SOIL FOR GREENHOUSES 189 



160. Methods of preparing soils. There are two 

 methods generally used in the preparation of soil for 

 greenhouse benches. The first, and the one most com- 

 monly used on smaller ranges, "is the compost method, 

 usually known as the compost heap ; the second method 

 has more recently come into favor, especially with large 

 rose- and carnation-growers, and is known as the field 

 preparation of soil. 



The compost method. For small ranges where many 

 varieties of plants are grown, the compost method is, 

 without doubt, the most satisfactory. It is expensive, 

 however, as it requires much hand labor, and unless the 

 soil is frequently turned, there is a possibility that it 

 may become sour. The compost heap should be con- 

 veniently located, and if the moisture contents can be 

 governed, the results will be more satisfactory. Under 

 dry conditions, sods decay slowly, and if it is necessary to 

 hasten the process, the compost heap can be soaked occa- 

 sionally with a hose. 



As before stated, pasture sod is rich in its fiber content. 

 If pasture sod which contains mineral substances in the 

 right proportion can be obtained, it makes a most ideal 

 compost. If such is not available, the sod should be 

 selected from mowings w r hich have been in sod for a 

 considerable period. It should be pared off to a depth 

 of four or five inches, and this should be done in the early 

 fall. The sod is taken to the spot selected for the com^ 

 post heap. It is piled in heaps about five or six feet high, 

 six feet wide, and any desired length. Piles of this width 

 can be turned easily and conveniently by two workmen. 

 A layer of sod of definite thickness is followed by a layer of 

 manure (Fig. 21). The thickness of this layer of manure 

 depends on the fertilizing requirements of the crop to be 



