were planted in three different composts; horse manure was used as control, maize and grass as synthetic in a complete
randomized design. Nitrogen content of each compost was calculated, moisture content and temperature of the compost were
recorded throughout composting and during conditioning period. Yields of mushrooms were taken in three different flushes.
Results of the mean yields of three mushroom strains grown indicated that the two composts were significantly different; the
grass compost gave significantly superior yields of mushrooms of 549 gm/kg of compost compared to the conventional horse
manure which gave 435.66 gm/ kg of compost. The maize straw synthetic type gave 327.33 gm/ kg of compost (pd”0.05).
Significantly very low yields were realized in the maize straw synthetic type. Though many factors contribute to the yield of
mushrooms, the superiority of the grass synthetic compost may be attributed to three main factors: sufficient nitrogen levels at
spawning, a more open structure that facilitated aeration during composting as well as conditioning, and the high temperature
regime maintained during composting. Maize straw synthetic compost on the other hand remained soggy due to the spongy
stalks which imbibed water readily, especially during steam pasteurization. This resulted in the failure of a temperature build
up. Temperature build -up in phase I as well as at peak heating. Moisture content during composting and aeration of the
compost heap are significant factors in mushroom compost preparation.
