ISSN:
1573-0867
Keywords:
Soil
;
fused phosphate
;
incubation
;
dissolution
;
P fractions
;
P level
;
P transformation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract The dissolution of fused calcium phosphate (FP) and transformation of P were monitored in a silt loam, sandy loam, sandy clay and clay soil (pH in water = 5.3 − 5.8) incubated with 0, 108 or 324 mg P, as FP kg−1 soil dry wt, for 10, 30 or 60 d. Soluble P was fractionated by sequential extraction using a chloride anion exchanger (P-resin) and solutions of NaHCO3 (PtCO3), NaOH (PtOH) and HCl (P-HCl). Inorganic P (PiCO3, PiOH) and organic P (PoCO3, PoOH) were also determined. The FP treatments significantly (P = 5%) increased both P-resin and P-HCl levels. Over time, the differences between P-resin or P-HCl levels and the controls declined, except in the silt loam soil in which P-resin levels nearly doubled. PtCO3 and PtOH levels did not markedly respond to FP applications. As incubation proceeded PtOH levels significantly (P = 5%) increased both as PiOH and PoOH. This PtOH buildup was accompanied by small declines in PtCO3 levels, with the declines being greater in the PoCO3 than in PiCO3 fraction. P-resin, PiOH and PoOH levels were negatively correlated with those of p-HCl (P = 5%, n = 36). P-resin levels were also negatively correlated with those of PoCO3. Of the small and large FP doses, 12–45% and 51–56%, respectively, had yet to react by the end of the experiment.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01048957
