Use of MSW compost, dried sewage sludge and other wastes as partial substitutes for peat and soil

The use of different materials; peat, sand or forest soil, in the production of substrates for ornamental plants and for revegetating sealed landfills is a practice leading to economic and environmental problems. Therefore, the feasibility of using composted municipal solid wastes (MSW), sewage sludge and other organic wastes to produce alternative substrates for ornamental plants and to improve the re-vegetation of a closed landfill has been investigated. For substrate production, 50% of the peat content in a common substrate used in Spanish nurseries was successfully replaced with different mixtures of MSW compost, dry sewage sludge, grape marc, rice hull and pine bark, reducing the cost of substrates while not diminishing the quality of plants produced, and using similar amounts of water and nutrients. Regarding re-vegetation of the landfill, the usual 20-40 cm thick layer of fertile soil was successfully replaced with just 5-10 cm of non-fertile soil together with a superficial layer of MSW compost (45 t ha(-1)) or dry sewage sludge (90 t ha(-1)), and bushy authoctonous vegetation was introduced later as usual Good and fast vegetation covering of the landfill was observed after both treatments, which was similar to that obtained with standard and environmentally aggressive revegetating procedures. (C) 1998 Elsevier Science Ltd. All rights reserved.