GENERAL FRUITS. 155 



There is a great difference between a fertile soil aDd a rich one. A fer- 

 tile soil contains all the plant food in a soluble form, ready for imme- 

 diate use. A rich soil contains all the plant food, but most of it is in an 

 unprepared condition for present use. It is an easy matter to exhaust a 

 fertile soil. A few crops of the same kind in succession will do it. Bad 

 cultivation exhausts the fertility of the soil. Dairy cows and growing 

 stock of all kinds are exhaustive to the fertility of the soil. They both 

 require a large amount of lime and phosphoric acid for the growing and 

 replenishing of their bones. This is also required for the milk of the 

 cows. These substances are taken from the green pasture at the expense 

 of the soil. The manure from such stock is of but little value for fertiliz- 

 ing. 



In all cases where the land is cultivated and crops taken from it, the 

 manufacturing of plant food becomes a case of necessity to keep up the 

 fertility of the soil, by returning the same amount or more plant food than 

 was taken from it. To do this we must bring to our aid stock of all 

 kinds and make the saving and composting of all raw or green manure as 

 much of an object as that of growing the various crops. This should be 

 done in a scientific way, and so as to get the whole contents of the 

 manure, and not lose from the half to two-thirds of its most valuable 

 qualities, which is too often the case. 



Those who keep horses, cattle, hogs and other stock will have all of the 

 material to make the very best fertilizers. This should be done by com- 

 posting in the following way: Level off a piece of ground as near your 

 stable as possible. First put down a layer of horse manure, then build 

 up with all kinds of mixed manures, also bones, carcasses and occasion- 

 ally a load of peat. On this throw all the liquors from the drains, soap 

 suds, etc. 



The agents which produce fermentation are air and water. The heap 

 should be moist, if allowed to become hot and dry, the decomposition of 

 the nitrogenous matter, results in the formation of carbonate of ammo- 

 nia, which escapes into the air. This is a great loss. If the heap is suffi- 

 ciently moist the fermentation is slow and instead of carbonic acid being 

 formed and combining with ammonfa, it will stop at the formation of 

 ulmic and humic acid, and these acids with ammonia will form ulmate 

 and humate of ammonia, and compounds of potash and soda. 



By the application of water the heat can be controlled and should not 

 be allowed to exceed 70° or 80°. 



Steaming and the escaping of gas indicates over heat. Care must be 

 taken not to supply water in too large quantities so as to cause a loss of 

 liquor. 



A compost heap should always be under cover. Such a heap as we have 

 described when well rotted, will contain every variety of plant food in 

 concentrated form. Such manure when applied to the moist soil dilutes, 

 and is ready for immediate use if applied at the proper time, and it is of 

 more value to the growing crop than ten times its amount of green man- 

 ure. This kind of manure will be noticed in connection with soils, which 

 follow. Soils are of several kinds, and are classified and known under 

 their proper headings. A sandy loam contains from 60 to 80 per cent, 

 sand, the balance being clay. There is a large amount of this kind of 

 soil in Minnesota. It is usually rich in all the mineral substances, and is 



