TY - JOUR
T1 - Nitrogen and Phosphorus Additions Alter the Abundance of Phosphorus-Solubilizing Bacteria and Phosphatase Activity in Grassland Soils
AU - Widdig, Meike
AU - Schleuss, Per M.
AU - Weig, Alfons R.
AU - Guhr, Alexander
AU - Biederman, Lori A.
AU - Borer, Elizabeth T.
AU - Crawley, Michael J.
AU - Kirkman, Kevin P.
AU - Seabloom, Eric W.
AU - Wragg, Peter D.
AU - Spohn, Marie
N1 - Publisher Copyright:
© Copyright © 2019 Widdig, Schleuss, Weig, Guhr, Biederman, Borer, Crawley, Kirkman, Seabloom, Wragg and Spohn.
PY - 2019/11/26
Y1 - 2019/11/26
N2 - Microorganisms mobilize phosphorus (P) in soil by solubilizing bound inorganic P from soil minerals and by mineralizing organic P via phosphatase enzymes. Nitrogen (N) inputs are predicted to increase through human activities and shift plants to be more P limited, increasing the importance of P mobilization processes for plant nutrition. We studied how the relative abundance of P-solubilizing bacteria (PSB), PSB community composition, and phosphatase activity respond to N and P addition (+N, +P, +NP) in grassland soils spanning large biogeographic gradients. The studied soils are located in South Africa, USA, and UK and part of a globally coordinated nutrient addition experiment. We show that the abundance of PSB in the topsoil was reduced by −18% in the N and by −41% in the NP treatment compared to the control. In contrast, phosphatase activity was significantly higher in the N treatment than in the control across all soils. Soil C:P ratio, sand content, pH, and water-extractable P together explained 71% of the variance of the abundance of PSB across all study sites and all treatments. Further, the community of PSB in the N and NP addition treatment differed significantly from the control. Taken together, this study shows that N addition reduced the relative abundance of PSB, altered the PSB community, and increased phosphatase activity, whereas P addition had no impact. Increasing atmospheric N deposition may therefore increase mineralization of organic P and decrease solubilization of bound inorganic P, possibly inducing a switch in the dominant P mobilization processes from P solubilization to P mineralization.
AB - Microorganisms mobilize phosphorus (P) in soil by solubilizing bound inorganic P from soil minerals and by mineralizing organic P via phosphatase enzymes. Nitrogen (N) inputs are predicted to increase through human activities and shift plants to be more P limited, increasing the importance of P mobilization processes for plant nutrition. We studied how the relative abundance of P-solubilizing bacteria (PSB), PSB community composition, and phosphatase activity respond to N and P addition (+N, +P, +NP) in grassland soils spanning large biogeographic gradients. The studied soils are located in South Africa, USA, and UK and part of a globally coordinated nutrient addition experiment. We show that the abundance of PSB in the topsoil was reduced by −18% in the N and by −41% in the NP treatment compared to the control. In contrast, phosphatase activity was significantly higher in the N treatment than in the control across all soils. Soil C:P ratio, sand content, pH, and water-extractable P together explained 71% of the variance of the abundance of PSB across all study sites and all treatments. Further, the community of PSB in the N and NP addition treatment differed significantly from the control. Taken together, this study shows that N addition reduced the relative abundance of PSB, altered the PSB community, and increased phosphatase activity, whereas P addition had no impact. Increasing atmospheric N deposition may therefore increase mineralization of organic P and decrease solubilization of bound inorganic P, possibly inducing a switch in the dominant P mobilization processes from P solubilization to P mineralization.
KW - Nutrient Network (NutNet)
KW - enzyme activity
KW - nitrogen fertilization
KW - phosphate solubilization
KW - phosphorus cycling
KW - phosphorus mineralization
KW - phosphorus mobilization
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U2 - 10.3389/fenvs.2019.00185
DO - 10.3389/fenvs.2019.00185
M3 - Article
AN - SCOPUS:85076698900
SN - 2296-665X
VL - 7
JO - Frontiers in Environmental Science
JF - Frontiers in Environmental Science
M1 - 185
ER -