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United States Department of Agriculture

Agricultural Research Service

Research Project: DEVELOPING BENEFICIAL USES OF AGRICULTURAL, INDUSTRIAL, AND MUNICIPAL BYPRODUCTS

Location: Crop Systems & Global Change

Title: Effects of coal combustion byproduct encapsulated ammonium nitrate on wheat yield and uptake of nitrogen and metals

Author
item Codling, Eton

Submitted to: Coal Combustion and Gasification Products (CCGP)
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 5, 2012
Publication Date: July 31, 2013
Citation: Codling, E.E. 2013. Effects of coal combustion byproduct encapsulated ammonium nitrate on wheat yield and uptake of nitrogen and metals. Coal Combustion and Gasification Products (CCGP). 5:9-15.

Interpretive Summary: Ammonium nitrate is used in agriculture as a nitrogen fertilizer, but it is also an ingredient in explosives. As a result of the bombing of the Alfred P. Murrah Federal Building in Oklahoma City in April 1995, regulations on the sale and shipping of ammonium nitrate have been introduced in the United States. Research is being conducted on reducing the explosiveness of ammonium nitrate by encapsulating it with coal byproducts, such as fly ash and flue gas desulfurization gypsum. The objective of this study was to determine biomass, grain yield, nitrogen and metals uptake by wheat when fertilized with coal byproducts encapsulated with ammonium nitrate. Ammonium nitrate, encapsulated with class C and F fly ash or with flue gas desulfurization-gypsum, as well as unencapsulated ammonium nitrate as a control, were mixed with a low nitrogen soil at rates of 56 and 112 kg ha-1. Hard red spring wheat (Triticum aestivum L.) was grown in the greenhouse and harvested at boot and grain stage. Class C fly ash encapsulated ammonium nitrate significantly increased biomass yield. Grain and straw were significantly higher in the encapsulated treatments at the high rate of application only. Wheat biomass, grain and straw nitrogen concentrations for the plants grown on the encapsulated ammonium nitrate were similar to that of the unencapsulated ammonium nitrate treatment. In this pot study, coal byproduct encapsulated ammonium nitrate fertilizer was as effective as unencapsulated ammonium nitrate for wheat growth, with no significant increase in plant concentrations of arsenic, copper, manganese, or zinc. However, further field studies are needed to verify these findings.

Technical Abstract: Nitrogen is an essential plant nutrient that is taken up in large quantity. Ammonium nitrate (AN) is used in agriculture as an N fertilizer, but it is also an ingredient in explosives. As a result of the bombing of the Alfred P. Murrah Federal Building in Oklahoma City in April 1995, regulations on the sale and shipping of AN have been introduced in the United States. Research is being conducted on reducing the explosiveness of AN by encapsulating it with coal byproducts. The objective of this study was to determine the effects of fertilization with coal byproducts encapsulated with AN on wheat biomass, grain yield, and the uptake of nitrogen and metals by wheat. Ammonium nitrate encapsulated with two forms of coal fly ash (FAC and FAF) or with flue gas desulfurization (FGD)-gypsum, as well as unencapsulated AN as a control, were mixed with a low nitrogen soil at rates of 56 and 112 kg ha-1. Hard red spring wheat (Triticum aestivum L.) was grown in pots in a growth chamber. Biomass yield was significantly increased by the AN+FAC treatment. Yields of grain and straw were significantly higher in the encapsulated treatments at the high rate of application only. Encapsulation of AN did not significantly affect N concentration of wheat biomass, grain, or straw. In this pot study, coal byproduct encapsulated AN fertilizer was as effective as unencapsulated AN for wheat growth, with no significant increase in plant concentrations of As, Cu, Mn, or Zn. However, further field studies are needed to verify these findings.

Last Modified: 12/17/2014