In general we might speak of three different methods in the curing of the manure. First, the slow process of curing. According to this method, which is practiced by some, the time of fermentation may extend from four to five weeks. In this case the manure is piled in such a way that the temperature does not rise rapidly. During the four or five weeks the manure is turned four or five times. The turning occurs when the temperature has arisen to such a point as to require it.

Another method, used by some, might be called a rapid process of curing. According to this, the time for curing the manure extends over a period of about a week, or five to ten days. The material is piled in such a way as to cause rapid fermentation and rapid rising of temperature, the material sometimes requiring to be turned every day or two, sometimes twice a day, in order to lower the temperature and prevent the material from burning or drying out. Between this rapid process of curing, and the slow process of curing, the practice may extend so that, according to the method of different operators, the period of curing extends from one week to a month or five weeks.

Figure 231.—View in mushroom house (L. S. Bigony's Mushroom Plant, Lansdale, Pa.), showing alley and side tier of beds. Copyright.

The third method of curing consists in putting the material at once into the beds before curing, and mixing in with the manure, as it is placed in the bed, about one part of loam or garden soil to four or five parts of the fresh manure. The material is then left in this condition to cure without changing or turning, the temperature rising perhaps not above 130° F. With some experience in determining the firmness with which the bed should be made to prevent a too high rise of temperature, this practice might prove to be successful, and would certainly save considerable labor and expense in the making of the beds. Mr. William Swayne of Kennett Square, Pa., in the winter of 1900–1901, made up a portion of one of his beds in this way, and no difference could be seen in the results of the crop, the crop from the beds made in this way being as good as that of the adjoining beds, and he intends the following year to make up all of his beds in the same way.

Mixing soil with the manure at the time of fermentation.—While in the cave culture of mushrooms the manure is usually fermented and used without the admixture of soil, usually in the house or cellar culture rich loam soil, or rotted sod, is mixed with the manure at the time of turning it, during the process of fermentation. At the time of the first turning, soil is mixed in, a layer of the manure being spread out on the ground, and then a sprinkling of soil over this. Then another layer of the manure is added with another sprinkling of soil, and so on as the new pile is built up. In the first turning of the manure, about one part of soil is used to eight or nine parts of manure. Then at the last turning another mixture of soil is added, so that there is about one-fifth part soil in the mixture. The soil aids somewhat in lowering the temperature, and also adds some to the bulk, so that more beds can be made up with the same amount of manure.

Horse droppings free from straw.—For growing mushrooms on a small scale, as in cellars or boxes, some prefer to select the horse droppings free from straw.

[MAKING UP THE BEDS.]

Making up beds without the addition of soil.—In the cave culture of mushrooms the beds are usually made from manure alone, there being no addition of soil. This is perhaps partly due to the expense of getting the soil in and out from the caves as well as to the low temperature prevailing there. It is believed by many that the results are equally as good in beds from the manure alone as in those which contain an admixture of soil. The method of making the beds in the Akron cave, or "tunnel," is as follows: The manure, immediately after it has passed through the process of fermentation and curing in the pile, is carted to the district in the mine where the beds are to be made and is dumped in a long windrow on the ground. The length of the windrow depends of course upon the amount of material which is ready, as well as upon the amount necessary for making up the beds for that distance. Two hemlock boards, sixteen feet long and ten inches wide, and two, four feet long and the same width, are then hastily nailed into the form of a rectangular frame. This is placed upon the rock bottom at one end of the row of material, perpendicular to it usually.