permaculture

["Lawrence F. London, Jr." <lflj@bellsouth.net>]

-------- Original Message --------
Subject: [SANET-MG] Breakdown of Phsphate in the soil
Date: Thu, 11 Nov 2010 12:07:41 -0800
From: Carl DuPoldt <cdupoldt@YAHOO.COM>
To: SANET-MG@LISTS.IFAS.UFL.EDU

http://www.ars.usda.gov/research/publications/publications.htm?seq_no_115=240627

Technical Abstract: Inorganic and organic phosphates react strongly with soil constituents, resulting in relatively low 
concentrations of soluble P in the soil solution. Multiple competing reactions are operating to regulate the 
solution-phase concentration of P-containing organic substrates and the released phosphate for assimilation by microbes, 
plants, or dispersal in the environment. In intensive agrosystems, external inputs of commercial fertilizers are often 
required to attain sufficiency levels of plant-available P. In this chapter, we focus on the ligand exchange process 
involved in the solubilization of organic P, a forerunner process crucial to the function of extracellular 
phosphohydrolases in accessing the recalcitrant soil organic P pool. Plants and microorganisms have evolved and 
developed multiple strategies to obtain needed P. In these strategies, frequent interweaving of biophysical and 
biochemical processes are observed in the
 mineralization of organic P forms. A fundamental reassessment of the biogeochemistry of P in the soil-water systems is 
necessary to improve our understanding of the physical chemistry of charged surfaces and the role of organic ligands in 
the turnover of stabilized organic P. Practical solutions to constraints to phosphohydrolases" activity are needed to 
attain improved use efficiency of this non-renewable resource.