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Residual Available Phosphorus in Near‐Neutral and Alkaline Soils: II. Persistence and Quantitative Estimation
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/sssaj1982.03615995004600020025x
Subject(s) - soil water , fertilizer , lime , phosphorus , residual , greenhouse , persistence (discontinuity) , environmental science , chemistry , calcareous , agronomy , soil science , mathematics , geology , botany , biology , paleontology , geotechnical engineering , organic chemistry , algorithm
A continuous cropping greenhouse study of 28 Colorado soils with phosphorus (P) rates of 0 and 30 ppm was conducted. The objectives were to (i) evaluate the persistence of residual available P in near‐neutral and calcareous soils and (ii) to predict its quantity. Residual available P was defined as the amount of P removed fron soil by plant uptake until the NaHCO 3 ‐P level dropped to 10 ppm. A residual effect of the fertilizer treatment persisted beyond six greenhouse crops for nearly one‐half of the 28 soils. Recovery of applied fertilizer ranged from 47 to 119% and averaged 74%. The following equation was developed to predict the quantity of residual available P in soils: Residual P, mg/2 kg soil = −17.02 + 2.062 (NaHCO 3 ‐P, ppm) + 0.058 (NaHCO 3 ‐P × clay, %) − 0.187 (lime, % × clay). R 2 = 0.90; 55 soil treatment combinations.