MICROBES AS ENRICHERS OF SOIL 115 



dissolution by microbes the soil is enriched and the 

 round earth kept clean and sweet for the dwelling 

 of man and beast. 



Fourth and finally, the soil is made more produc- 

 tive by fertilizers specially prepared by the farmer. 

 Most important among these are the compost 

 and barnyard manure. But every farmer knows 

 that neither of these fertilizers, in its green state, 

 is fit for use. They must first undergo a ripening 

 process, and this change is effected wholly by mi- 

 crobes. Microbes attack the green fertilizer and 

 by their life processes reduce it to nitrates. In 

 this condition, applied to the soil, it becomes a 

 most excellent plant food. 



The service rendered, therefore, in all these va- 

 rious ways by these invisible friends as enrichers 

 of the soil, is indeed inestimable. 



