Zeolite Amendment Reduces Nitrogen and Phosphorus Leaching in Containerized Plant Production

Commercial production of ornamental plants in soilless substrate poses significant risk of nutrient pollution, and development of management practices to reduce N and P leaching is urgently needed. This study aims to determine if zeolite amendment reduces the leaching of nitrate nitrogen (NO3-N), ammonium nitrogen (NH4-N), and phosphorus (P) from soilless substrates incorporated with controlled-release fertilizers (CRFs). Tissue culture liners of a popular ornamental plant, peace lily (Spathiphyllum ‘Viscount’), were transplanted singly into 15-cm plastic pots containing the substrate amended with two zeolites (SC and XY), each at three rates of 10, 20, and 50 g per pot, respectively. Plants were grown in a shaded greenhouse for three months and irrigated at a 0.2 leachate fraction. Collected leachates were analyzed for NH4-N, NO3-N, and P. Results showed that both zeolites reduced N and P leaching with the 50 g per pot rate performing the best. Compared with the control, substrate amended with XY zeolite at 50 g per pot reduced NO3-N leaching by 38.34