Phosphorus availability

Paulsson M, Mansson V, Blanck H (2002) Effects of zinc on the phosphorus availability to periphyton communities from the river Gota Alv. Aquat Toxicol 56 103... 

G. Schilling, A. Gransee, A. Deubel, G. Lczovic, and S. Ruppel, Phosphorus avail-... 

G. A. Gilbert, C. P. Vance, and D. L. Allan. Regulation of white lupin root metabolism by phosphorus availability. Phosphorus in Plant Biology Regulatory Roles in Molecular. Cellular, Organismlc, and Ecosystem Processes (J. P. Lynch and J. Deikman. eds,), American Society of Plant Physiologists, 1998, p. 157. 

H Keith, R. J. Raison, and K. L. Jacobson, Allocation of carbon in a mature eucalypt forest and some effects of soil phosphorus availability. Plant Soil 796 81 (1997). 

The reaction is performed most simply by the addition of the propargylic alcohol to a solution of the phosphorus halide. Rearrangement of the phosphorus ester proceeds at ambient temperature or with mild heating. When phosphorus trihalides are used, the product can be isolated as the phosphonic dichloride.168169 Aqueous workup provides the phosphonic acid.162 In most instances, however, a dialkyl phosphorochloridite with only a single halogen on phosphorus available for reaction with alcohol has been used.165 170 174... 

Oehl F, Oberson A, Tagmann HU, Besson JM, Dubois D, Mader P, Roth HR, Frossard E (2002) Phosphorus budget and phosphorus availability in soils under organic and conventional farming. Nutr Cycl Agroecosyst 62 25-35... 

Kwabiah AB, Stoskopf NC, Palm CA, Voroney RP, Rao MR, Gacheru E (2003) Phosphorus availability and maize response to organic and inorganic fertilizer inputs in a short term study in western Kenya. Agric Ecosyst Environ 95 49-59... 

Bucher S. 2001. Nitrogen and phosphorus availability in irrigated rice as influenced by soil drying during the fallow period, straw incorporation, and tillage. PhD thesis, ETH-Zilrich. 

A dietary deficiency of phosphorus is unlikely, as this mineral occurs in nearly all foods and many food additives (NAS 1980A Greger and Krystofiak 1982). Foods in the milk group, for example, contribute 35.8% of the phosphorus available for civilian consumption (Table 7.1). Adults generally consume about twice as much phosphorus as the RDA of 800 mg (NAS 1980A Greger and Krystofiak 1982). 

The amount of phosphorus excreted in the urine vanes with the level of ingested phosphorus and factors influencing phosphorus availability and utilization. It has been shown that in the dog, when plasma phosphate is normal or low, over 99% of the filtered ion is reabsorbed, presumably in die upper part of the proximal tubule. Increased plasma concentrations of alanine, glycine, and glucose depress phosphate reabsorption. 

When phosphorus fertilizers are added to soils deficient in available forms of the element, increased crop and pasture yields ordinarily follow. Sometimes the phosphorus concentration in the crop is increased, and this increase may help to prevent phosphorus deficiency in the animals consuming the crop, but this is not always so. Some soils convert phosphorus added in fertilizers to forms that are not available to plants. On these soils, very heavy applications of phosphorus fertilizer may be required. Some plants always contain low concentrations of phosphorus even though phosphorus availability from the soil may be good. See also Fertilizer. 

Z. Yi, E. T. Kornegay, V. Ravindran, and D. M. Denbow, Improving phytate phosphorus availability in corn and soybean meal for broilers using microbial phytase and calculation of phosphorus equivalency values for phytase, Poultry Sci. 1996c, 75, 240-249. 

Pietras et al. 1968 Rao and Brown 1974 Rubitsky and Myerson 1949 Simon and Pickering 1976 Wechsler and Wechsler 1951) and several occupational exposure studies (Heimann 1946 Hughes et al. 1962 Kennon and Hallam 1944 Legge 1920 Ward 1928). Because most individuals vomited shortly after ingestion of white phosphorus, the amount of white phosphorus available for absorption is not known. In the occupational exposure studies, the concentration of airborne white phosphorus was not reported. White phosphorus is still used in the munitions industry and further studies of these workers may yield more useful information on dose-response relationships and provide quantifiable data that could be used to monitor individuals living near hazardous waste sites. 

Stirling, H.P., and Wormald, A.P. (1977) Phosphate/sediment interaction in toto and Long Elarbors, Elong Kong, and its role in estuarine phosphorus availability. Estuar. Coastal Shelf Sci. 5, 631-642. 

Several studies have examined unconcentrated bulk water using a tracer approach. Goering et al. (1966) first reported on unconcentrated, bulk water uptake studies off the northeast coast of South America. Their results could account for rates of about 86 and 271 pmol N2 m day for 2 observations and 9 observations in the fall of 1966 and spring of 1967, respectively. They reported appreciable Trichodesmium in most of their samples. Voss et al. (2004) recendy found relatively high rates on the eastern side of the basin off NW Africa, with somewhat lower rates on the western boundary, and activity was below detection Emits in the central portion of the basin (Tables 4.4 and 4.5). Rees et al. (2006) observed very high rates of N2 fixation in the eastern Mediterranean which were apparently limited by phosphorus availability (Table 4.4). 

A proper balance of nutrients is required for plant growth. In marine systems, the stoichiometry of primary production is determined by the ratio of elements in the cytoplasm (Redfield ratio) that supports optimal metabolism of phytoplankton (Redfield, 1958). The C N P ratio is fairly constant in marine phytoplankton, and this ratio in primary producers constrains the cycling of aU elements (Elser et al., 2000). The amount and proportions of nitrogen and phosphorus available determine the amount of carbon fixed by phytoplankton. Limitation by either of these... 

Lajtha K. and Schlesinger W. H. (1988) The biogeochemistry of phosphorus cycling and phosphorus availability along a desert soil chronosequence. Ecology 69, 24-39. 

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