Growth substrates made from duck excreta enriched wood shavings and source-separated municipal solid waste compost and separates: physical and chemical characteristics

production and use of compost is an effective means to reduce wastes, and o ffers a large potential as growth substrates and source of nutrients. The o bjective of this study was to determine the physical and chemical character istics of duck excreta enriched wood shavings (DMC) and source-separated mu nicipal solid waste (MSW) composts and separates, and to assess the physica l characteristics of growth substrates made from these two composts and sel ected substrates. MSW compost separates were the following sizes: F1 > 4 mm diameter, 2 mm < F2 < 4 mm, 1 mm < F3 < 2 mm and F4 < 1 mm. Growth substra tes were prepared by mixing DMC and F2 and F3 MSW separates (MIM ratios). G rowth substrates A-E consisted exclusively of 10-60% DMC and 20-60% of MSW separates F2 and F3. Growth substrates F-J, and K-O were the same as substr ates A-E, with 15% M/M brick fragments or shredded plastic added as porosit y agents, respectively. Growth substrates (BE/S) made of black earth (BE) a nd sandy loam soil (Ls) in a 1:4 (M/M) ratio, commercially available peat s ubstrate (Pr) and an in-house sphagnum peat-based substrate (Gs) were used for comparison. Principal component analysis (PCA) showed that DMC was a be tter material than MSW with respect to porosity and water field capacity. M SW compost and separates differed by their relatively high levels of water- soluble and HCl-hydrolyzable N and increased advantageous water retention c apacity. PCA also showed that substrates A-E exhibited porosity and water f ield capacity similar to those of Pr. Substrates F-J had porosity and water field capacity similar to those of BE/S, whereas substrates K-O were more similar to Pr and to substrates A and B. The presented data indicate that D MC and MSW separates were complementary in providing good physical and chem ical characteristics to the growth substrates. (C) 2001 Elsevier Science Lt d. All rights reserved.