INDOOR COMPOSTING FOR MUSHROOM CULTURE 13 
order to soften the straw sufficiently to enable it to take up water 
readily and to allow the manure to go through its initial violent fer- 
mentation. On the other hand, if the manure has been several days 
on a freight car, the turnings can be made with little or no time inter- 
val, as the object is to break up the manure and moisten it rather than 
to compost it. 
4. Do not allow the pile to remain on the wharf long enough to heat 
above 145° F. or to turn sour after it has been broken up and wet. 
In case a short preliminary fermentation appears to be desirable, it 
will be found that both excessively high temperature and anaerobic 
fermentation can be largely avoided by low piles (2 to 3 feet high) and 
turning at daily or 2-day intervals. Carry the manure into the house 
immediately after the final turning. Fill at the rate of about 150 to 
200 square feet of bed space per ton of wet manure. 
5. After the manure begins to warm up be sure to leave the doors 
and ventilators open enough to prevent overheating during the first 
days of sweating out. If necessary fans should be directed into 
the doorway to prevent overheating. The amount of heat pro- 
duced during the first 2 days is surprisingly great. To maintain 
a temperature of between 120° and 135° F. in the center of 
the beds the air temperature should be regulated approximately as 
follows: First day after filling 90° or below, second day 95°, third day 
98°, fourth day 105°, fifth day 110°, sixth day 115°, seventh day 120°, 
eighth, ninth, tenth days 125° to 130°. The difference between the 
air temperatures and manure temperature will vary somewhat with 
different sources of manure. It should be clearly understood that the 
foregoing schedule of air temperatures is based on estimated differ- 
ences between the air temperature and manure temperature, and that 
the schedule should be modified to keep the manure temperature be- 
tween 120° and 140°. No harm will come from several days at 120° 
or somewhat below, but the manure should under no circumstances be 
allowed to go above 145°, preferably not over 140°. If this happens 
early in the composting the harmful effects of overheating can be 
partly overcome by prolonging the composting 3 or 4 days over the 
normal period, but the chances of obtaining a full crop will be greatly 
reduced. 
6. In most of the experiments at Arlington Farm supplementary 
heat was applied in the form of low pressure steam as soon as the 
temperature began to drop below 125° F., and fans were run during 
the entire composting period to reduce the difference in temperature 
between the top beds and the bottom beds. In commercial practice 
it may be advisable to save electricity and steam by delaying the use 
of steam and the continual running of fans until the last few days of 
the composting period. Most houses may be brought through a fairly 
satisfactory “‘heat’’ during the first week with only an occasional 
running of the fans and no auxiliary heat by allowing the top beds to 
come through peak heat 2 or 3 days ahead of the bottom beds. A 
comparatively low fermentation temperature—120° to 125°—is 
advisable during the first few days of composting to lessen the danger 
of overheating and excessive loss of water while the manure is going 
through its most violent fermentation. During the last 3 or 4 days 
of composting it would seem advisable to reduce the temperature 
differences from the top to the bottom of the house with fans and to 
raise the temperature of the beds to between 130° and 135°. This 
