CROP YIELDS AND PRICES 127 



endeavor should be to make the farm a more attractive place, so 

 that it will hold intelligent and forceful men, not as landlords, but 

 as workers. We should raise the rural community to the standard 

 of the American boy and girl, rather than look around the world 

 for someone who is willing to accept life on a farm regardless of 

 its standards. 



Restriction of exportation of phosphorus. The four important 

 plant-foods that are needed in increasing quantities are nitrogen, 

 phosphorus, potassium, and calcium. We have an inexhaustible 

 supply of calcium in our limestone and of nitrogen in the air. 

 Both of these can be supplied to our soils to the extent that prices 

 of crops warrant. Fortunately most of the American- soils in the 

 northern states seem to have a fair amount of potassium. There 

 is enough of this in the mines of Germany to last for an indefinite 

 time. But the supply of phosphorus in American soils is often 

 deficient. This is the chief constituent in most of the chemical 

 fertilizers. The chief source of phosphorus is from the phosphate 

 rock of the Carolinas, Tennessee, and some other southern states. 

 The amount of this rock seems to be limited. 



According to Dr. C. G. Hopkins of the University of Illinois 

 we are now exporting each year as much phosphorus in this rock 

 as would be contained in twice the entire wheat crop of the 

 United States. Germany controls the exports from her potash 

 mines, which appear to be inexhaustible. We give no attention to 

 the exportation of the phosphorus that we are likely to need on 

 our own farms. An investigation of the phosphorus supply and 

 our probable future needs should be made, and the question of 

 limitation of export should be given careful attention, before it is 

 too late. 



SUMMARY 



The wholesale prices of farm products are not very high when 

 compared with the average for the past 73 years. The prices that 

 farmers receive for animal products are higher than the average, 

 but the prices received for crops are generally as low as, or lower 

 than, the 73-year average. For a generation after the opening of 

 the Western prairies, prices were extremely low. In comparison 



