Premium
Corn Growth as Affected by Suspension Fertilizers Containing Fluorosilicic Acid
Author(s) -
Sikora F. J.,
Copeland J P.,
Dillard E. F.,
Burnell J. R.
Publication year - 1992
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/sssaj1992.03615995005600030046x
Subject(s) - chemistry , fertilizer , dry matter , zoology , suspension (topology) , soil water , reagent , phosphate , dry weight , zea mays , agronomy , biochemistry , environmental science , soil science , mathematics , biology , organic chemistry , homotopy , pure mathematics
Fluorosilicic acid (H 2 SiF 6 ) is a suggested additive to suspension fertilizers produced from monoammonium phosphate (MAP) to prevent gelling of the suspension. A greenhouse study was conducted to determine if F added to soil via P suspension fertilizers was detrimental to corn ( Zea mays L.) growth. The F sources consisted of reagent‐grade NH 4 F, NH 4 SiF 6 , and three P suspension fertilizers. Equilibria constants and measurements with a F ‐ ion selective electrode (ISE) indicated SiF 6 2‐ dissociates to H 4 SiO 4 and F ‐ at pH > 4 and total F concentration <1 m M . Therefore, only F ‐ needed to be considered as a potential toxic component in soils. At an initial soil pH of 5.8, an 11% dry‐matter weight decrease was observed when a suspension fertilizer with 89 g F kg −1 was added to soil to supply a rate of 170 mg F kg −1 soil. An adequate level of F in P suspension fertilizers is between 16 and 23 g kg −1 and this level did not affect corn dry‐matter weight with application rates ≤ 32 mg F kg −1 soil. At high soil F‐application rates from 30 to 170 mg F kg −1 soil, F was not suspected to be the phytotoxic agent since F concentrations in corn tops were all <0.4 mg kg −1 . There was a significant correlation between soil Al and F extracted with water, which led to a hypothesis that decreased corn growth was due to Al phytotoxicity.