The Effects of AquaSmart-coated Sand Products on Growth and Water Use of Greenhouse-grown Ornamentals and Nutrient Leaching in Greenhouse Media

Water usage is one of the primary continuing costs for new and established greenhouse operations. One way in which growers have been working to reduce water costs is by using wetting agents and hydrophilic polymers. These products help increase the water-holding capacity of the media, and can allow for less frequent irrigation while maintaining desired growth rates. AquaSmart Enterprises, LLC markets a super-absorbent, coated sand product to the greenhouse ornamentals industry. The product should increase water-holding capacity and reduce plant water use in container substrate. The objectives of this study were to evaluate the effects of AquaSmart polymer coated sand products on growth and water use of greenhouse-grown ornamentals and nutrient leaching from greenhouse media. The study was conducted at the Oklahoma State University Research Greenhouse Facility in Stillwater, OK in 2014 and 2015. Six common ornamental species were tested using three application rates of AquaSmart and a nontreated control to compare plant water use and growth rates within species. The nutrient study used the same product application rates, and generated nutrient release curves for each rate.