562 Incorporating Zeolite into Soilless Container Media Reduces Nutrient Leaching in Ornamental Plant Production

Abstract

<jats:p>Containerized ornamental plant production represents extremely intensive agricultural production. An average of 200,000 containers may occupy 1 acre of surface area, to which a large amount of chemical fertilizers will be applied. Because of the use of high-drainage soilless potting mixes coupled with excessive fertigation, a great amount of nutrients, particularly nitrogen and phosphorus, are leached, which increases the potential for ground and surface water contamination. Over the past 2 decades, research has been centered on developing fertigation delivery systems such as nutrient film techniques, ebb-and-flow and capillary mat systems, for reducing leaching. Relatively limited research has been conducted on improving potting medium substrates to minimize nutrient leaching. The objectives of this study were to determine the adsorption isotherm of six different zeolites to ammonium, nitrate and phosphorus, identify and incorporate desired zeolites in a peat/bark-based medium for reducing nutrient leaching in ornamental plant production. Results indicated that the zeolites possess great holding capacities for ammonium, nitrate, and phosphorus. Compared to control, ammonium leaching was reduced 70% to 90%, phosphorus 30% to 80% and nitrate 0% to 60% depending on zeolite species and quantity used per pot. Zeolite amended media caused no adverse effects on plant growth. Conversely, biomass increased significantly when compared to that of the control.</jats:p>

Florida Nursery Best Management Practices: Past, Present, and Future

“…This provides for initially high concentrations of nutrients needed for young transplants, but if the ''imperfectly coated'' amounts are excessive, it could cause too much leaching early in production (Huett, 1997;Million et al, 2007a), even during initial watering in of transplants (Million et al, 2007b). In this regard, some studies have shown that zeolites, gels, and other active compounds can be used as substrate amendments to retain soluble nutrients such as NO 3 -N and orthophosphorus within the container (Broschat, 2001;Chen et al, 2000). Successful research in this area, particularly in regard to NO 3 -N retention, could help buffer against rapid loss of nutrients under these circumstances.…”

Best Management Practices for Minimizing Nitrate Leaching from Container-Grown Nurseries

“…A solution containing a WSF with N at a concentration of 200 mg/L was applied at 100 mL per pot weekly. Results demonstrated that zeolite-amended media leached 30 to 90% less ammonium depending on zeolite species and up to 50% less nitrate than the control media three months after transplanting ( Table 2) [22]. Zeolite amended media had no adverse effects on plant growth, but rather promoted plant growth compared to control media [23].…”