164 BOARD OF AGRICULTURE. 



number of plots of land with different crops and different 

 fertilizers, will get hold of a great many facts and find a 

 great many questions coming up which it would be exceed- 

 ingly interesting to discuss. This is what Mr. Lawes has 

 done. He has shown that on his land, in order to get a large 

 crop of wheat, he must use a great deal of one kind of ma- 

 nure. I mentioned yesterday that he got 16 bushels of wheat 

 to the acre, for twenty-seven years, in unbroken succession, 

 on land to which he applied no manure whatever ; that by the 

 use of 14 tons of stable manure per acre, applied annually, 

 he was able to get 36 bushels of wheat. By using all the 

 elements of our fertilizers, with the single exception of nitro- 

 gen, applying phosphates, sulphates, and nitrates of lime, mag- 

 nesia, potash, and soda, all the fertilizing matters which are 

 found in ashes, in guano, or in stable dung, nitrogen com- 

 pounds excepted, he raised the crop to barely 25 bushels; but 

 when, to one good dose of these materials, he added annually 

 400 lbs. of salts of ammonia, or nitrate of soda, the yield went 

 up to 36 bushels and held at that point for years. This differ- 

 ence between 25 and 36 was unquestionably due to the nitrogen 

 of the nitrate of soda or salts of ammonia. If the facts ad- 

 mit of any other inference, I do not understand the logic 

 which can make it. 



Let us compare the quantities of nitrogen in those two ap- 

 plications. In the salts of ammonia, there were about 80 lbs. 

 of nitrogen ; in the barn-yard manure, Mr. Lawes says 200 

 lbs. ; but there arc usually nearer 300 lbs. of nitrogen in strong- 

 stable manure. It would thus appear that there must be a 

 great loss of nitrogen, and the wheat crop has got the repute, 

 among some writers, of wasting a great deal of nitrogen in its 

 growth. 



On another plot of land, where Mr. Lawes raised barley, 

 he applied 200 lbs. of ammonia-salts, which contained 40 lbs. 

 of nitrogen, and raised 48 bushels to the acre. When he 

 doubled his dose, and put on 80 lbs. of nitrogen, his grain 

 was so heavy that it lodged and failed to ripen, and the crop 

 was spoiled. Without the addition of any fertilizer, the soil 

 gave him considerably less than half that amount. 



