Evaluation of zeolite-based soilless root media for potted chrysanthemum production

Abstract

Chrysanthemum [Dendranthema xgrandiflorum (Ramat.) Kitamura] growth and nutrient leaching of three clinoptilolite-based root media - NZ, EZ1, and EZ2 - 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. NZ contained untreated zeolite and received the same soluble fertilizer as the control but leached lower concentrations of NH4-N, K, and PO4-P during most of the production cycle compared to the control. 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. EZ2 did not receive P or K from soluble fertilizer and 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 N alone. Tissue N, P, and K concentrations of plants grown in 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.