Evaluation of Different Casing Soils on Quantitative and Qualitative Characteristics of Button Mushroom (Agaricus bisporus L.)

Casing material or soil (casing) is used in mushroom (Agaricus bisporus) culture to cover a nutritional composted substrate colonised with mycelium, and has an essential function in stimulating and promoting the development of sporophores (fruit bodies). In order to use the agricultural by products (different wastes) to reduce peat consumption of casing soil in button mushroom production, an experiment was conducted in 2010 with treatments of casing soil and three replicates in a completely randomized design. Treatments consist of: 1- decomposed manure and loam soil (50%, 50%), 2- decomposed manure, spent mushroom compost and loam soil (25%, 45%, 30%), 3- decomposed manure, 4- moderate loam soil, 5- bagasse and loam soil (50%, 50%), 6- spent mushroom compost and sand (60%, 40%), 7- loam soil and sand (70%, 30%), 8- rice waste and loam soil (40%, 60%),9- cocopeat and perlit (60%, 40%),10- tea waste and loam soil (50%, 50%), 11- Holland peat, 12- north peat, 13- south peat, 14- spent mushroom compost and north peat (60%, 40%),15- spent mushroom compost, 16- clay soil and north peat (65%, 35%), and 17- clay soil and sand (65%, 35%). A comparison of means with Duncan's Multiple Range Test (DNMRT) indicated that in Holland peat and north peat, mycelium could cover soil in shortest time compared to the other treatments. Results indicated that treatment of spent mushroom compost + north peat (40%, 60%) produced highest yield (2093 kg) after Holland peat. In addition, in this treatment, harvested mushroom had the highest protein content compared to other treatments. The lowest yield was obtained in loam soil + sand (70%, 30%) due to an final decrease of casing soil porosity and Water Holding Capacity. Therefore, spent mushroom compost is an alternative to reduce peat consumption in button mushroom production.