126 BOARD OF AGRICULTURE. 



stover. But there is one other advantage to which I would 

 like to call your attention ; and that is, that, by cultivating 

 the land, we aerate it, and we draw from the air — that great 

 reservoir of fertility — a very large amount, and the soil 

 absorbs it. Old Jethro Tull used to say, that, if we would 

 only cultivate our lands sufficiently, we could get along 

 without any manure whatever. He carried his theory 

 undoubtedly too far. But from my observation I am satis- 

 fied that we can get along with very much less manure, if 

 we only cultivate our land thoroughly, and pulverize it so 

 that the air will penetrate it. It will not only have more 

 moisture, but it will have more air. There is more fertility 

 in the air than we think for. Every time we burn any 

 thing, all the organic part goes into the air. Every kind of 

 vegetable that decays on the surface, every kind of leaf that 

 decays on the surface of the soil, the organic part goes into 

 the air, and from the air it must come back ; and we want 

 to keep our soil in such condition that it can absorb this 

 fertility from the air. 



If Dr. Sturtevant is in the house, I would like to have 

 him give us his opinion upon this point, — the cultivation of 

 our soil by making it an absorbent of atmospheric fertilizers. 



Dr. Sturtevant. All the carbonic acid in a plant, the 

 great bulk of the plant, — that which forms the woody fibre, 

 the starch, the sugar, and enters into almost every part of 

 the plant, — passes to the plant through the green coloring- 

 matter of the leaf; and in our agricultural plants we can 

 lay it down as a rule that no other substance is absorbed hy 

 the leaf except carbonic acid. 



Mr. Hyde. I agree with you ; but I think the soil will 

 absorb a great amount more if we only have it porous, so 

 that air can penetrate it. The nitrogen of the air comes 

 down, the ammonia comes down, and is absorbed by the soil. 

 Is not that so ? 



Dr. Sturtevaxt. The question of its absorption, I think, 

 must be put under advisement. I know of no case where it 

 has been really proved that the soil absorbs much fertilizing 

 material from the air, or that the plant receives much fertil- 

 izing material directly from the atmosphere, with the excep- 

 tion which I just stated. But this whole question of the 

 formation of nitrogen in the soil is a very obscure one. It 



