88 AMERICAN WHEAT AND CORN. 



in the straw in potash and silica. With ammonium-salts alone there 

 was, over the second period, in the grain slight deficiency of potash and 

 magnesia, and greater in phosphoric acid, but there was slight increase- 

 in lime and sulphuric acid. In the straw there was more marked de- 

 ficiency in every constituent, excepting sulphuric acid, and the defi" 

 ciency is the most marked in potash, phosphoric acid, chlorine and silica,, 

 though chlorine is largely supplied in the ammonium salts. 



12. Upon the whole, the comparison of the yield of ash constituents- 

 per acre over the first and second eight years shows, without manure 

 a small relative exhaustion of both potash and phosphoric acid, and with 

 ammonium-salts a greater relative exhaustion of both. 



13. Per 1,000 dry substance of grain there were taken the average of the 

 sixteen years, almost identical amounts of each of the ash-constituents 

 without manure, and with farm-yard manure; but with ammonium-salts 

 alone there was marked deficiency, especially of phosphoric acid, and ia 

 a less degree of potash. Per 1,000 dry substances of straw, there was,, 

 without manure considerably less potash than with farm-yard manure,, 

 but otherwise not much difference. With ammonium-salts alone there 

 was still greater deficiency of potash, but more lime, less phosphoric 

 acid, but more sulphuric acid, and considerably less silica, than either 

 without manure or with farm-yard manure. 



14. Comparing the amounts of ash constituents per 1,000 dry substance 

 of the grain, over the first and second eight years, with farm-yard manure 

 they are almost identical over the two periods, and without manure very 

 nearly so, but there is slightly less potash, and more magnesia and 

 phosphoric acid, over the second period conditions indicating less per- 

 fect maturation, that is, less flour in proportion to bran. With ammo- 

 nium-salts alone the dry substance of the grain shows a markeil defi- 

 ciency of potash and magnesia, and especially of phosphoric acid com- 

 pared with that of the other plots; it nevertheless shows very little 

 difference comparing the second eight years with the first, though there 

 is a slight decrease of phosphoric acid and increase of sulphuric acid 

 and silica over the second period. 



15. Per 1,000 dry substance of the straw, the amount of the various 

 ash-constituents varies more over the two periods than in the case of 

 the grain, but still comparatively little. Without manure there is over 

 the second period a deficiency of potash and magnesia, partially com- 

 pensated by lime, also a deficiency of phosphoric acid. With ammonium- 

 salts, the most marked deficiency over the second period is of potash ^ 

 there is also less chlorine, but more sulphuric acid. 



16. In conclusion in regard to this first series of ash analyses, although 

 the results show a much wider range of variation in the mineral com- 

 position of the grain due to season than to manuring, there are still dis- 

 tinct differences due to the very different conditions as to manuring^ 

 but with each of the three conditions there is comparatively little differ- 

 ence over the first and the second eight years. With ammonium -salts. 



