Farm Manure. 

 Lasting Effect of Manure. 



141 



The table shows that the effect of the manure was perceptible 

 in yield for at least 20 years after the last application. In fact 

 the value of barn yard manure cannot be estimated on the basis 

 of the plant food it contains alone. It has a greater value than 

 that because of its improvement on the physical conditions of the 

 soil and the increased fermentations which result from its ap- 

 plication. It is always a safe fertilizer for the inexperienced 

 farmer, as there is little danger of lasting injury from its use, 

 while it is possible to use commercial fertilizers in such a way 

 as to make the soil poorer after their use than it was before. 



Effect of style of farming on fertility. Prominent authorities 

 in agriculture believe that in a system of strictly animal hus- 

 bandry, where nothing is sold from the farm except animals or 

 animal products, and all the manure properly saved and utilized, 

 the fertility of the land may be maintained indefinitely without 

 the purchase of commercial fertilizers. It should be remembered 

 that a positive balance of plant food could not be maintained in 

 this way unless additional feeding materials were purchased and 

 fed on the farm. This is due to the 20 per cent loss of fertilizing 

 materials contained in the growing animals and milk produced. 

 While there may be large stores of potential plant food in the 

 soil which could make up the 20 per cent yearly deficit and main- 

 tain average crop production, nevertheless, a permanent agri- 

 culture could not be founded on such practice. 



In systems of animal husbandry it is the rule to purchase ad- 



