i 12) RECEIVED 
Circular No. 609 
May 1941 + Washington, D.C. 
Indoor Composting for Mushroom Culture 
By Epmunp B. Lampert, pathologist, Division of Mycology and Disease Survey, 
Bureau of Plant Industry 
Page Page 
Be VEO UIC i1OT as ee ee 1 | Indoor composting as an improved method for 
Preparation of fresh manure-----..---..----.--- 2| comparing supplements or substitutes for 
METIpPErALUTe | CONUTLO sso See eee 2| mManure___-___ ioe ee ee rege Sa ee ae 
Noistwune;COntrOle-seta.s sao eae as ee 5 | Analysis of variance and design of the experi- 
DurAvionvOl compostin a= == a ee ae 6 MOMS 5 2 a as ee 
Control of fungus diseases and insect pests-__-_--- 7 | Suggestions for commercial growers-_____-------- 12 
Quality and yield of mushrooms-__-_------------- (Summary and: Conclusions.) 2.2222 ssc2. 1 2 2ae es 14 
PPE, 
Recent studies on the preparation of mushroom compost have shown 
that outdoor composting in conventional heaps is relatively inefficient 
because more than half of the manure in these heaps may be decom- 
posing under anaerobic conditions or at excessively high temperatures, 
whereas the most rapid conversion of stable manure to a compost 
suitable for mushroom mycelium takes place under aerobic conditions 
at moderately high temperatures.! In these studies it was also shown 
that fresh manure can be converted into a compost suitable for mush- 
room mycelium in less than 2 weeks, if the temperature is maintained 
between 120° and 140° F., the moisture is properly controlled, and 
aeration is assured, as contrasted with 4 or 5 weeks in outdoor compost 
heaps. 
In as much as it is the usual commercial practice to maintain 
approximately these conditions in mushroom beds during ‘‘sweating 
out”’ following the outdoor composting, it seemed probabie for experi- 
mental purposes at least that compost suitable for mushroom culture 
could be obtained by subjecting trays or beds of fresh stable manure 
to proper conditions. This was confirmed in preliminary experiments 
made in 1938 in which normal yields of mushrooms were obtained 
from beds made up of compost prepared from fresh manure fermented 
entirely by a prolonged sweating out indoors under controlled condi- 
tions with no outdoor composting whatever. The experiments were 
then enlarged so that 6 experimental growing rooms of 48 plots each 
were devoted to determining the requirements for the conversion of 
1 LAMBERT, E. B. STUDIES ON THE PREPARATION OF MUSHROOM COMPOST. Jour. Agr. Res. 62: (In press.) 
309580—41 1 
