49 



increased. Phosphoric acid hastens the ripening and in general the tendency of the 

 plants to fill out the kernels completely, on which account there is more starch and 

 less protein. Plants relatively poor in nitrogen are therefore produced. 



The availability of plant-food is therefore the prime cause of there 

 being so many variations in any one locality corresponding to the soil 

 and manuring on which the crops are dependent. 



Our analyses of oats extend over only one year, but Dr. Maercker in 

 two has shown, as our work has with wheat, that " oats appear to be 

 extraordinarily dependent, even in the same locality, in their compo- 

 sition, on the climatic conditions ruling during the opening period." 

 The crops raised in 1882 and 1883, in exactly the same manner, compared 

 in albuminoids, are as follows: 



Per cent. 



Unmanured, 1882 7.8 



Unmanured, 1883 10.2 



00 pounds per acre of Chili saltpeter, 1882 10. 5 



600 pounds per acre of Chili saltpeter, 1883 12.8 



The difference between these figures for the same year illustrates the 

 effect of nitrogenous fertilizers on the percentage of that element in the 

 grain, it being greater in the manured grain by 2.7 per cent, in 1882 and 

 2.6 per cent, in 1883; and at the same time the effect of the variation in 

 the seasons is as markedly visible. 



Comparing the production per acre with the percentage of nitrogen 

 on the grain it was found that those varieties giving the largest yield 

 were poorest in nitrogen, and the reverse. 



These results, calculated to the amount of nitrogen harvested per 

 acre by the whole plant, explain the differences by showing that all va- 

 rieties collect about the same amount ; consequently, if there is much 

 grain the nitrogen is divided up among it, or if there is much straw the 

 grain is thereby deprived of a certain amount. In 1883 the results 

 were quite different from this. High yields had high percentages of 

 nitrogen, as appears from conclusion 13, previously given. This point, 

 therefore, hardly seems to be entirely settled, but to be largely depend- 

 ent on the climatic conditions of varying seasons. 



For more complete details, reference must be made to the original 

 report upon the experiments, which are models of what should be un- 

 dertaken in our own country. It is of interest, however, to copy cer- 

 13734 Ko. 9 4 



