in.] YIELD WITH INCREASING NITROGEN 8i 



Considering the total produce as a measure of the 

 growth, it will be seen that the increase produced by 

 the second 43 lb. of nitrogen is almost as great as that 

 due to the first, but that the third application gives a 

 smaller, and the fourth a still smaller increase. 



As the nitrogen increases the character of the 

 development changes, the extra growth is seen more in 

 the straw — z>., in the vegetative parts of the plant — than 

 in the grain ; the fourth addition of 43 lb. nitrogen only 

 increases the yield of grain by half a bushel, but the 

 straw is greater by 3-9 cvvts. The proportion which the 

 grain bears to the straw — 62 per cent, when no nitrogen 

 is used — drops with each increment of nitrogen, and falls 

 to 48 per cent, when 172 lb. of nitrogen per acre are 

 applied. An excess of nitrogen also tells upon the 

 quality of the grain, as judged by the size of the berry 

 and the weight per bushel. The weight per bushel 

 increases for the first application of nitrogen, but after 

 that it becomes less and less with each increment; 

 other results from the same field show a parallel varia- 

 tion for the weight of a hundred grains and for the 

 average market value of the corn from the different 

 plots. 



When dealing with barley, an exactly similar state 

 of things prevails : the proportion the grain bears to 

 the straw decreases with each addition of nitrogen ; 

 while as regards the quality of the grain, the weight per 

 bushel falls, the percentage of nitrogen increases, and 

 the barley takes on all the appearances that are summed 

 up as " coarse." This is due to the fact that the glume 

 and pale, vegetative parts, are pushed on out of propor- 

 tion to the endosperm, so that the berry is light and 

 appears thick-skinned ; at the same time the colouring 

 matter is increased, though this is more apparent in the 

 ear than in the grain. 



