Phosphorus organic input

This is the principal linkage between cyanobacterial blooms and eutrophication. Avoidance of cyanobacterial production does not necessarily depend upon eliminating all phosphorus inputs, but upon ensuring that optimum physical and chemical conditions for these organisms do not coincide. It is easy to understand why the biggest blooms in the UK have been in fertile lakes and reservoirs after prolonged spells of warm, dry weather in summer. 

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... 

Potential processes that may be called upon to explain the large discrepancy between excess N2 and NOs deficits within the SNM are (1) sedimentary denitrification, (2) anammox, (3) metal (Fe, Mn)-catalyzed denitrification, and (4) non-Redfieldian organic matter mineralization (Codispoti et al., 2001 Devol et al., 2006a,b). The first of these possibilities requires a decoupling between nitrogen and phosphorus cycles (e.g. possible greater burial of phosphorus in continental margin sediments). The less likely additional requirement is that the maximal inputs from the sediments should occur at the same depth as the water column peak of N02. In other words, the exact coincidence of the extrema in NOs , N02, ... 

Mutualistic species interactions contribute directly to many essential ecosystem processes, such as nutrient inputs through nitrogen fixation and mycorrhizal associations that govern phosphorus and organic nitrogen uptake by plants (Read, 1991). Other mutualisms, such as pollination and seed dispersal, have indirect effects, influencing the presence or absence of species that may have strong ecosystem effects. 

Organic P also occurs in dissolved forms, particularly in euphoric surface waters, where it may exceed inorganic phosphate concentrations (Smith et al., 1986). The labile fraction of dissolved organic phosphorus may be the most rapidly cycled marine phosphate pool (Orrett and Karl, 1987 Jackson and Williams, 1985). This pool may also provide a "buffer", providing utilizable phosphate to phytoplankton between episodic inputs from other sources (Jackson and Williams, 1985). 

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