie, Sarah
AU - Bakker, Jonathan D.
AU - MacDougall, A.S.
AU - Mcculley, Rebecca
AU - Moore, J.L.
AU - Raynaud, X.
AU - Stevens, Carly
AU - Cotrufo, Francesca
N1 - The final publication is available at Springer via http://dx.doi.org/10.1007/s10533-022-00932-w
PY - 2022/7/31
Y1 - 2022/7/31
N2 - Global changes will modify future nutrient availability with implications for grassland biogeochemistry. Soil organic matter (SOM) is central to grasslands for both provision of nutrients and climate mitigation through carbon (C) storage. While we know that C and nitrogen (N) in SOM can be influenced by greater nutrient availability, we lack understanding of nutrient effects on C and N coupling and stability in soil. Different SOM fractions have different functional relevance and mean residence times, i.e., mineral-associated organic matter (MAOM) has a higher mean residence time than particulate organic matter (POM). By separating effects of nutrient supply on the different SOM fractions, we can better evaluate changes in soil C and N coupling and stability and associated mechanisms. To this end, we studied responses of C and N ratios and distributions across POM and MAOM to 6–10 years of N, phosphorus (P), potassium and micronutrients (K+µ), and combined NPK+µ additions at 11 grassland sites spanning 3 continents and globally relevant environmental gradients in climate, plant growth, soil texture, and nutrient availability. We found addition of N and NPK+µ generally reduced C:N in MAOM and POM. However, at low fertility and at warm, sandy sites, nutrient addition promoted higher MAOM and POM C:N, respectively. Addition of NPK+µ also promoted C storage in POM relative to MAOM, and this was consistent across sites. Our results suggest that addition of macro- and micronutrients consistently decrease SOM stabilization, whereas responses of soil C:N stoichiometry were contingent on SOM fraction and environmental conditions.
AB - Global changes will modify future nutrient availability with implications for grassland biogeochemistry. Soil organic matter (SOM) is central to grasslands for both provision of nutrients and climate mitigation through carbon (C) storage. While we know that C and nitrogen (N) in SOM can be influenced by greater nutrient availability, we lack understanding of nutrient effects on C and N coupling and stability in soil. Different SOM fractions have different functional relevance and mean residence times, i.e., mineral-associated organic matter (MAOM) has a higher mean residence time than particulate organic matter (POM). By separating effects of nutrient supply on the different SOM fractions, we can better evaluate changes in soil C and N coupling and stability and associated mechanisms. To this end, we studied responses of C and N ratios and distributions across POM and MAOM to 6–10 years of N, phosphorus (P), potassium and micronutrients (K+µ), and combined NPK+µ additions at 11 grassland sites spanning 3 continents and globally relevant environmental gradients in climate, plant growth, soil texture, and nutrient availability. We found addition of N and NPK+µ generally reduced C:N in MAOM and POM. However, at low fertility and at warm, sandy sites, nutrient addition promoted higher MAOM and POM C:N, respectively. Addition of NPK+µ also promoted C storage in POM relative to MAOM, and this was consistent across sites. Our results suggest that addition of macro- and micronutrients consistently decrease SOM stabilization, whereas responses of soil C:N stoichiometry were contingent on SOM fraction and environmental conditions.
KW - Nutrient network (NutNet)
KW - Soil organic matter
KW - Nutrient addition
KW - · Mineral-associated organic matter
KW - Particulate organic matter
KW - Grasslands
KW - Nitrogen
KW - Phosphorous
KW - Potaassium
UR - http://www.scopus.com/inward/record.url?scp=85130209266&partnerID=8YFLogxK
U2 - 10.1007/s10533-022-00932-w
DO - 10.1007/s10533-022-00932-w
M3 - Journal article
VL - 159
SP - 353
EP - 370
JO - Biogeochemistry
JF - Biogeochemistry
SN - 0168-2563
IS - 3
ER -