MEADOW HAY. 51 



surface and is apparently more capable of obtaining 

 nitrogen from the soil than wheat. Maize has a later 

 period of growth than the cereals already mentioned and 

 will thus have a greater command of the nitrates pro- 

 duced in summer. Owing probably to this fact it is a 

 crop less dependent on nitrogenous manure than wheat. 



Cereal crops derive their nitrogen almost exclusively 

 from nitrates ; the form of organic combination in which 

 the great bulk of the nitrogen is present in the soil is not 

 suited for their assimilation. Notwithstanding, there- 

 fore, the small amount of nitrogen contained in cereal 

 crops, they rank among those most benefited by nitro- 

 genous manures. Phosphates, though generally of little 

 use by themselves, are also beneficial (especially in the 

 case of spring-sown crops) when applied with nitrogen- 

 ous manure. A nitrogenous guano, or a spring dressing 

 of nitrate of sodium and phosphatic slag, or sulphate of 

 ammonia with superphosphate, is generally the most 

 effective manuring for a cereal crop. When malting 

 barley of high quality is to be produced the supply of 

 nitrogenous manure must be carefully limited. Nitrate 

 of sodium always gives a larger return in straw than 

 sulphate of ammonium. 



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 char- 

 acter hay is found to contain a much larger proportion 

 of potash and lime than cereal crops, and a much smaller 

 amount of phosphoric acid. 



