T.O. Ibia  , E.J. Udo  , J.A.I. Omueti  , 
    Fractional Recovery of Applied Phosphorus in Soils of Akwa Ibom State, Niger Delta Region of Nigeria,
    Environmental Research Journal,
    Volume 3,Issue 1,
    2009,
    Pages 1-3,
    ISSN 1994-5396,
    erj.2009.1.3,
    (https://makhillpublications.co/view-article.php?doi=erj.2009.1.3)
    Abstract: Seven surface soil samples, representing the dominant soil parent materials in Akwa Ibom State, Niger Delta Region of Nigeria were treated to various concentration levels of P and the amounts of P measured at time intervals of 1, 10, 50 and 150 days. The phosphorus fixing capacity of the soils increased with increasing rate of added P and time of equilibration. At 1 day, P fixation capacities estimated by fractional recovery varied from 26-66% and at 150 days observation it ranged from 37-76%, respectively for soils of sandstone and beach sands origin. The amount of P required to increase the value of Bray P-1 by 1 mg L<SUP>-1</SUP> (Fertilizer factor) at 150 days ranged from 2.6-5.3 mg L<SUP>-1</SUP> with a corresponding mean of 3.9 mg L<SUP>-1</SUP>. The fertilizer factor appears to provide a useful index of obtaining the P fertilizer needs of the soil, however, calibration and correlation studies in a wide range of soils could further the usefulness of this approach.
    Keywords: Fractional recovery;phosphorus fixing capacity;fertilizer factor;bray P-1