344 



SYSTEMS OF FARMING 



of population of a country the greater the necessity for 

 grain production. 



Grain Farming Has Led to Soil Depletion. — It is common 

 knowledge that wherever grain farming has been practiced exten- 

 sively in the United States soils have become rapidly depleted. 

 The growing of wheat in the pioneer days is a good example. It 

 is for this reason that grain farming is commonly regarded as a 

 soil-robbing or ^^ soil-mining^' enterprise. ' \ 



n.^ 





,^.%*^'n 



Fig. 223. — Stock farming is popular. It puts life into farming. 



Grain Farming Revised. — Fortunately, the relation of crop 

 production to soil fertility is now better understood, so that it is 

 possible for a grain farmer to realize a profit and at the same time 

 maintain, and actually increase, the fertility of his soil. 



The old system of grain farming consisted in the growing of 

 one kind of grain after another, or growing the same crop continu- 

 ously. No effort was made to restore any of the plant-food ele- 

 ments removed by the crops. The straw was burned because it 

 was considered of no value, not even as a fertilizer. 



Scientific research and good farming methods have taught 

 that on most soils the nitrogen and organic matter may be main- 

 tained and increased by practicing a proper rotation including a 

 legume as a green manuring crop, or including both a green 

 manuring crop and another legume as a cash crop. The phos- 

 phorus supply may be maintained by using phosphate fertilizers. 

 The potassium is given little consideration because most of the 

 heavier soils are abundantly supplied with this element. When- 



