Volume 12 Part 1 Article 36
Title: Supplementation of Agaricus Compost with Organic Materials with Special Attention to the Uptake of Minerals and Amino Acids
Author: J.P.G. Gerrits
It is now exactly 25 years ago that it was published for the first time that mushroom yield can be increased considerably by adding organic materials to the compost, either at spawning or at casing. Thus procedure is now generally known as supple mentation and has received a lot of attention in various parts of the world. I will only mention the work of Carroll and Schisler (1976) concerning formaldehyde and heat treatments of proteinaceous products which led to a patent concerning slow release nutrients. All work on supplementation has been reviewed recently by Randle (1983).
In the Netherlands, soya bean meal treated witii 3000 ppm formaldehyde has been used successfully during the past five years (Gerrits 1983, 1986). Supplementation enhances the growth of mesophilic fungi in the compost. This effect is counteracted by treating supplements with formaldehyde (Gerrits and Moore 1986).
Supplements should be added to well run compost immediately laefore casing. The optimum amount is about 1 kg per m2, corresponding to 3 to 4 % of the substrate dry weight. In general it is not advisable to supplement on a dry matter basis, however, because deep layers will receive more supplement than this 1 kg per m2. Difficulties in temperature control may then arise due to excessive amounts of compost and supplement. In fact, the amount of supplement per m2 has to be decreased with increased compost density.
Under ideal circumstances, yield can also be increased by other products such as feather meal.
In a recent series of trials, various products were added to spawn-run compost at the rate of 0, 0.5, 1.0 or 1.5 kg per m2. A striking variation in effect between the various products was assessed. These trials will he discussed in this paper.
Amino adds and several minerals were determined for a number of composts and the resulting mushrooms.
These data indicate which elements are withdrawn from the compost by growing mushrooms. Further, the effect of a formaldehyde treatment on various products other than soya bean meal was studied.Please login to download the PDF for this proceeding.