MICROBES AS ENRICHERS OF SOIL 113 



powdered form. Make it abundant enough to sow 

 with some seed, say wheat, a large tract of the bar- 

 ren land. The cost should not exceed one dollar 

 twenty-five cents per acre. Prepare the soil, mix 

 the powder with the seed, and sow. As soon as the 

 microbes in the culture find a congenial environ- 

 ment in the soil, they begin to grow and multiply 

 with great rapidity. By their life processes they 

 transfer nitrogen from the air to the soil. The 

 fine rootlets of the sprouting seed now find abun- 

 dant nitrogenous food in the soil. The result is a 

 good crop of wheat. 



Experiments have been made along this line, 

 especially in Europe, and with good success. It is 

 one method of enriching the soil by the culture of 

 microbes, a bright promise for the future. 



Another method is by cultivating the Legumes, 

 This family of plants numbers 7,000 species. 

 Among them are the pea, the bean, and the clover. 

 The clover is the most prominent, and. probably the 

 most profitable to cultivate. Its roots, in connec- 

 tion with certain other species of soil microbes, 

 have the faculty of extracting nitrogen from the 

 air and fixing it in the soil. On the roots are 

 formed minute spherical bunches. By bacteriolog- 

 ical examination these bunches are found to be no 

 more or less than clusters of bacteria, or microbes. 

 Growing and thriving with the roots, these beings 

 extract nitrogen from the air and fix it in the soil. 

 Thus the soil becomes richer. The roots of the 

 clover subsist on this nitrogenous matter, and thus 



