196 TALKS ON MANURES. 



The summer of 1850 was unusually cool and unfavorable for 

 wheat. It will be seen that on all the plots the yield of grain is 

 considerably lower than last year, with a greater growth of straw. 

 You will notice that 106, which last year gave, with ammo- 

 nia-salts alone, 82 bushels, this year, with superphosphate, potash, 

 soda, and sulphate of magnesia, gives less than 18 bushels, while 

 the adjoining plot, dressed with ammonia, gives nearly 27 bushels. 

 la other words, the ammonia alone gives 9 bushels per acre more 

 than this large dressing of superphosphate, potash, etc. 



On the three plots, 8a, 8b and 9a, a dressing of ammonia- salts 

 alone gives in each case, a larger yield, both of grain and straw, then 

 the 14 tons of barn-yard manure on plot 2. And recollect that 

 this plot has now received 98 tons of manure in seven years. 



" That," said the Doctor, " is certainly a very remarkable fact." 



" It is so," said the Deacon. 



"But what of it ? " asked the Squire, " even the Professor, here, 

 does not advise the use of ammonia-salts for wheat." 



* 4 That is so," said 1, "but perhaps I am mistaken. Such facts 

 as those just given, though I have been acquainted with them for 

 many years, sometimes incline me to doubt the soundness of my 

 conclusions. Still, on the whole, I think I am right." 



" We all know," said the Deacon, " that you have great respect 

 for your own opinions." 



" Never mind all that," said the Doctor, " but tell us just what 

 you think on this subject." 



" In brief," said I, " my opinion is this. We need ammonia for 

 wheat. But though ammonia-salts and nitrate of soda can often be 

 used with decided profit, yet I feel sure that we can get ammo- 

 nia or nitrogen at a less cost per Ib. by buying bran, malt roots, 

 cotton-seed cake, and other foods, and using them for the double 

 purpose of feeding stock and making manura." 



u I admit that such is the case, " said the Doctor, " but here is a 

 plot of land that has now hnd 14 tons of manure every year for 

 s?ven years, and yet there is a plot along side, dressed with am- 

 monia-salts furnishing less than half the ammonia contained in the 

 14 tons of manure, that produces a better yield of wheat." 



" That," said I, " is simply because the nitrogen in the manure 

 is not in an available condition. And the practical question is, 

 how to make the nitrogen in our manure more immediately avail- 

 able. It is one of the most important questions which agricultural 

 science is called upon to answer. Until we get more light, I fee] 



