As natural resources dwindle, sustainable alternatives to current fertilization methods are essential for environmental and economic progress. Acid mine drainage (AMD) and phosphorus from fertilizer runoff are significant sources of water pollution in the Appalachian region of the United States. Horticultural producers are faced with rising prices of phosphate fertilizers, putting the industry in a tenuous position: reducing these costly inputs to minimize water pollution but, in turn, diminishing product quality. AMD-based iron-coated sand is a novel phosphate sorbent that can potentially ameliorate AMD and prevent further phosphate pollution. This technology can cut growers’ input costs and slow the consumption of finite phosphate resources. This study aimed to determine the viability of iron-coated sand as a substrate amendment for reducing phosphate leaching and enhancing growth, flowering, and phosphorus uptake of floriculture crops during and after production. The ideal sand-to-potting mix ratio was determined based on pansies, petunias, and chrysanthemums' growth, flowering, and leachate content. The rate of applied phosphate and P-saturation of sand were determined from growth, flowering, and leachate data of chrysanthemum during production. Finally, the effects of the coated sand were examined on petunia and chrysanthemum growth, flowering, mineral content, and leachate composition over time in production and post-production environments. Twenty percent P-saturated iron-coated sand with low to moderate rates of applied phosphorus reduces leached phosphate with no deleterious, and usually positive, effects on the performance of floriculture crops during and after production. Iron-coated sand as a substrate amendment in container production of ornamentals has tremendous potential for advancing environmental and economic sustainability in the horticultural industry.
