RESULTS OF EXPERIMENTS AT ROTHAMSTED 



PERCENTAGE OF NITROGEN, IN THE DRY SUBSTANCE OF 

 VARIOUS CROPS. 



Not only is the yield of nitrogen per acre much less in the 

 Cereal crops, but the percentage of nitrogen in the dry substance of 

 the Gramineous produce is much less than in that of the Leguminous 

 produce. This is illustrated in Table IV. (below), which shows the 

 average percentage of nitrogen in the dry substance of various crops. 



TABLE IV. 



Average Percentage Nitrogen in the dry substance of various Crops. 



HAY. 



Meadow Hay 

 Clover Hay 



1-79 

 2-89 



Thus it is seen, that the corn of the Leguminous crops, Beans and 

 Peas, contains more than twice as high a percentage of nitrogen in its 

 dry substance as that of the Gramineous grains. The dry substance of 

 the Leguminous straws, also contains about twice as high a percentage 

 of nitrogen as that of the Cereal straws. Again, the dry substance of 

 Clover-hay contains not far short of twice as much nitrogen as that of 

 Meadow-hay. Lastly, the dry substance of the Roots contains about 

 the same percentage of nitrogen as that of the Cereal grains, but only 

 about half as much as that of the Leguminous corn. The leaves of 

 the Root-crops are, however, high in nitrogen. 



The general result is, then, that the non-Leguminous crops, especially 

 those of the Gramineous family, are characterised, both by yielding 

 much less nitrogen in their produce over a given area, and by contain- 

 ing a much lower percentage of nitrogen in their dry substance, than 

 the Leguminous crops. Bearing these facts in mind, let us now turn 

 to the consideration of the effects of direct nitrogenous manures on 

 the various crops. 



