Biological efficiency of Agaricus brasiliensis cultivated in compost with nitrogen concentrations

The production of compost is one of the most important steps for the cultivation of any species of mushroom. For the Agaricus species, this step is even more complex because it depends on the performance of different microorganisms that act on the substrate, turning it into selective compost that promotes the growth of the fungus to be cultivated. Among the various factors that affect the microbial activity, the initial concentration of nitrogen is considered one of the most important. Due to the lack of conclusive studies about that, the aim of this study was to evaluate the productivity and biological efficiency of Agaricus brasiliensis in compost prepared with different initial concentrations of nitrogen, according to the composting methodology and to the conventional pasteurization techniques (phase I and II). Three initial nitrogen concentrations (w/w) (T-1 = 1.0%; T-2 = 1.5%; and T-3 = 2.0%) were tested and mycelial growth was determined in terms of mm/day for all treatments. The productivity and biological efficiency were also determined. The most efficient initial concentrations of nitrogen were of 1.0% and 1.5%. This concentration of N in the compost permitted a faster development of the mushroom with higher productivity when compared to the results obtained with the application of 2% of nitrogen.