78 The Sugar-Beet in America 



While applying nitrogen in a form to encourage steady 

 and continuous growth would result in a large yield, it 

 would also produce beets low in sugar. In order to en- 

 courage the desirable early growth, nitrogen should be 

 supplied largely in the readily available form in the 

 spring before planting; organic, or slow-acting, forms 

 should not be applied at that time. 



When beets are raised for stock feed, fertilizing should 

 be done in such a way that rapid and continuous growth 

 is secured. This is accomplished by large applications of 

 nitrogen and phosphoric acid throughout the season, 

 especially the former. The liberal use of farm manure 

 would be desirable in this connection, especially on heavy 

 soils. On light soils all the fertilizer elements could be 

 supplied as commercial fertilizers. 



A discussion of the sources of the various fertilizer 

 elements follows. 



Nitrogen. 



The most expensive of all the fertilizer elements is 

 nitrogen. The supply of this element is also limited. 

 Formerly, it was obtained in the form of guano, which is 

 manure and decayed bodies of birds, but this supply is 

 now practically exhausted. At present the chief source 

 is the beds of sodium nitrate, or Chile saltpeter, found 

 in Chile. It lies near the surface of the ground in great 

 beds, but is so mixed with rock and earth that the leach- 

 ing out of the salt is necessary before it is ready for market. 

 Nitrogen in the form of sodium nitrate is directly avail- 

 able to plants. 



Ammonium sulfate is another important source of 



