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Solubility and Cation Exchange in Phosphate Rock and Saturated Clinoptilolite Mixtures
Author(s) -
Allen E. R.,
Hossner L. R.,
Ming D. W.,
Henninger D. L.
Publication year - 1993
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/sssaj1993.03615995005700050034x
Subject(s) - clinoptilolite , solubility , dissolution , chemistry , phosphate , zeolite , ion exchange , phosphorite , cation exchange capacity , soil water , ammonium , inorganic chemistry , nuclear chemistry , ion , geology , organic chemistry , catalysis , soil science
Mixtures of zeolite and phosphate rock (PR) have the potential to provide slow‐release fertilization of plants in synthetic soils by dissolution and ion‐exchange reactions. This study was conducted to examine solubility and cation‐exchange relationships in mixtures of PR and NH 4 ‐ and K‐saturated clinoptilolite (Cp). Batch‐equilibration experiments were designed to investigate the effect of PR source, the proportion of exchangeable K and NH 4 , and the Cp to PR ratio on solution N, P, K, and Ca concentrations. The dissolution and cation‐exchange reactions that occurred after mixing NH 4 ‐ and K‐saturated Cp with PR increased the solubility of the PR and simultaneously released NH 4 and K into solution. The more reactive North Carolina (NC) PR rendered higher solution concentrations of NH 4 and K when mixed with Cp than did Tennessee (TN) PR. Solution P concentrations for the Cp‐NC PR mixture and the Cp‐TN PR mixture were similar. Solution concentrations of N, P, K, and Ca and the ratios of these nutrients in solution varied predictably with the type of PR, the Cp/PR ratio, and the proportions of exchangeable K and NH 4 on the Cp. Our research indicated that slow‐release fertilization using Cp/PR media may provide adequate levels of N, P, and K to support plant growth. Solution Ca concentrations were lower than optimum for plant growth.