Compost mixes as substrates for seedling production

• Autor(a) principal: Reis, Mário
• Data de Publicação: 2007
• Outros Autores: Coelho, Luísa
• Tipo de documento: Livro
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.1/20334
• topic: Sewage sludge; Municipal solid waste; Yard prunings; Lycopersicon esculentum Mill. L.; Capsicum annuum L.; Brassica oleracea L.

Composts were mixed with peat, to prepare substrates for the production of vegetable seedlings. Sewage sludge, municipal solid waste and yard prunings, were mixed in the proportions (v/v) of 1:0:3 (compost A); 0:1:1.5 (compost B) and 1:1:2 (compost C) and composted in windrows. Composts were sieved (<4mm) and mixed with a commercial peat mix for nurseries (Pindstrup Plus, Pindstrup Rosebrug A/S, Denmark) in percentages ranging from 20 to 60% (v/v). Prepared mixes were used in polystyrene seedling trays of 15 and 18 cm3 (242 and 338 plants per tray). The incorporation of physical soil conditioner with hydroabsorbent polymers (Terracottem®, Belgium, 5 gL-1) in the substrate was also tested. Composts and their mixes were chemically and physically characterised. Tested vegetable species were: Lycopersicon esculentum Mill. L., Capsicum annuum L. and Brassica oleracea L. Trials were conducted in a commercial nursery (Viveiros Vida Verde, Faro, Portugal), during 2002 and 2003, in a greenhouse with automatic (micro sprinklers) and manual irrigation. Tested composts showed no remarkable differences among them and were able to replace peat in mixes for seedling trays up to 60% (v/v) on cabbage and 40% with tomato and pepper, sometimes with increased plant growth. However, the extraction of plants from the seedling trays may become more difficult. In some growing mixes, hydrogel increased seedling growth. On tomato, the emergence of seedlings was not affected or it was reduced in compost mixes. When seed emergence was reduced, an increase in the number of days to achieve commercial size seedlings was observed. Hydrogel increased plant growth on commercial peat mix and on 30% compost mixes, but not on 20% mixes. Pepper seedlings emergence was not affected and plant growth was increased with compost, both 20 and 40%. Hydrogel increased plant growth on 20% compost mixes, but not on 40% mixes. Cabbage seeds germination was reduced on 60% compost mixes, but seedlings growth was increased. Hidrogel increased only some growth variables.