240 TALKS ON MANUKKS. 



The produce of barley the first season (1852), was, per acre : 



On the uninanurcd plot 271 busbele 



With 6Upi.Tph()Si)haie (if lime 2^| " 



" potash, soda, and mnffnesia :.>6} " 



" " " " and superphosphate 32* " 



" 14 tons barn-yard manure Sa " 



" 200 Ihs. ammonia-salts alone 3(5J " 



" " " and superphosphate :;8i '• 



" " " and potash, soda, and magnesia 30 " 

 " " " and superphosphate, potash, 



soda, and magnesia 40 J " 



" 400 lbs. ammonia-salts alone 44i " 



The 200 lbs. of ammonia-salts contain 50 lbs. of ammonia:=41 

 lbs. nitrogen. 



It will be seen that this 50 lbs. of ammonia alone, on plot la. 

 gives an increase of nearly 10 bu.'^bcls per acre, or to be more accu- 

 rate, it gives an inerea.so over the nnmantircd plot of 503 Ib.s. of 

 grain, and 32!) lbs. of straw , while double the quantity of ammonia 

 on plot la.a., gives an increase of 17^ bushels per acre — or an in- 

 crease of 901 lbs. of grain, and 1,144 lbs. of straw. 



"Put that fact in separate lines, side by side," said the Deacon, 

 " so that we can see it." 



Total 

 Grain Straw Produce. 



50 lbs. of ammonia gives an increase of 503 lbs. 704 lbs. 1207 Ibe. 



100 " " " " " " " .... l»01 " 1144 " 2045 " 

 The first 50 lbs. of ammonia gives an in- 

 crease of .. .. 503 " 704 " 1207 " 



The second 50 Ibe. of ammonia gives an in- 

 crease of 398 " 540 " 738 " 



" That shows," said the Deacon, " that a dressing of 50 lbs. per 

 acre pays better than a dressing of 100 lbs. per acre. I wish Mr. 

 Lawes had sown 75 lbs. on one plot." 



I wish so, too, but it is quite probable that in our climate. 50 

 lbs. of .available ammonia per acre is all that it will usu.ally be 

 profitable to apply per acre to the barley crop. It is equal to a 

 dressing of 500 lbs. guaranteed Peruvian guano, or 275 lbs. nitrate 

 of soda. — " Or to how much manure ? " asked the Deacon. 



To about 5 tons of average stable-manure, or say three tons of 

 good, well-rotted manure from grain-fed animals. 



" And yet," said the Deacon, " Mr. Lawes put on 14 tons of yard 

 manure per acre, and the yield of barley was not as much as from 

 the 50 lbs. of ammonia alone. How do you account for that?" 



Simply because the ammonia in the manure is not ammonia. It 

 is what the chemists used to call " potential ammonia." A good 

 deal of it is in tlie form of undigested straw and bay. The nitro- 

 genous matter of the food wliich has been digested by the animal 



