In order to investigate the compositional change oil composts during the growing of cultivated mushroom (Agaricus bisporus), composts and mushrooms during the period of filling to ending under commercial conditions were subjected to chemical analyses. The results are summarized as follows and the mechanism of composting for mushroom cultivation was proposed.
1) The temperature change of growing bed and room was observed and the yield of mushroom for each cropping time was recorded to get 15.6kg/㎡ in total crops.
2) Composts after filling showed pH 8.2 which dropped to 6.4 after casing and continued so up to ending.
3) On the dry weight basis of composts, crude ash increased whereas total nitrogen, ether extract and crude fibre decreased gradually to bring about the lowering of
organic matter.
4) Total nitrogen of composts decreased gradually ar,d more insoluble nitrogen was lost than soluble nitrogen. The C/N ratio of composts was initially 21 which was gradually lowered to 16.
5) The losses of α -cellulose, pentosan and lignin in composts were 87%, 75%, and 60%, respectively, in which a-cellulose decreased markedly after casing.
6) Free reducing sugars of composts increased continuously. Gradually increased free amino acids till second cropping decreased again thereafter. Composts at the filling stage contained alanine, glutamic acid, glycine and serine in which glycine decreased markedly whereas proline increased remarkably upon mushroom cultivation.
7) Among minerals of composts, phosphorus and zinc tended to decrease, potassium and copper tended to increase anti sodium showed no marked change.
8) In comparison of mushrooms from different cropping time with respect to proximate composition, minerals, free reducing sugars and amino acids, no marked difference was observed. However, a little higher values were observed in crude fat, free reducing sugars and sodium content for early crops and in free amino acids and phosphorus content for late crops. Twelve free amino acids including alanine, serine, threonine, and glutamic acid were detected in the cultivated mushroom.
9) According to above experimental results, it was possible to support the mechanism of compositing that the formation of ammonia and decomposition of carbohydrates by mesophiles are followed by protein biosynthesis, formation of microbial bodies and nitrogen-rich lignin humus complex by thermophiles, thus supplying necessary nutrients for mushroom growth, along with residual carbohydrates.
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