THE CLOVERS 



Fertility Value. Attempts have been made 

 to express the actual value of a good clover crop 

 to the soil in terms of money. The number of 

 pounds of matter in the roots and stubble has 

 been determined, and analyses show the percent- 

 age of nitrogen, phosphoric acid, and potash 

 contained. The two crops harvested in the second 

 year of its growth likewise have their content of 

 plant-food determined. If the total amounts of 

 nitrogen, phosphoric acid, and potash have their 

 values fixed by multiplying the number of pounds 

 of each ingredient of plant-food by their respec- 

 tive market values, as is the practice in the case 

 of commercial fertilizers, a total valuation may 

 be placed upon the clover, roots and top, as a 

 fertilizer. Such valuation is so misleading that 

 it affords no true guidance to the farmer. In 

 the first place, the phosphoric acid and potash 

 were taken out of the soil, and while some part of 

 these materials may have been without immedi- 

 ate value to another crop until used by the clover, 

 no one knows how much value was given to them 

 by the action of the clover. Again, no one knows 

 what percentage of the nitrogen in the clover came 

 from the air, and how much was drawn from the 

 soil's stores. The proportion varies with the 

 E [49] 



