INTRODUCTION 



without the use of an undue portion of the time. 

 The stores of plant-food throughout all the soil 

 are more surely reached by a variety of plants, 

 differing in their habits of root-growth. The in- 

 jury from disease and insects is kept down to a 

 minimum. There is better distribution of the 

 labor required by the farm, and neglect of crops 

 at critical times is escaped. The maintenance of 

 fertility is dependent much upon the use of a 

 legume that will furnish nitrogen from the air. 

 A permanently successful agriculture in our coun- 

 try must be based upon the use of legumes, and 

 crop-rotations would be demanded for this reason 

 alone if none other existed. 



Fertilizers. When a crop is fed to livestock, 

 and all the manure is returned to the land that 

 produced the crop without loss by leaching or 

 fermentation, there is a return to the land of four 

 fifths of the fertility, and a good form of organic 

 matter is supplied. A portion of the crops cannot 

 be fed upon the farm, or otherwise the human 

 race would have only animal products for food. 

 The welfare of the people demands that a vast 

 amount of the soil's crops be sold from the farms 

 producing them. This brings about a dependence 

 upon the natural stores of plant-food in the soil, 



[9] 



