GROWTH OF IMPATIENS ACCENT-RED IN 3 COMPOST PRODUCTS

Growth of Impatiens wallerana Hook.'Accent Red' was evaluated in three composted urban waste materials (composted biosolids and yard trash ( SYT): 20 percent biosolids/sewage sludge, 44 percent yard trimmings, a nd 36 percent mixed paper; composted refuse fuel residues with biosoli ds and yard trash (RYT): 74 percent refuse-derived fuel residuals, 10 percent biosolids/sewage sludge, and 16 percent yard trimmings; and co mposted municipal solid waste (MSW): 100 percent municipal solid waste ). Treatments consisted of 100 percent composted waste and media in wh ich the composted wastes were combined with control medium components at 60 percent, 30 percent, or 0 percent composted waste, by volume. Sh oot dry mass of plants grown in SYT increased as the percentage of SYT in the medium increased, while shoot dry mass of plants grown in MSW linearly decreased from 1.24 g to 0.15 g. There were no significant di fferences in shoot dry mass of plants grown in different percentages o f RYT. Initial medium soluble salt concentrations in MSW media were mo re than double concentrations measured in SYT and RYT media. Soluble s alt concentrations in both the 100 percent and 60 percent MSW media ex ceeded 1.75 dS.m(-1), while the soluble salt concentrations in 100 per cent SYT and 100;percent RYT were 0.50 dS.m(-1) and 0.61 dS.m(-1), res pectively. The C:N ratios in 100 percent SYT and RYT were 17 and 15, r espectively, while 100 percent MSW had a C:N ratio of 29. The relative ly higher level of compost maturity as indicated by lower C:N and solu ble salt concentrations contributed to superior growth of impatiens pl ants in 100 percent SYT and RYT compared to 100 percent MSW.