Provided for non-commercial research and education use. Not for reproduction, distribution or commercial use.

VOUUMC 163. NOS. t - S

I86N-O01& » $ l

IS JU N E £011

G

T JLJ.

A GW BALJOURNAL OF SOIL SCIENCE

A c o o [> frilirg iBurfvil o f tfio lUSS

This article appeared in a journai published by Elsevier. The attached copy is furnished to the author for internal non-com m ercial research and education use, including for instruction at the authors institution and sharing with colleagues. O ther uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party w ebsites are prohibited. in most cases authors are perm itted to post their version of the article (e.g. in Word or Tex form ) to their personal w ebsite or institutional repository. Authors requiring further inform ation regarding Elsevier’s archiving and m anuscript policies are encouraged to visit: http://ww w .eisevier.com /copyright

]

Geoderma 163 (2011) 135-140

C o n t e n t s l i sts avai l abl e at Scl e n c e Dl r e c t

Geoderma F IS H M F .

journal hom epage: w w w .e ls e v le r.c o m /lo c a te /g e o d e rm a

Estimating phosphorus availability for microbial growth in an emerging landscape S.K. Schmidt

CC. Cleveland

D.R. Nemergut ^ S.C Reed

A.J. King

P. Sowell

®Department o f Ecology &• Evolutionary Biology, University o f Colorado, Boulder 80309, USA Department o f Ecosystem & Conservation Sciences, University o f Montana, Missoula, M T 59812, USA ' Institute o f Arctic and Alpine Research, University o f Colorado, Boulder, Colorado 80309, USA US. Geological Survey, Southwest Biological Science Center, Moab, UT 84532, USA Ceomega, 2525 28th St., Suite 200, Boulder, CO 80301, USA

A R T I C L E

I N F O

Article history:

Received 10 July 2010 Received in revised form 14 March 2011 Accepted 9 April 2011 Keywords:

Biological weathering Phosphorus limitation

A B S T R A C T Estimating phosphorus (P) availability is difficult—particularly in infertile soils such as those exposed after glacial recession—because standard P extraction methods may not m imic biological acquisition pathways. We developed an approach, based on microbial CO2 production kinetics and conserved carbon:phosphorus (C:P) ratios, to estimate the amount 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, P additions stimulated the growth-related (logistic) kinetics of glutamate mineralization in soils that had been deglaciated from 0 to 5 years suggesting that microbial growth was lim ited by soil P availability. W e 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