EFFECT OF ORGANIC ANIONS AND SUGARS ON PHOSPHATE PRECIPITATION BY IRON AND ALUMINUM AS INFLUENCED BY pH

Retention of Ortho- And Polyphosphates in Some Quebec Soils as Affected by Added Organic Residues and Calcium Carbonate

“…It is interesting to note that increased extractable P with added alfalfa was approximately equal to the 0.5 N H2SO4 extractable P in the alfalfa residue (Table l0) (Nagarajah et al. 1970) or by forming organometallic complexes with Fe and Al (Bradley and Sieling 1953;Struthers and Sieling 1950). Organic P forms such as inositol phosphates could also have contributed to the observed reduction in P retention.…”

Aluminium polyphosphate in the ectomycorrhizal fungus Suillus variegatus (Fr.) O. Kunze as revealed by energy dispersive spectrometry

“…Ectomycorrhizal fungi synthesize oxalic acid (Lapeyrie, Chilvers & Bhem, 1987), which is able to chelate Al to a non-toxic form in growth media like other organic acids (Jones, 1961;Sivasubramaniam & Talibudeen, 1971;Rajan et al, 1981). Many sugars such as glucose, fructose, galactose, maltose, arabinose and rhamnose, produced and secreted by roots and microbes into their growth media, form metallo-organic complexes with Al (Bradley & Sieling, 1953).…”

Forest regeneration at northern latitudes close to timber line. Proceedings, 7th annual workshop on silviculture and management of northern forests: 1985 June 16-20; Lulea, Gallivare, and Ostersund, Sweden.

“…apatite phosphorus, and the phosphates of iron, aluminium, magnesium and manganese are subject to this action of micro-organisms (Alexander 1977, Amberger 1979. Many micro-organisms require organic substances to enable this solubilization to take place, and are then capable of decomposing carbohydrates in the soil and releasing sugars and organic acids (Dalton et ale 1952, Bradley & Sieling 1953. Many of the sugars_ e.g.…”

“…The binding of phosphorus to metals and to the acidifying ground-layer vegetation, principally Calluna, may cause a disturbance in the phosphorus balance of the pine saplings in ploughed areas. The increased solubility of metals does not restrict the growth of the ling itself, however, since this species is efficient in its uptake of phosphorus and presumably continues to obtain it in adequate amounts, in addition to which it has been shown to bind at least aluminium, copper and zinc from the soil by virtue of its mycorrhizal action, thereby protecting the growing shoot from the toxic effect of such metals (Bradley et al 1981,1982, Read 1983. Acidification of the soil may also be one reason for the invasion of ploughed forest areas by Deschampsia flexuosa, which according to Hackett (1964) will tolerate a low pH and high aluminium content in the soil.…”