1892.] PUBLIC DOCUMENT — No. 33. 177 



2 differs in yield from Plat 1 , probably on account of a more 

 serious degree of winter-killing, as has been stated on a 

 previous page. Plat 6 shows still the serious influence of 

 several years' fallow (1885 to 1888), without the application 

 of manure and without the cultivation of a crop (black 

 fallow), on the productiveness of the soil thus treated. The 

 low yield of grain (107 to 109 pounds) upon plats 4, 7 

 and 9, which did not receive any nitrogen-containing ma- 

 nurial matter, is a very significant result. The belief in 

 the beneficial influence of a liberal supply of nitrogen on 

 the quantity and the quality of grain crops is evidently well 

 sustained by the results of the above-described experiment. 



