222 BOARD OF AGRICULTURE. 



not contain deficient plant food, but in some way acts on the soil so 

 AS to hasten the change of unavailable plant food in the soil into 

 available, that is, they increase the natural capacity of the soil. 

 Xiime, gypsum, salt, etc., so far as they have any action, beloog to 

 this class ; others, like ashes, and especially leached ashes, are both 

 direct (furnishing plant food) and indirect. 



SOURCES OF PLANT FOOD. 



"We are now in position to inquire about the sources of plant food, 

 and for our present purposes only the deficient plant food will 

 receive attention, that is, nitrogen, phosphoric acid and potash. 



Farm yard manure is the chief source of plant food in mixed 

 agriculture. It consists of two parts, solid and liquid. The solid 

 portion represents that part of the food which is not digested in the 

 animal system, while the liquid manure contains the waste products 

 of the digested food. 



Ordinary farm yard manure, from cows, oxen, and growing 

 cattle, has the following average composition. The composition of 

 horse manure, sheep manure, and hog manure, is also given : 



In order that we may be able to know the actual amount of plant 

 food applied to an acre, in any given case, I will give the best 

 available figures showing the weight of a cord of manure. 



Manure from neat cattle and sheep will weigh not far from 8,000 

 pounds, or four tons per cord ; horse manure, 6,000 pounds, or 

 three tons ; while hog manure, as usually found, will probably 

 weigh more than either of those given. As manure is ordinarily 

 drawn in a cart holding fort}' bushels it will require three loads, 

 without treading to make a cord. The number of cords and tons 

 may thus be estimated with considerable accuracy. In the following 

 table I have figured the actual plant food per ton, per cord, and 

 per load of one-third cord : 



