66 PLOWING 
green manuring crop will send their roots much below 
the plowed surface; that the deeper the seed bed, the 
greater its capacity for root growth, holding moisture 
and compounding plant food; that so long as the proper 
plow is used in plowing no danger can result in deep 
plowing, but rather will your crop yields be materially 
increased. 
Tull, an agricultural writer, claims that by thoroughly 
pulverizing the soil its fertility can be permanently 
maintained; that by repeated plowing he produced 
twelve successive large crops of wheat on the same land 
without manure. 
Supplement Tull’s system of frequent plowing and 
pulverizing the soil with deep plowing and the turning 
under of plenty of organic matter and you have the 
secret of building and keeping up the fertility of the 
soil. 
