37 



These results are very similar to those obtained at 

 Rothamsted, but are more favourable to the use of am- 

 monia salts. \Yhen the nitrogenous manures were used 

 alone, ammonia salts and nitrate of soda gave practically 

 equal yields. With minerals, a moderate dressing 

 of ammonia salts gave one bushel per acre less than 

 nitrate of soda ; but when double the amount of each of 

 the nitrogenous manures was given, ammonia salts pro- 

 duced over three bushels more than nitrate of soda. The 

 lower weight per bushel of the corn grown with nitrate 

 was even more marked than in the Rothamsted experi- 

 ments, especially when used alone or in the heavier dress- 

 ing with minerals. It should also be noticed that where 

 moderate dressings of the nitrogenous manures were given 

 with minerals, the extra weight per bushel of the corn pro- 

 duced by ammonia salts partly compensated for the smaller 

 quantity ; the difference in the total weight of corn between 

 the two nitrogenous manures being only about 30 Ibs. per acre. 

 The lower proportion of straw to grain with ammonia salts 

 is also seen though not so markedly as at Rothamsted, 

 except with the heavy dressings of the nitrogenous manures, 

 where the additional quantity of nitrate applied seems to 

 have been used by the crop chiefly in the formation of 

 straw. 



As bearing on the quality of the wheat grown with 

 different manures, it is interesting to notice the relative 

 values of the wheat grown on the various plots at YVoburn, 

 in the twenty-first year of experiment 1897.* The values 

 per quarter fixed by practical valuers were 



TABLE XVI. 



No manure 37s. Od. per qr. 



Minerals only 37 



Ammonia salts = 50 Ibs. of ammonia 37 



Nitrate of soda = 50 Ibs. of ammonia 35 



Ammonia salts = 50 Ibs. of ammonia and minerals . 38 6 



Nitrate of soda = 50 Ibs. of ammonia and minerals . 36 



Ammonia salts 100 Ibs. of ammonia and minerals* 38 6 



Nitrate of soda = 100 Ibs. of ammonia and minerals* 36 6 



* Nitrogenous manures applied in alternate years. 



The average value of the corn from the three plots re- 

 ceiving ammonia salts was 385. a quarter, against an average 

 of 355. lod. on the plots receiving nitrate of soda that is, 

 ammonia salts raised the value of the corn is. a quarter 

 above the produce of the unmanured plot, but nitrate re- 

 duced the value to is. 2d. below that of the unmanured 

 corn. These values refer to one season only ; and therefore 

 too much stress must not be laid upon them. But they are 

 probably fairly representative ; being confirmed by the 



* " Journal of the Royal Agricultural Society of England," Vol. IX., 

 Third Series, Part 3. 



