PLANT FEEDING. 39 



most important cereal, and a wise system of farm man- 

 agement provides for the marketing of animal products 

 rather than grain products. 



The value of the manure is no slight item. Let us see 

 what it amounts to in dollars and cents. Barnyard 

 manure varies greatly in composition, as the valuable ele- 

 ments of plant food are easily lost unless proper care is 



ON MOST FARMS HOGS HAVE A PLACE. 



They furnish the home-meat supply and add many dollars to the farm re- 

 ceipts. They have paid the expenses of many boys through college and paid 

 off thousands of farm mortgages. 



taken. It contains on the average about 0.5% of nitro- 

 gen, 0.3% phosphoric acid and 0.4% of potash. 



QUESTIONS. 



1. How many pounds of nitrogen are contained in a 

 load of barnyard manure weighing one ton? How many 

 pounds of phosphoric acid? Of potash? 



2. How much are each of these elements in a ton of 

 manure worth on the basis of nitrogen at 20 cents a 



