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Residual Available Phosphorus in Near‐Neutral and Alkaline Soils: I. Solubility and Capacity Relationships
Author(s) -
Fixen P. E.,
Ludwick A. E.
Publication year - 1982
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1982.03615995004600020024x
Subject(s) - solubility , octacalcium phosphate , soil water , phosphate , chemistry , phosphorus , fertilizer , calcareous , environmental chemistry , calcareous soils , agronomy , geology , soil science , organic chemistry , paleontology , biology
A continuous cropping greenhouse study of 28 Colorado soils with phosphorus (P) rates of 0 and 30 ppm was conducted. The objective was to investigate the nature and solubility of residual available P in near‐neutral and calcareous soils. Solubility and capacity factor comparisons indicate that octacalcium phosphate was not likely an important residue in 27 of the 28 soils. One of the soils which had a history of heavy barnyard manure applications appeared to be buffered in the vicinity of the octacalcium phosphate isotherm. Tricalcium phosphate or a mineral similar in composition and solubility may have accounted for at least a portion of the fertilizer residues. The plant availability of tricalcium phosphate is apparently quite low since seven of the nine calcareous soils initially plotting on or near this isotherm responded to P fertilization.