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Phosphate availability indices related to phosphate fractions in selected malawi soils
Author(s) -
Maida James H. A.
Publication year - 1978
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740290503
Subject(s) - phosphate , fractionation , chemistry , soil water , zoology , extraction (chemistry) , ion exchange resin , acetic acid , fraction (chemistry) , environmental chemistry , nuclear chemistry , mineralogy , chromatography , geology , biochemistry , biology , organic chemistry , soil science
The amounts of soil P extracted by the methods of Olsen P, Bray‐P 1 , Williams and Stewart, Morgan, Aslyng, anion exchange resin, Saunder, Dyer, and North Carolina were significantly interrelated. P fractionation studies indicated that a relatively high proportion of the inorganic P was accounted for by iron‐bound and reductant‐soluble P fractions. The most important variable contributing to the total variation in the regressions of equilibrium phosphate potential and Morgan‐P values was the saloid‐bound P fraction. Al‐P was the major source of variation in Dyer‐P, North Carolina P, Olsen‐P, Bray‐P 1 , resin extractable P, and acetic acid soluble P values. The extraction of Al‐P by the chemical soil tests was in the decreasing order of Dyer‐P > North Carolina P>0.1M‐NaOH‐extractable P>0.5m‐CH 3 COOH > Olsen‐P >Bray‐P 1 anion exchange resin. Fe‐P was the second most important variable contributing to the total variation in 0.1M‐NaOH extractable P, Olsen‐P, North Carolina P, resin extractable P and Dyer‐P values. Practical implications of the findings were discussed.