Studies on recycling spent compost for mushroom cultivation

Abstract

Natural weathering of spent compost for 2 years resulted in a lowering of electrical conductivity which enabled it to be used as a casing material in mushroom cultivation. Spent compost and peat moss had different optima of electrical conductivity values for normal mushroom production. Relatively high levels of soluble salts such as calcium nitrate and calcium chloride reduced the yield of mushrooms. The addition of rice hulls and peat moss to spent compost overcame the effect of sealing caused by watering. These amendments improved aeration of the casing layer and increased the number of pseudomonads. Pasteurized, spent compost, aged for 2 years, at a moisture level of 65% saturation, was shown to be a suitable casing material for obtaining relatively good yields of mushrooms. It is suggested that this material may find an application in commercial cultivation of mushrooms.