Effects of ammonium nitrate encapsulated with coal combustion byproducts on nutrient accumulation by corn and rye

ABSTRACT

Ammonium nitrate is a fertilizer and an explosive. Encapsulation of ammonium nitrate (NH₄NO₃) with coal combustion byproducts (fly ash or flue gas desulfurization gypsum) reduces the explosiveness of NH₄NO₃. A field study was conducted to determine the effects of encapsulated NH₄NO₃ on corn (Zea mays L.) and rye (Secale cereal L.) yield and accumulation of nitrogen (N), arsenic (As), cadmium (Cd), iron (Pb), copper (Cu), manganese (Mn), and zinc (Zn). Nitrogen rates were 56 and 112 kg ha⁻¹. Yields and concentrations of N and metals in corn grain, ear-leaf, and stover and in rye shoots were not affected by N source. Increased N rate resulted in increased corn ear-leaf, grain, and stover N, ear-leaf Cu, Mn, and Zn, and rye shoot yield, Cu, and Zn. For both species, metal levels did not exceed normal ranges. Coal byproduct-encapsulated NH₄NO₃ is as effective as non-encapsulated NH₄NO₃ for corn or rye production, without increasing plant metal concentrations above normal levels.

KEYWORDS:

• power plant
• coal
• combustion byproducts
• safer fertilizer
• ammonium nitrate
• encapsulation

Acknowledgments

The author thanks Dr. Darrell Taulbee for providing the encapsulated ammonium nitrate for this study, Mr. George Meyers for preparing the field and planting the crops, and Mrs. Mebrat Gesese for her assistance in analyzing soil and plant samples.

Abbreviations

FGDG	=	flue gas desulfurization gypsum
FAC	=	class C fly ash