Using locally available chicken manure as a substitute to horse manure in compost formulas for growing Agaricus bisporus in Lebanon

Mushroom production is rising in Lebanon facing the high demand for this highly nutritious food. However, the growth of this sector is faced by one major constraint that is the high production cost due to the need to import the conventional compost substrates at high prices from the Netherlands or the USA. Thus, efforts were done through this study to formulate a local compost mixture based on widely available chicken manure and to investigate its potential use for growing the white button mushroom (Agaricus bisporus) in small scale production. Mushroom yield and quality were evaluated among 5 compost mixtures: 100% conventional compost (based on horse manure) (control) (A), 70% conventional compost + 30% local compost (based on chicken manure) (B), 50% conventional compost + 50% local compost (C), 30% conventional compost + 70% local compost (D) and 100% local compost (E). Results showed that average mushroom number and yield produced in the mixtures B, C, and D were not significantly different compared to control (around 40 mushrooms and 2.5 kg box^‑1 for the 4 mixtures). The mixture E was the least productive. Average individual mushroom weight obtained in B (61 g), and C (60 g) did not significantly differ compared to A (66 g) and was higher than D (48 g) and E (42 g). Mushroom length and cap diameter were the best in the mixtures A compared to all other mixtures. Mushroom nutritional composition (crude fibers, proteins, fat, water, P, Mg, Fe, Cu, Al, Zn, Na, K and Ca content) in all mixtures containing local compost was close to that of control and in the mixture B mushroom composition was almost the same compared to A. The use of local compost would provide an efficient way to recycle chicken manure for further agricultural use and would allow reduction in the mushroom production costs.