90 AMERICAN WHEAT AND CORN. 



Per 1,000 dry substance of the straw, there was also more potash, less 

 phosphoric acid, and more sulphuric acid in the better seasons. 



6. Calculated per acre, there was about twice as much grain, nearly 

 one and a half times as much straw, and more than one and a half times 

 as much total produce in the best as in the worst of the four seasons. 

 Of total nitrogen in the crop per acre, there was an average of only 38 

 pounds in 1852, and of 50.1 pounds in 1863; while of the less total 

 quantity in 1852 a considerably larger actual amount remained in the 

 straw. In 1852, 61.6 per cent. ; in 1856, 72.9 per cent. ; in 1858, 73.8 per 

 cent., and in 1863, 77.4 per cent, of the total nitrogen of the crops was 

 stored up in the grain. In 1863, with the largest actual amount of ni- 

 trogen in the grain per acre, there was the lowest percentage of it in the 

 grain ; that is, under the influence of the very favorable growing and 

 rnaturiirg conditions, there was a greater accumulation of non-nitroge- 

 nous constituents in proportion to the amount of nitrogen stored up. 



7. Calculated per acre, there was in 1863 one and a third times as much 

 total mineral matter in the crop as in either of the other years. Com- 

 paring the best and the worst seasons (1863 and 1852), there was one 

 and a half times as much lime, magnesia, and phosphoric acid, and about 

 twice as much potash and sulphuric acid in the total produce per acre 

 in the season of most favorable growth and maturation. Yet, per 1,000 

 dry substance of the grain, the amounts of lime, magnesia, and phosphoric 

 acid were lower, and the amount of potash was not much higher in the 

 better seasons. 



8. Taking the average results over the four years, for each of the nine 

 different conditions as to manuring separately, there is, with one or two 

 -exceptions, comparatively little variation in weight per bushel with the 

 equal season, but very varying manuring conditions; and the differ- 

 ences, such as they are, are consistent. The percentage of nitrogen is 

 also in the main fairly uniform with the different manures; but it is low 

 with mineral manure alone and great nitrogen exhaustion, and high 

 with ammonium-salts alone and relatively excessive nitrogen supply. 



'The percentages of total mineral matter are also fairly uniform, but 

 somewhat higher with farm-yard man tire, without manure, and with min- 

 eral manure alone, and low with ammonium-salts alone. 



9. Per 1,000 dry substance of the grain there is also general uniformity 

 in the amount of the chief individual ash constituents under the very 

 -different manuring conditions. The exceptions to uniformity in the 

 amounts of potash are, that it is somewhat high without manure and with 

 purely mineral manure, and somewhat low with ammonium-salts alone, 

 and with ammonium-salts and superphosphate, but without potash. 

 The exceptions to general uniformity in the amounts of phosphoric acid 

 are, that it is high with farm-yard manure, without manure, and with 

 purely mineral manure, and low with ammonium-salts alone. 



10. Per 1,000 dry substance of the straw the amounts of the individual 

 constituents are much more variable on the different plots. The 



