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Resin extraction of labile, soil organic phosphorus
Author(s) -
RUBAEK G. H.,
SIBBESEN E.
Publication year - 1993
Publication title -
journal of soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.244
H-Index - 111
eISSN - 1365-2389
pISSN - 0022-4588
DOI - 10.1111/j.1365-2389.1993.tb00469.x
Subject(s) - extraction (chemistry) , chemistry , chloroform , phosphorus , bicarbonate , ion exchange resin , ion exchange , chloride , soil water , adsorption , soil test , chromatography , environmental chemistry , nuclear chemistry , ion , inorganic chemistry , organic chemistry , soil science , environmental science
SUMMARY In order to develop a method for estimating labile, soil organic phosphorus (P o ), macroporous anion‐exchange and adsorbent (XAD) resins were tested for their ability to extract P o from a permanent pasture soil. Experimental variables included: ionic form, soil‐water resin ratio, addition of cation‐exchange resin, extraction time, extraction temperature, continuous and stepwise extraction and soil pretreatment (chloroform and microwaves). The amounts of extracted P o and P i (inorganic phosphorus) showed little variation between the anion‐exchange resins, when used in the bicarbonate form. In the chloride form, the amounts extracted were less and more variable. XAD resins extracted much less P o and very little P i . The macroporous anion‐exchange resin, Lewatit MP500A in the bicarbonate form, was chosen for further studies. It extracted 21 mg P o kg −1 from air‐dried soil and 8 mg P o kg −1 from moist, incubated soil. The specific amounts of P o and P i extracted were little affected by variations in the ratio between soil, water and resin, but increased with extraction time and temperature. Chloroform pretreatment of the soil mainly increased extracted P i , whereas microwave pretreatment only increased extracted P o . The magnitude of these increases was approximately constant irrespective of extraction temperature, indicating that the increases came from killed micro organisms.