Evaluation of spent biogas silage as casing soil in mushroom cultivation.

Abstract: The effects of casing soil composition on mushroom productivity were studied. The casing soil consisted of: 50% garden loam soil + two-year-old farmyard manure or FYM (control, set 1); spent biogas plant silage + 0.5% diammonium phosphate (DAP)+ 0.5% superphosphate (set 2); 50% spent biogas plant silage + 50% FYM (set 3); 50% spent biogas plant silage + 25% FYM + 25% two-year-old spent compost + 1% DAP + 1% superphosphate (set 4); 50% spent biogas plant silage + 50% spent compost + 0.5% DAP + 0.5% superphosphate (set 5); and 50% spent biogas plant silage + 25% FYM + 25% garden loam soil (set 6). Bags containing the casing soil and a straw-based compost with 1.5-inch thick spawn layer were transferred to growth chambers at 24+or-1 degrees C. The mycelium impregnated the casing soil in 8-10 days. When the casing soil was fully impregnated with mycelia, the temperature of the chamber was lowered to 18+or- degrees C. The mushrooms were harvested after 11-12 days. Except for set 2, which recorded 21% lower crop yi