Greenhouse evaluation of controlled-release iron fertilizers for soybean

• Published in: Journal of plant nutrition 2004-01, Vol.27 (1), p.43-55
• Main Authors: Goos, R.J, Johnson, B, Jackson, G, Hargrove, G
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Chelates; DTPA; Economic plant physiology; EDDHA; Ferrous sulfate; Fundamental and applied biological sciences. Psychology; Glycine max; Iron deficiency chlorosis; Metabolism; Metabolism. Physicochemical requirements; Nutrition. Photosynthesis. Respiration. Metabolism; Plant physiology and development; Slow-release fertilizers; Soybean
• ISSN: 0190-4167; 1532-4087
• DOI: 10.1081/PLN-120027546

Iron (Fe) deficiency chlorosis is a widespread problem for soybean Glycine max L. (Merr.) production in the North Central region of the United States. Fertilization options are limited due to the high cost of soil-applied chelates, and inconsistent crop response to foliar sprays. The objective of this study was to evaluate the response of soybean to several inorganic and organic Fe sources applied alone or coated with Polyon organic polymers. Three greenhouse experiments were performed, using an alkaline Ulen sandy loam soil. Chlorosis was severe in all three experiments. Most of the products tested, such as uncoated ferrous sulfate, polymer-coated ferrous sulfate, or polymer-coated urea-ferrous sulfate, gave small increases in leaf chlorophyll content at the unifoliate or first trifoliolate stage, but not at the second or third trifoliolate stages. The most dramatic increases in leaf chlorophyll content and dry matter production were observed when the soil was amended with uncoated FeEDDHA or with a polymer-coated mixture of ferrous sulfate, ammonium sulfate, and citric acid. It was concluded that polymer-coated ferrous sulfate-ammonium sulfate-citric acid deserves further evaluation.