170 BOARD OF AGRICULTURE. 



or conversion of ammonia into' nitrates, goes on, and the ni- 

 trates are freely soluble and wash out of the soil. Then wo 

 know that the roots of the plant cannot come into contact 

 with the whole of the soil, so that we should not expect that 

 all the available nitrogen there would be taken up. The 

 figures show that from seventy to eighty pounds is sufficient, 

 provided it is in a form and in a position in which the plant 

 can appropriate it. In stable manure we appear to waste a 

 considerable quantity simply because it is not present in a 

 form in which the plant can use it. 



Now, stable manure, wdien it is put into the soil, may be 

 compared with clover roots or any other vegetable matter put 

 into the soil. Stable manure consists very largely of vege. 

 table matter which has passed through animals, and of 

 more or less litter wdiich we mix with it. There is a small 

 portion of the nitrogen of the manure actually formed into 

 these ammonia salts which Mr. Lawes applied, but most of 

 the nitrogen, in order to be used by the plant, must be trans- 

 formed, must pass into some other state than that in which it 

 exists in the manure itself; must probably either be convert- 

 ed into ammonia or nitrates. 



Mr. Lyman. Suppose the case that I wish to use all the 

 liquids of my stock, and absorb it all, and do not pay so 

 much attention to the coarser manure. What, in your judg- 

 ment, is the relative value of the one placed by the side of 

 the other? This question is being agitated extensively. 



Prof. Johnson. That depends somewhat upon the food 

 which the animals have. If they are kept upon low rations 

 the liquids would be the best. But if they are supplied with rich 

 food, grain, meal or oil-cake, that indeed increases the value 

 of the liquids, but increases more, relatively, the value of the 

 solids, because you cannot get into the circulation of the ani- 

 mal beyond a certain amount of nutritive matter ; but you 

 can run through the intestinal canal much more material 

 which is only partially digested, and so the value of the solid 

 manures, as compared with the liquids, is increased by in- 

 creasing the richness of the food. 



When oxen or other herbivorous animals are kept on ra- 



