Abstract:
Edible mushroom cultivation is a profitable cottage industry, in which oyster mushroom occu
pies a prominent place in Sri Lanka. A good substrate is a key factor that determines the prof
itability of the mushroom cultivation. The Department of Agriculture recommends soya flour
as a nitrogen supplement for mushroom substrate. Nonetheless production cost could be mini
mized if cheaper nitrogen sources could replace the traditional ingredients. Therefore the rela
tive efficacy of six compost mixtures, each amended with one of the following nitrogen sources
(viz-gliricidia leaf powder, poultry litter and urea) were compared with the standard soya flour
amended compost mixture to study their suitability as potential substitute/s. The addition of
gliricidia leaf powder and urea were determined by the percentage nitrogen (%N) of each com
pound. Percentage N of well-decomposed poultry litter was calculated by using kjeldhal
method (Available N =%N*6.25). The experiment was laid in Complete Randomized Design
with seven treatments and fourteen replicates. The mycelia growth rate after spawning, mush
room yield, and the duration for the first frutification were used as indicators. The results re
vealed that the most suitable compost mixtures for higher mushroom yields were those con
taining 6.6% poultry litter.
