116 AGRICULTURE. 



II. For Green Manuring, 



or plowing under for fertilizing, the leguminous 

 plants, such as the red, white, or the crimson 

 clover, cow-peas, and soy-beans, are of more 

 value than other crops, since they are compara- 

 tively rich in phosphorus and potash, and fur- 

 nish a supply of nitrogenous compounds, the 

 nitrogen of which is obtained, through their re- 

 lation with certain bacteria, from the air, thus 

 not impoverishing the soil. Green manuring 

 with leguminous plants, while very effective, can 

 hardly be afforded, except for the purpose of 

 building up worn-out, or poor, soil, since legu- 

 minous hay is so valuable as feed (Chapter I.). 

 At the same time more than half of the fertiliz- 

 ing elements may be given back to the soil in 

 stable manure if rightly cared for and applied. 



C. LEGUMINOUS PLANTS AS FOOD. 



I. Digestible Crude Protein 



is absolutely essential to the upbuilding of the 

 tissues of the animal body in repairing broken- 

 down tissues. It has been proven by repeated 

 experiments that a ration which contains a large 

 per cent, of digestible crude protein gives the 

 best results for the least money in the produc- 

 tion of milk, and in contributing to a vigorous 

 and healthful growth of the young. It has been 

 ascertained by analysis, as shown by the follow- 

 ing table of comparisons, that the per cent, of 



