PLANTING AND CULTIVATING 123 



cultivators were so arranged as to throw a ridge along 

 the row of corn. This is a disadvantage and has been 

 eliminated in the latest types of the disk cultivators. 



The third type, the knife, or gopher cultivators, as 

 they are sometimes called, scrape off the weeds from 

 the surface of the ground without cutting the corn 

 roots. The knives or blades do not work successfully 

 in all soils. The blade or knife does not easily pene- 

 trate the heavy clay soils, and consequently rubs over 

 many of the weeds without cutting them off. 



Ideal Cultivator — The best cultivator is that one 

 which stirs the surface of the soil thoroughly to make 

 a loose mulch, which removes the weeds completely, but 

 which does not injure the roots of the corn plant. A 

 root cut off does not reunite, or does not grow out 

 again. The ability of the plant to avail itself of plant 

 food and moisture is reduced just so much. As the 

 greater .part of the plant food available for use by the 

 plant is in the surface soil, a very great damage results 

 from cutting off the roots near the surface. Added to 

 this is the fact that any injury to the corn plant, 

 whether to the roots or stem, checks its growth and 

 must result in a decrease of yield. 



