Volume 12 Part 1 Article 42
Title: Nutritional Supplementation to the Casing Soil: Ecological Aspects and Mushroom Production
Authors: Segula Masaphy, D. Levanon, 0. Danai and V. Henis
The most widely grown edible mushroom, Agaricus bisporus, requires two different substrates to form its fruit bodies; i.e. the compost, in which it grows vegetatively, and the poor-nutrient casing soil in which the suitable physical, chemical and biological conditions stimulate the initiation process and fruit body production (10). The biological conditions include the development of a suitable bacterial flora (6, 7) which is dominated by Pseudomonas species (5, 11, 12).
Although it is agreed that the casing layer should be poor in nutrients (4, 9, 17) in order to produce fruit bodies, there is no agreement on the most important factor involved. It was suggested that the casing should be low in nutrients (such as lignin) that serve as a potential source of quinones by laccase activity (17). This hypothesis however was not supported by the favourable effect of cabutz, high in cellulose and lignin, used as a casing layer for mushroom production of A. bisporus in Israel (14). Furthermore, according to Barnard (2), fruit bodies formation is inhibited by the addition of soluble nitrogen to the casing soil.
However, it is agreed that a good casing soil should be low in soluble ions and should have a low conductivity (10).
The present research dealt with the effect of supplementation of the casing layer with carbohydrates and nitrogen sources on the microbial population of the casing layer and on the A. bisporus growth and fruit bodies formation.