EVALUATION OF ORGANIC SOLID WASTES COMPOSTS AS PEAT SUBSTITUTES FOR SEEDLING PRODUCTION

Abstract

This research work was performed to investigate the possibility of using composted herb residues (C1), co-composted sewage sludge with sawdust (C2), co-composted pig manure with sawdust (C3), and co-composted pig manure with spent mushroom (C4) in the production of horticultural seedlings to replace part of peat in the growing media. The proportions of each compost in the mixtures elaborated with peat were 50%, 75%, and 100% (v/v), respectively. The substrate of 100% commercial peat was used as the control. First, some physical, physical-chemical, and chemical properties of these substrates were determined. Second, four kinds of plants tomato, cucumber, bermudagrass, and impatiens were used to evaluate the possibility of different composts to replace part of peat. The seed germination rate, fresh weight and nutrient concentrations of seedling were then measured. We found that the physical, physical-chemical and chemical properties of these substrates were statistically influenced by the type and the proportion of compost in the substrates. The substrates elaborated with C1 and C2 showed adequate physical and chemical properties for their use as substrate in horticultural seedlings production. The highest germination of cucumber, tomato, bermudagrass and impatiens all occurred at C1 based substrate. Seedling grown in the C1 and C2 based substrate reached better growth and nutrition than peat. Our results suggested that the C1 and C2 were good alternative to peat-based substrate for seedling production, especially at the rate of 75% and 100% of C1 and 50% of C2, which have shown beneficial effects on the seedling production of cucumber, tomato, bermudagrass and impatiens compared to the control. However, C3 and C4 were not always adequately used in substituting expensive peat.

Keywords:

• organic solid wastes
• composts
• peat substitutes
• substrates
• seedling production

ACKNOWLEDGMENTS

This research was financially supported by the National Natural Science Foundation of China (No. 40871101, No. 51008107), and the Provincial Technique Program of Zhejiang (No. 2010C33159).