Schmidt,S.K., Cleveland,C.C., Nemergut,D.R., Reed,S.C., King,A.J. and Sowell,P.(2011): Estimating phosphorus availability for microbial growth in an emerging landscape. Geoderma, 163, 135-140.

『出現している景観における微生物の成長に役立つリンを見積る』


Abstract
 Estimating phosphorus (P) availability is difficult - particularly in infertile soils such as those exposed after glacial recession - because standard P extraction methods may not mimic biological acquisition pathways. We developed an approach, based on microbial CO2 production kinetics and conserved carbon:phosphorus (C:P) ratios, to estimate the mount of P available for microbial growth in soils and compared this method to traditional, operationally-defined indicators of P availability. Along a primary succession gradient in the High Andes of Peru(uの頭に´), P additions simulated the growth-related (logistic) kinetics of glutamate mineralization in soils that had been deglaciated from 0 to 5 years suggesting that microbial growth was limited by soil P availability. We then used a logistic model to estimate the amount of C incorporated into biomass in P-limited soils, allowing us to estimate total microbial P uptake based on a conservative C:P ratio of 28:1 (mass;mass). Using this approach, we estimated that there was<1μg/g of microbial-available P in recently de-glaciated soils in both years of this study. These estimates fell well below estimates of available soil P obtained using traditional extraction procedures. Our results give both theoretical and practical insights into the kinetics of C and P utilization in young soils, as well as show changes in microbial P availability during early stages of soil development.

Keywords: Biological weathering; Phosphorus limitation』

1. Introduction
2. Methods
 2.1. Study sites
 2.2. Soil P fractions
 2.3. Microbial kinetics
 2.4. Estimating soil P using microbial kinetics
 2.5. Estimating microbial growth rates
 2.6. Statistics
3. Results
4. Discussion
5. Conclusion
Acknowledgements
References


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