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Partially Acidulated Rock Phosphate as a Source of Phosphorus to Plants: III. Uptake by Corn from Soils of Different Calcium Status
Author(s) -
McLean E. O.,
Balam B. S.
Publication year - 1967
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/sssaj1967.03615995003100060028x
Subject(s) - phosphorite , phosphorus , phosphate , soil water , chemistry , fertilizer , calcium , phosphate fertilizer , agronomy , environmental chemistry , zoology , mineralogy , geology , soil science , biology , biochemistry , organic chemistry
Rock phosphate was treated with H 3 PO 4 to give 5, 10, 50, and 100% acidulations relative to triple superphosphate. The resulting materials were applied to three Ohio soils brought to different calcium levels. The P uptake and the percentage recovery of added P by corn plants ( Zea mays L.) were determined. The soils 1/3‐3/4 Ca saturated generally resulted in better yields, P uptake, and P fertilizer recovery than other Ca saturations. Acidulations beyond 10% in soils less than 1/3 Ca saturated and beyond 50% in soils 1/3‐3/4 Ca saturated were generally not significantly beneficial to P uptake or percentage recovery of added P. Comparison of fertilizers with similar amounts of soluble phosphate but different amounts of insoluble (unreacted) rock phosphate indicated that on the average 1.3 to 1.5 times as much of the added “available” phosphorus was recovered where more insoluble P was present. This was attributed to the reaction of the soil‐formed H 3 PO 4 with unreacted rock phosphate so that less phosphate was fixed by solubilized Al and Fe compounds.