The major ingredients in mushroom growing
are typically recycled agricultural waste products and other materials which include hay, straw, horse bedding,
poultry litter, corn cobs, corn stover, cotton seed meal, cocoa hulls in various amounts and proportions.(Chang
and Miles [5];Stamets [6]. After a cropping cycle has been completed and the substrate has been depleted of
nutrients needed for growing mushrooms, the substrate is removed from the production facility and discarded.
SMS is the soil-like material remaining after a crop of mushrooms. Spent substrate is high in organic matter
consisting of decomposed plant, animal and fungal residues and materials making it desirable for use as a soil
amendment or soil conditioner even in land reclamation Rupert [7]; Davis et al [8]; Lemaire et al[9]; Lohr et al
[10]; Rinker [3];Wang et al.[11];Wuest et al[12]). In a report by Rinker [3], used mushroom growing substrates
are far from spent and can be put to various other uses. Spent substrate is the choice ingredient by those
companies making the potting mixtures sold in supermarkets or garden centers. Most of the needed ingredients for
chicken feed are not locally available and have to be imported according to Shaiful [13].