78 MASSACHUSETTS HORTICULTURAL SOCIETY. 



potash. In many cases it is not the lack of any particular article 

 which makes soils infertile, but other circumstances. 



The feeding capacities of plants are most important, but we are 

 deplorably in the dark as to why they differ. Leguminous crops 

 gather nitrogen ; why is it? Clover takes away much more nitro- 

 gen from the soil than wheat ; yet it is much less dependent upon 

 nitrogen in fertilizers, though this is contrary to what theory would 

 lead us to expect, and further experiment is needed to give light 

 upon this point. 



The result of the experiments under my direction in the use of 

 nitrogen, in different forms, in several places, and two or three 

 times repeated was that for every 100 bushels of corn obtained 

 with mixed mineral fertilizers we get by adding 24 pounds of 

 nitrogen per acre. 111 bushels ; with 48 pounds of nitrogen, 112; 

 and with 72 pounds of nitrogen in addition to the mixed minerals, 

 115 bushels. The yield of corn was slightly increased by the 

 nitrogen, but the gain was extrerael}' small — out of all proportion 

 to the large cost of nitrogen. Potatoes gave a much more decided 

 response to the nitrogen, 24 pounds increasing the yield from 100 

 to 127, 48 pounds bringing it up to 138, while with 72 pounds it 

 was only 127. The number of experiments with potatoes was 

 much smaller than with corn. A larger number might give differ- 

 ent averages. Oats responded much more vigorously to the nitro- 

 gen, the yield rising to 171 with the largest amount, though the 

 number of experiments was less even than with potatoes ; but, 

 since in the cases where oats, potatoes, and corn were grown side 

 by side the results tallied with the average given, the experiments 

 may be taken as indicating very decidedly that corn is the least 

 and oats the most affected by the nitrogen in the fertilizers. 

 These experiments, as far as they go, therefore imply that we 

 should in general be sparing in our use of nitrogen for corn, 

 that we may use moderate quantities on potatoes with profit, and 

 that oats are especially benefited by it. 



There was, however, one notable exception to this result. In 

 some experiments by Mr. W. C. Newton, of Durham, Conn., he 

 found when he measured his corn that he could almost tell the 

 number of pounds of nitrogen applied by the increase in the crop. 



The results of these experiments have been tabulated and 

 arranged, and the story which they tell is somewhat peculiar. 



