262 



SOILS 



served. It has been determined that a cow produces four- 

 teen tons of manure per year; but since there is always 

 some waste, we will say that ten tons only are recovered, 

 each ton of which is worth $2.95 per ton, as actual crop- 

 producing experiments have shown to be the case. On 

 this basis of valuation, the fertility from the fifteen cows 

 will be worth, annually, $442.50, or $8,850 for a twenty- 

 year period. 



Besides the value of the fertility, there is to be added 

 to the gross receipts of the farm $18,720, received from 



TWO KINDS OF FARMING 



Grain farming forces plant food from the soil, but the dairy cow maintains the 

 fertility of the land 



the sale of butter fat, and $3,600, the value of the skim 

 milk ; and these have paid for feed, and labor, and some 

 is left for profit. If the manure has been cared for and 

 distributed properly over the soil, the fifteen cows in 

 twenty years have replaced the $8,850 worth of soil fer- 

 tility that was removed from the soil by the twenty crops 

 of wheat. Hence, fifteen cows are able to balance the soil 

 fertility that is removed in growing one hundred acres of 

 wheat. 



Combined with dairying, wheat growing can be carried 

 on indefinitely, without the loss of fertility. In other 

 words, interest and not capital is withdrawn in this farm- 



