416 THE HOME, FARM AND BUSINESS CYCLOPEDIA. 



fact, the most constant of all the constituents of crops ; it is chiefly con- 

 centrated in the grain. Potash and lime are present in much smaller 

 quantity than in other crops ; they are chiefly concentrated in the straw. 



The presence of a large amount of silica is characteristic of the cereal 

 crops ; they possess apparently a capacity for feeding on silicates not en- 

 joyed by other crops. The base of the silicate is made use of by the 

 plant, while the silica itself is excreted upon the surface of the leaves and 

 straw. It has been shown that silica is by no means essential for the 

 growth of cereals ; they take it up freely, but can also do without it. 



The, fall sown cereals (wheat and rye) have both deeper roots, and a 

 longer period of growth, than the spring sown cereals, and are better able 

 than the latter to supply themselves with the necessary ash constituents 

 from the soil. Barley possesses a considerable development of root near 

 the surface, and is apparently more capable of obtaining nitrogen from the 

 soil than wheat. 



Cereal crops derive their nitrogen almost exclusively from nitrates ; the 

 form in which the great bulk of the nitrogen is present in the soil is un- 

 suitable for them. Notwithstanding, therefore, the small amount of 

 nitrogen contained in cereal crops, they rank among those most benefited 

 by nitrogenous manures. Phosphates, though of little use by themselves, 

 are also beneficial (especially in the case of spring crops) when applied with 

 nitrogenous manure. A nitrogenous guano, or an application of nitrate of 

 sodium and superphosphate, is generally the most effective manuring for 

 a cereal crop. 



MEADOW HAY. The grasses which form the main bulk of hay belong 

 to the same family of plants as the cereal crops ; the seed, however, in 

 grass bears such a small proportion to the stem and leaf that meadow hay 

 may be regarded as a straw crop. In accordance with this character hay 

 is found to contain a much larger proportion of potash and lime than 

 cereal crops ; and a much smaller amount of phosphoric acid. 



The roots of grass being far shorter than those of the cereals are less 

 able to collect ash constituents from the soil ; if therefore grass is mown 

 for hay, manures containing potash, lime, and phosphoric acid will gen- 

 erally be required. Like the cereal crops grass is greatly increased in 

 luxuriance by the application of soluble nitrogenous manures. 



Farmyard manure, or the feeding of cake, grain, or roots on the land, is 

 the most appropriate manuring for permanent pasture, if quality as well 

 as quantity of produce is considered. Large crops of hay may be obtained 

 by manuring with nitrate of sodium, together with kainit and super- 



