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FEASIBILITY OF USING IRON AND ALUMINUM PHOSPHATES AS PHOSPHATIC FERTILIZER SOURCES ON CALCAREOUS SOILS
Abstract
Thermodynamic criteria demonstrate Al- and Fe-phosphate solubilities increase as pH increases. Therefore, application of these fertilizer materials to calcareous soils may produce and maintain greater P availability over time compared to a Ca-phosphate fertilizer material. The objectives of this research were to: (i) investigate the fate of applied Al-, Fe-, and Ca-phosphates with respect to plant available P in some calcareous soils (Ustic Torriorthent and Aridic Argiustroll) over time and (ii) to determine how Al-, Fe-, and Ca-phosphates compared as P-fertilizer sources for Oslo spring wheat (Triticum aestivum L.) grown on a calcareous soil (Typic Haplustoll). Soil incubation and greenhouse experiments were conducted using Ca(H(,2)PO(,4))(,2)(.)H(,2)O, FePO(,4)(.)2H(,2)O, and AlPO(,4) at equivalent P concentrations. Soil was incubated for 60 weeks under controlled conditions, air-dried, and subsamples taken for NaHCO(,3)-extractable P, organic P, and P-fractionation analysis. NaHCO(,3)-extractable P levels increased in the calcareous soils over the 60 weeks for the AlP and FeP-fertilizer sources whereas the CaP-fertilizer source decreased in NaHCO(,3)-extractable P. An acid soil treated with FeP and CaP-fertilizer sources decreased in acid-fluoride extractable P over a 16 week incubations and the AlP-fertilizer source remained relatively constant over the 16 week incubation. Three sequential croppings of spring wheat in the greenhouse showed greater plant response to both the FeP and AlP-fertilizer materials compared to CaP-fertilizer material after crop 1. When organic P levels in both experiments increased or decreased there was a corresponding change in the NaHCO(,3)-extractable P levels and plant response in both the controls and P-treated soil. Water solubility of the P-fertilizer source appeared to determine the extent of hydrolysis and therefore, the amount of P in the soil solution.
Subject Area
Agricultural chemicals|Agronomy
Recommended Citation
SUTTON, PAMELA JEAN, "FEASIBILITY OF USING IRON AND ALUMINUM PHOSPHATES AS PHOSPHATIC FERTILIZER SOURCES ON CALCAREOUS SOILS" (1985). ETD collection for University of Nebraska-Lincoln. AAI8526604.
https://digitalcommons.unl.edu/dissertations/AAI8526604