Utilization of mixed municipal solid waste compost as a soilless potting component in greenhouse production of four floricultural crops

摘要

Mixed municipal solid waste compost (MSWC) was evaluated as a soilless potting mix component for greenhouse production using four floricultural crops: dusty miller (Senecio cineraria), hybrid petunia (Petunia x hybrida), Japanese holly fern (Cyrtomium folcatum), and begonia (Begonia x semperflorens-cultorum). Dusty miller and petunia plugs were transplanted into 36-cell trays filled with MSWC based substrates and grown for two months. Petunia only grew well in the blend with the lowest MSWC ratio (33%), while dusty miller grew well in all MSWC blends. Japanese holly fern and begonia liners were transplanted into 15 cm (6 in) azalea pots and grown for 12 weeks in five substrates: 100% pine bark (PB), 3:1 PB:MSWC, 1:1 PB:MSWC, 1:3 PB:MSWC, and commercially available Fafard 313 Mix. In addition to substrate, a control led-release fertilizer was applied at two rates to form a two-way factorial completely randomized design. Replacement of PB with MSWC resulted at least equal plant quality and growth of begonia in the aspects of growth index, leaf greenness (SPAD value), flower number, visual rating, and shoot fresh and dry weight. For Japanese holly fern, replacement of PB with MSWC resulted in a lower visual rating, but without other negative responses in plant. For the four greenhouse crops tested, plant growth and quality were seldom negatively affected at low ratios of MSWC (25 to 33%). However, our studies indicate the impact of blending traditional pine bark with higher than 50% MSWC is species specific.