LEGUMES 53 



legume. If this crop is plowed under, nitrogen is 

 added to the soil, which is consequently enriched and 

 at the same time improved in texture, especially if it 

 be a clayey soil. This is the secret of clover growing 

 on the farm. It is the common practice among farm- 

 ers to cut the first crop of clover for hay and plow 

 under the second crop. Thus the clover is made to 

 serve a double purpose first furnishing food for stock, 

 and next a supply of nitrogen for the soil. 



Free Bulletins, U. S. Dept. of Agriculture. 

 Farmers' Bulletins. 



No. 89. Cowpeas. 



No. 194. Alfalfa Seed. 



No. 214. Beneficial Bacteria for Leguminous Crops. 



No. 215. Alfalfa Growing. 



Problems. 



1. How does clover compare with other kinds of 

 hay in the amount of nitrogen it contains ? Phosphoric 

 acid ? Potash ? 



2. If two tons of hay per acre is an average yield, 

 how much of each fertilizer is removed yearly with 

 this crop from 8 acres of ground. 



3. Which kind of hay makes the richest manure? 

 Why? 



4. How much more of nitrogen in a crop of 25 

 acres of clover hay, yielding 3 tons per acre, than in 

 the same number of acres of mixed hay yielding 2 

 tons per acre? Where does this extra nitrogen come 

 from 



