Figure 226.—Single mushroom house (Wm. Swayne, Kennett Square, Pa.), "curing" shed at left. This house is heated in connection with other hothouses.
Probably at Paris, and perhaps also at some other places where the system of ridge beds is used, the question of the cost of the lumber is an important one, and the system of ridge beds avoids the expense of this item of lumber. In other cases, where the flat beds are used with the board supports, the cost of lumber is considered a small item when compared with the additional labor involved in making the ridge bed. The flat beds are very quickly made, and the material in some cases is not more than 7 inches deep, allowing a large surface area compared with the amount of food material, for the growth of the mushrooms. It may be possible, with the flat, shallow bed system, that as many or more mushrooms are obtained from the same amount of manure, as in the case of the ridge beds. When we consider the cost of the manure in some places, this item is one which is well worth considering.
[THE HOUSE CULTURE OF MUSHROOMS.]
Where this method of cultivation is employed, as the main issue, houses are constructed especially for the purpose. In general the houses are of two kinds. Those which are largely above the ground, and those where a greater or lesser pit is excavated so that the larger part of the house is below ground. Between these extremes all gradations exist. Probably it is easier to maintain an equable temperature when the house is largely below ground. Where it is largely above ground, however, the equability of the temperature can be controlled to a certain extent by the structure of the house. In some cases a wall air space is maintained around the sides and also over the roof of the building. And in some cases even a double air space of a foot or 18 inches each is maintained over the roof. In some cases, instead of an air space, the space is filled with sawdust, single on the sides of the house, and also a 12 or 18-inch space over the roof. The sides of the house are often banked with earth, or the walls are built of stone or brick.
Figure 227.—Double mushroom house (L. S. Bigony's Mushroom Plant.) Packing room at left, "curing" shed at right, next to this is boiler room.
All of these houses, no matter what the type of construction, require ventilation. This is provided for by protected openings or exits through the roof. In some cases the ventilators are along the side of the roof, when there would be two rows of ventilators upon the single gable roof. In other cases a row of ventilators is placed at the peak, when a single row answers. These ventilators are provided with shut-offs, so that the ventilation can be controlled at will. The size of the house varies, of course, according to the extent of the operations which the grower has in mind.
The usual type of house is long and rather narrow, varying from 50 to 150 feet long by 18 to 21 or 24 feet wide. In some cases the single house is constructed upon these proportions, as shown by Fig. [226], with a gable roof. If it is desired to double the capacity of a house, two such houses are built parallel, the intercepting wall supporting the adjacent roof of the two houses, as shown in Fig. [227]. A still further increase in the capacity of the house is often effected by increasing the number of these houses side by side. This results in a series of 8 or 10 houses forming one consolidated block of houses, each with its independent ridge roof and system of ventilation. The separating walls between the several houses of such a block are probably maintained for the purpose of better controlling the temperature conditions and ventilation in various houses. If desired, communication from one house to another can be had by doors.
Interior structure and position of the beds.—The beds are usually arranged in tiers, one above the other, though in some houses the beds are confined only to the floor space. Where they are arranged in tiers in a house of the proportions given above, there are three tiers of beds. There is one tier on either side, and a tier through the middle; the middle tier, on account of the peak of the roof at this point, has one more bed than the tiers on the side. The number of beds in a tier will depend on the height of the house. Usually the house is constructed of a height which permits three beds in the side tier and four in the center tier, with an alley on either side of the center tier of beds, giving communication to all. If the house is very long and it is desirable, for convenience in passing from one house to another, to have cross alley-ways, they can be arranged, but the fewer cross alleys the larger surface area there is for beds.