DAIRY AND SEED IMPROVEMENT MEETINGS. 293 



Butter 08 



Cream 53 



Eggs 1.77 



Whole milk 407 



Meat 461 



Potatoes 10.53 



Oats 24.48 



Timothy hay 32.13 



Straw 5740 



Clover hay 66.62 



Average prices over a series of years were used in these 

 calculations. Of all classes of farming we see that dairying is 

 the least exhaustive, except in the sale of whole milk, of plant 

 food. And if concentrates are purchased and fed, in many 

 cases the supply of plant food in the soil may be increased. 



Let us consider the reasons for the effect that the sale of 

 different products has upon the plant food problem. Under 

 average conditions, about So^c of the plant food in the feed is 

 recovered in the manure, — that is 80% of the nitrogen, phos- 

 phoric acid, and potash in the feed is excreted by the animal 

 in the manure. This amount is less in young growing animals 

 and animals giving milk, and more in mature animals. 



We can see, however, that the value of manure would depend 

 directly upon the feed, and the man purchasing concentrates 

 and other rich feeds can expect his animals to produce more 

 valuable manure than the man who is feeding less concentrated 

 feeds. However, the fact that 80% of the plant food is recov- 

 ered in the manure is of more importance. 



It is figured that the fertility of the soil would be kept up, 

 if crops were all fed and the manure returned to the fields 

 without loss. That made available yearly in the soil would 

 make up for the twenty per cent retained in the bodies of the 

 animals. This, of course, would not continue indefinitely, and 

 usually the phosphoric acid would be the first element to become 

 lacking, if such a system were followed. It is doubtful if, in a 

 region having cool summers, manure can be depended upon 

 entirely. The plant food in the manure must be made avail- 

 able by the soil factors referred to previously. These are 

 •considerably more active in summer than in the early spring. 



