Use of Compost with Onion (Allium cepa) Waste and Cattle Manure as Substrate Component for Horticultural Seedlings

In the agricultural North-Patagonian region of Argentina, more intensely different alternative substrates of organic origin have begun to be used, which can replace the use of peat to produce vegetable seedlings. The aim of this study was to evaluate the compost obtained from onion waste and cattle manure as a substrate component to produce vegetable seedlings. For a 2- year period (2010-2011), greenhouse trials were conducted. The employed substrates were SCo: commercial substrate, CCE: onion waste compost and cow manure, and M: CCE compost mixture (40%), SCo (40%) + agricultural Perlite (20%). Lettuce (Lactuca sativa L.) was used as an indicator crop. Seeds were sown in germination trays, 128 (1) and 200 (2) cells. The experimental design was completely randomized. Substrates were characterized and measurements of leaf area, fresh weight and dry weight were taken during seedling growth. During both trial years, growth parameters were higher in the seedlings grown in trays with more cells. The seedlings grown in the commercial substrate and compost had the highest leaf area values. The mixture substrates produced the poorest growth, especially when a lower cell volume used. Use of the onion waste compost and cow manure as a substrate component for seedlings replaced the commercial product with satisfactory results, and reduced the use of a poorly available resource like peat.