G. Allinson et al., Comparison of behavior of natural and synthetic phosphate fertilizers in moderately water-repellent sandy loam soil under winter rainfall, COMM SOIL S, 31(19-20), 2000, pp. 3027-3035
This study compares the mobility of phosphate-phosphorus (PO4-P) and total
P derived from two commercial phosphate blends, namely a naturally reactive
rock phosphate containing 12.5% P, and an synthetic phosphate containing 9
% P, in small, undisturbed soil cores extracted from a paddock in a daily f
arm approximately 35 km southeast of Warrnambool in the Western Region of V
ictoria, Australia. Since both fertilizers contained major ions, the transp
ort of sodium (Na), potassium (K), calcium (Ca), and magnesium (Mg) were al
so studied. The farm's soil, a water repellent, acid, dark brownish grey, s
and loam is typical of many found in this rich beef and dairy region, and i
s used for pasture. Our results suggest that there was little difference in
chemical dynamics, and by inference chemical bioavailability and ecologica
l safety, between the two commercial phosphate materials.