Phosphorus mineralization

Dobolyi and Bidlo [76] determined the phosphorus-containing minerals in Balatien lake sediment, and thus the forms in which the phosphorus responsible for the accelerating eutrophication of the lake are present. Samples were subjected to chemical, electron microscope and X-ray analysis. Hydroxylapatite was identified, but no proof of the presence of other phosphorus minerals was obtained. 

Fermentations may be aerobic when the cells must be in the presence of an O2 environment or anaerobic when they cannot. Water is the standard fermentation medium and is also one of the products, as is carbon dioxide, which is removed from the liquid and leaves in a vapor product stream since it may have a negative effect on the cells. Other nutrients or media (sources of nitrogen, phosphorus, minerals, vitamins, etc.) typically must be supplied to keep the organisms happy and healthy. 

Wetzel, R.G. (1999) Organic phosphorus mineralization in soils and sediments. In Phosphorus Biogeochemistry of Subtropical Ecosystems (Reddy, K.R., O Connor, GA., and Schelske, C.L., eds.), pp. 225-245, CRC Press, Boca Raton, FL. 

Occurrence and Circulation op Phosphorus —-Mineral Phosphates—Assimilation by Plants—Sources of Phosphates—The Composition of Phosphorites —-The Distribution of Phosphatic Rooks—Ooeanio Deposits and Guanos—-The World s Production of Phosphate Rook. 

During high discharge, many areas of the Genesee basin are subsaturated with respect to calclte, while during summer baseflow periods calcite saturation or supersaturation is widespread. Under these conditions calcite could mediate phosphorus mineral formation. 

A detailed examination of phosphate distribution between solution and solid phase during calcite crystallization in a simulated natural water shows that phosphorus adsorbs as a mono-layer, causing slight changes in the solution phosphorus concentration. It appears that under the conditions examined in this study, calcite- mediated phosphorus mineralization has a role in the movement of phosphorus from the water column to bed sediments, although the extent and rates of the process in natural systems remain to be determined. 

Reaction of phosphate with calcite surfaces appears likely in hard water areas, but low adsorption capacity and slow kinetics of the phosphate-calcite reaction under natural conditions probably prevent calcite mediated phosphorus mineralization from becoming a greater phosphorus sink than binding to the amorphous iron oxides. 

Mafongoya P., Barak P., and Reed J. (2000) Carbon, nitrogen, and phosphorus mineralization of tree leaves and manure. Biol. Fertil. Soils 30, 298—305. 

Olayinka, A., and Babalola, G. O. (2001). Effects of copper sulphate application on microbial numbers and respiration, nitrifier and urease activities, and nitrogen and phosphorus mineralization in an alfisol. Biol. Agric. Hortic. 19, 1-8. 

The term d[P j,]/dt is calculated assuming that the concentration of phosphorus in all decomposing litter is 0.16 mmol 1110 . This is based on the 68% retranslocation of P from leaves and fine roots and the average branch, bole, and coarse root P concentrations (Sec. 3.2). Where the sensitivity of the model to P accumulation in the microbial carbon pool is tested, based on data summarized by Gijsman et al. (1996) we use a tissue P concentration for microbes of 6.4 mmol P moG C. In all simulations, it is assumed that soil phosphorus mineralization proceeds with a rate constant of 0.5 year , with phosphorus mineralization proceeding independently of carbon mineralization. This is on the basis of the evidence discussed in Sec. 2.1. Indeed, inflexible soil carbon pool C/P ratios which effectively link phosphorus mineralization rate to the carbon mineralization rate in models such as CENTURY (Parton et al, 1988) have been strongly criticized by some tropical soil chemists (Gijsman et al, 1996). 

Both an automatic peak-picking routine in the processing software and visual inspection are used to identify peaks. Chemical shifts are then compared with literature reports. Table 2.1 shows some of the biological phosphorus compounds identihed in NMR studies of environmental samples, while Table 2.2 shows peak shifts for phosphorus minerals determined by solid-state spectroscopy. Although this chapter focuses on organic phosphorus, the overlap of peak shifts for biological and mineral phosphorus compounds must be noted. This may complicate the identification of phosphorus species in solid-state spectroscopy, because both biological and mineral phosphorus forms may be present. To further confirm peak shifts, standards such as methylene diphosphonic acid may be added directly to the sample or included as capillary tube inserts in solution NMR (e.g. Koopmans et aL, 2003). 

R. L. and Wollum, A.G. (2002) Monitoring phosphorus mineralization from poultry manure using phosphatase assays and phosphorus-31 nuclear magnetic resonance spectroscopy. Communications in Soil Science and Plant Analysis 33, 1205-1217. 

The mineralization of microbial phosphorus is treated in detail above, and organic phosphorus mineralization is also addressed elsewhere in this volume (Nziguheba and Biinemann, Chapter 11 Condron and Tiessen, Chapter 13). Therefore, we focus here on some quantitative aspects of soil organic phosphorus mineralization and summarize studies where the role of microorganisms in the decomposition of organic amendments was studied in detail. 

Microbial phosphorus turnover also takes place in the absence of net changes in the microbial biomass. Isotope studies suggest that related phosphorus fluxes are important, but the underlying processes in soils are not well understood. Studies should test whether diffusion and efflux from microbial cells are important. Models would help to integrate different processes and factors related to gross phosphorus mineralization and microbial phosphorus turnover in general. 

Cressel, N. and McColl, J.C. (1 997) Phosphorus mineralization and organic matter decomposition a critical review. In Cadisch, C. and Ciller, K.E. (eds) Driven by Nature Plant Litter Quality and Decomposition. CAB International, Wallingford, UK, pp. 297-309. 

Joseph, P., George, M., Wahid, P.A., John, P.S. and Kamalm, N.V. (1995) Dynamics of phosphorus mineralization from P-labelled green manure. Journal of Nuclear Agriculture and Biology 24, 158-162. 

Oehl, F., Oberson, A., Sinaj, S. and Frossard, E. (2001a) Organic phosphorus mineralization studies using isotopic dilution techniques. Soil Science Society of America Journal 55, 780-787. 

Oehl, F., Frossard, E., Fliessbach, A., Dubois, D. and Oberson, A. (2004) Basal organic phosphorus mineralization in soils under different farming systems. Soil Biology and Biochemistry 36, 667-675. 

Walbridge, M.R. and Vitousek, P.M. (1 987) Phosphorus mineralization potentials in acid organic soils processes affecting PO,p isotope dilution measurements. Soil Biology and Biochemistry 1 9, 709-71 7. 

Zou, X., Binkley, D. and Doxtader, K.G. (1992) A new method for estimating gross phosphorus mineralization and immobilization rates in soils. Plant and Soil 47, 243-250. 

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