Fertilizers and Shade-crops 185 



In several western regions the land was planted con- 

 tinuously to wheat in the early days, and, as any one would 

 now expect, the soil became depleted and in some instances 

 the farmers faced bankruptcy. This same land is now 

 producing immense crops of wheat, oats, sugar-beets, 

 potatoes, and alfalfa. What has brought about the 

 change? Alfalfa was introduced about the year 1860. 

 It was adapted to our conditions from the first, and large 

 areas of this land were soon growing luxuriant crops of 

 this unexcelled forage plant. The feeding of animals was 

 then in its. infancy, and alfalfa soon became a drug on the 

 market. It was then found that alfalfa sod could be suc- 

 cessfully broken, and, much to the surprise of all, when 

 planted to wheat, the yield per acre was far greater than 

 when the land was first subdued. 



What had alfalfa done to the soil ? It had added some 

 nitrogen, which it is able to gather from the soil-air by 

 the aid of the nitrogen-fixing bacteria. It also brought 

 up from the lower depths, ten or more feet below the 

 surface, potassium and phosphorus. These two impor- 

 tant elements of plant-food were deposited in the surface 

 soil in the shattered leaves and stems as crop after crop 

 was removed, and when the sod was broken, the decaying 

 roots and stubble added their quota. But more impor- 

 tant than all these, decaying vegetable matter and its 

 products had been added to the soil. Without decaying 

 vegetable matter the physical condition of the soil is 

 almost ruined for agricultural purposes, and the hosts 

 of bacteria that perform many essential activities are 

 prevented from developing. 



Our orchards have been planted, for the most part, on 



