SOILS AND FERTILIZING MATERIALS 33 



the same field may prevent a fair comparison of 

 the action of different kinds of fertilizing materials 

 and elements. But, notwithstanding such diffi- 

 culties, valuable suggestions will be gained from 

 an experimental study of the soil through the 

 behavior of the crops. 



It is a fact of great interest and importance that 

 one form of a fertilizing constituent is preferred 

 by some plants to the same constituent in another 

 form. This perference is indicated by greater 

 yield or better quality of product or by both. 

 Thus, wheat seems to give better results when 

 nitrogen is applied in the form of nitrate of soda 

 than in any other form. The quality of tobacco 

 is injured by potash in the form of muriate and, 

 hence, only sulphate of potash should be used 

 for fertilizing purposes. The quality of sugar 

 beets and of potatoes appears to be better when 

 sulphate of potash is used. 



While the soil may contain quantities of fer- 

 tilizer naturally, in most cases it will not pay to 

 give serious attention to this source of fertiliza- 

 tion. Nitrate of soda, when used alone should 

 always be applied to growing crops, and for quick 

 effects. For young fruit trees or for vegetables, 

 one or more applications may be made with bene- 

 fit. Complete fertilizers usually have a small 

 proportion of their nitrogen in the form of nitrate 

 of soda, and the remainder in a less active form, 

 so that by the time the nitrate of soda is utilized, 

 the nitrogenous products become effective. 



