THE SOIL AS AN ASSET 221 



of turnips exercised the same effect, as these 

 roots are highly carbonaceous. This explained 

 one of the benefits of plowing under "swedes," 

 a practice almost as old as agriculture it- 

 self. 



"When neither clover is grown, nor the roots 

 of turnips put back," says Doctor Hall in 

 commenting on his experiments, "the soil is 

 losing nitrogen; when both take place during 

 a rotation, the average removals from the soil 

 become as high as 35 bushels of wheat, 34 

 bushels of barley and 2 tons of clover hay, yet 

 the soil is gaining in fertility though no ex- 

 traneous nitrogen is being introduced." 



Speaking of the farming of the future in 

 the light of this discovery, Doctor Hall is led 

 to say: 



"The only way is to bring the flora and 

 micro-fauna of the soil under control. Partial 

 sterilization effects this; such antiseptics as 

 chloroform, toluene, etc., eliminate certain 

 organisms which check the useful bacteria. 

 Heating to boiling for two hours doubles pro- 

 ductivity and is practical in greenhouses. 



"The problem of the future is to domesticate 

 the unseen flora and fauna of the soil, the 

 useful races to be encouraged^ the noxious 

 races suppressed" 



