AMERICAN WHEAT AND CORN. SO 



alone, where there is very abnormal mineral exhaustion, the dry sub- 

 stance of the grain shows relative deficiency of both potash and phos- 

 phoric acid, but especially the latter. Upon the whole the results point 

 to great uniformity in the mineral composition of the grain under the 

 different conditions of manuring, provided only that it is perfectly and 

 normally ripened- High or low percentage of nitrogen is also more de- 

 pendent on the conditions of maturation than on full or limited supply 

 of it by the soil. 



SECOND SERIES OF ANALYSES. 



1. This series relates to the produce obtained under nine different 

 conditions as to manuring, each in two unfavorable, and in two favor- 

 able seasons for the crop. They thus illustrate the influence of charac- 

 teristic seasons under a great variety of manuring conditions. 



2. The manuring conditions were : Farm-yard manure ; without ma- 

 nure; superphosphate, and sodium, potassium, and magnesium sul- 

 phates ; ammonium-salts alone ; ammonium-salts and superphosphate ; 

 ammonium-salts, superphosphate, and sodium sulphate; ammonium- 

 salts, superphosphate, and potassium sulphate; ammonium-salts, super- 

 phosphate, and magnesium sulphate ; ammonium-salts, superphosphate,, 

 and sodium, potassium, and magnesium sulphates. 



3. The four seasons were : 1852 and 1856, which were unfavorable^ 

 and 1858 and 1863, which were favorable for the crop; 1852 (the ninth 

 from the commencement of the experiments) was bad both as to quan- 

 tity and quality of produce ; 1856 gave fairly average quantity both of 

 grain and straw, but the crop was unevenly ripened, and the quality of 

 the grain was low ; 1858 yielded only a moderate amount of total pro- 

 duce, but more than average proportion and amount of grain, which 

 was of over average quality ; 1863 (the twentieth year of the experi- 

 ments) was the best both as to quantity and quality of produce through- 

 out the forty years, 1844-1883, inclusive, 



4. Taking the mean results of the nine plots in each of the four sea- 

 sons, there was from the first to the fourth season an increase in the 

 weight per bushel of the grain, and in the proportion of grain to straw,, 

 and a decrease in the percentages of nitrogen and total mineral matter 

 in the dry substance of the grain. Coincidently with these characters,, 

 there was, from the first to the fourth season, great increase in the per- 

 centage of potash, and considerable decrease in that of magnesia, and 

 there was great decrease in the percentage of phosphoric acid, and an. 

 increase in that of sulphuric acid, in the grain-ash. 



5. Calculated per 1,000 dry substance of the grain, there was more 

 potash and less magnesia, and especially much less phosphoric acid, and 

 some more sulphuric acid in the produce of the two later and better 

 seasons. These are indications of higher proportion of flour to bran,, 

 that is, of more starch. The variation in the mineral composition is, 

 thus associated with variation in the organic composition of the graiiu 



