Evaluation of Zeolite-based Soilless Root Media for Potted Chrysanthemum Production

Abstract

Chrysanthemum growth and nutrient leaching of three clinoptilolite-based root media, which were formulated and provided by Boulder Innovative Technologies, Inc. and ZeoponiX, Inc., were compared to the performance of control plants grown in Sunshine Mix #2 (3 peat: 1 perlite, v/v). The control received 210 mg·L–1 N from an 18N–4P–15K soluble fertilizer at each irrigation. The experimental zeolite-based medium NZ, which contained untreated zeolite and received the same soluble fertilizer as the control, leached lower concentrations of NH4-N, K, and PO4-P for most of the production cycle compared to the control. Medium EZ1 was formulated to provide N, P, and K as fertilizer nutrients and produced plants similar to the control based on ratings, height, width, and dry mass, but not fresh mass, at harvest when the fertilizer rate was half of that applied to the control, 105 mg·L–1 N. Medium EZ2, which did not receive P or K from soluble fertilizer, produced plants similar to the control based on rating, height, and dry mass, but not width or fresh mass, with soluble fertilizer input reduced to only N. Tissue N, P, and K concentrations of plants grown in media EZ1 and EZ2 were lower than those of control plants. With further refinements, these zeolite-based products show promise for decreasing nutrient leaching during crop production and allowing for application of lower rates of soluble fertilizers.