«1 



tilled crops, is far better than it is to starve the grass and food for 

 put all the added Fertility on the " cash " crop. Why? P'^"*^ 

 Because the very root development and soil shading which 

 have enabled the grasses to utilize so well the natural food 

 in the soil, also fit them to gather most completely and to 

 use most efficiently the scattered fertility which man dis- 

 tributes upon the fields. With the added growth the 

 grasses make upon the extra supply of food, there comes 

 an increase in the number of roots to fill the soil with 

 vegetable matter, and an increase in the amount of scattered 

 leaves, broken stems and refuse matter on the surface, — all 

 of which is of inestimable advantage to subsequent crops. 

 The soil is thus made fine and porous; the decay of green 

 vegetable matter forms acids which set free additional plant 

 food from the particles of earth ; and the accumulated 

 humus makes the ground like a sponge to hold moisture 

 for the next crop. 



Properly proportioned mineral fertili- 

 zers have a great and profitable effect upon ^ ^ ^^ 



the yield of hay from treated fields, as is »,. , /,, 



•^ , , u L L • Mmeral Chemi- 



most clearly shown by the experiments . p ... 



here discussed; and they improve the 



quality of the hay, as well. As shown, such a fertilizer for 



grasses must contain a liberal amount of a readily soluble 



form of Nitrogen. Clover can get along very well without 



Nitrogenous fertilizers, as it has the power to draw upon 



the store of Nitrogen in the air; but the true grasses lack 



this ability, and, though they may be well provided with 



phosphoric acid and potash, are not able in the absence of 



a supply of readily available Nitrogen to compete with 



clover when sown in a mixture with it. In consequence of 



this fact, mixed hay is quite likely to be largely clover the 



first year after sowing and therefore of less value in the 



market than the highly prized "clear timothy." The 



addition of Nitrogen in the quickly soluble form of 



Nitrate of Soda gives to the grasses a supply of food which 



promotes luxuriant growth and thus furnishes just the 



impulse they need to keep them abreast of the clover, or 



ahead of it, and also to improve the quality of the hav to 



a very striking degree. 



