158 BOARD OF AGRICULTURE. 



the soil ; but the practical farmer has found out that there is 

 some disagreement between this analysis of the chemist and his 

 own practical results. He finds that wheat exhausts his soil 

 more than the analysis indicates, while his cabbages, turnips 

 and some other things which he raises are not so exhausting as 

 the chemist represents them to be. He cannot reconcile these 

 facts. The vegetable physiologist comes forward and explains 

 in this manner : That these plants, during their period of 

 growth, are large consumers — exhausters, so to speak — not of 

 the mineral elements of the soil, (the chemist is correct, so far 

 as the exhaustion of the mineral elements is concerned,) but 

 they are large consumers of the nitrogenous elements which 

 are demanded by vegetable growth, which they do not show in 

 their matured product, and wheat is considered at the head of 

 that list. The other grains produce the same results, in a cer- 

 tain degree, but wheat is deemed the highest form of food for 

 man which we raise from the ground ; the most perfect one, 

 and we find it, in that respect, the most exhaustive. Therefore, 

 in reasoning upon this subject of the rotation of crops, we must 

 take into account not only the exhaustion of the mineral ele- 

 ments of the soil, resulting from the entire produce of the 

 land, but also the exhaustive effect upon the land in using up 

 the nitrogenous elements of fertility. 



Still another point. The physical condition in which a crop 

 leaves the land is an important consideration. Some lands are 

 benefited by being left in a more compact form ; some lands are 

 benefited by being left in a lighter form. Some crops have a 

 tendency to make the land light, others to make it more heavy. 

 Then, again, some crops so affect other crops that it was sup- 

 posed by vegetable physiologists, for a long time, that they ex- 

 creted some particular element that did not allow the other 

 crops to follow with success after them. This has been noticed 

 by practical men, and it is an element which must be taken into 

 account. The fact is, that the proper rotation of crops is a 

 matter which, like a great many others that we thought we had 

 settled a few years ago, has been brought into a great deal of 

 doubt by the recent discoveries of science. 



Prof. Chadbourne. I can hardly speak too highly of the very 

 able address of Prof. Stockbridge ; but I wish to say to the gen- 

 tleman who has just sat down, that, so far from the West being 



