710 IOWA DEPARTMENT OF AGRICULTURE^ 



support of the growing plant. They supply it with food dissolved in soil 

 moisture and hold it in its erect position until the ©ar appears. The 

 stalk now becomes too heavy and the brace roots make their appearance. 

 These penetrate the earth to a depth of several feet and have led to many 

 mistaken ideas in regard to cultivation of corn. They appar too late 

 in the season to be aided or injured by any system of corn culture and 

 play no important part in its cultivation. 



The first practical investigation of the root growth of corn was made 

 by Mr. J. D. Tower of Mendota, Illinois, more than thirty years ago, when 

 he conclusively proved that corn that was three to four inches high 

 had a whorl of roots five to eighteen inches in length, lying within a few 

 inches of the surface. Subsequent investigation made in all varieties of 

 soils and at all the stages of the growth during the cultivating season 

 have as conclusively proven: 



That the roots extend across the row long before the corn is laid by. 



That the length of the roots greatly exceed the height of the stalk 

 during the cultivating season. 



That the whorls of roots spring from the stalk within two inches of 

 the surface. 



That they seldom penetrate the soil below the furrow slice until cocn 

 is in the silk. 



That the usual method of corn cultivation with shovel-plows is very 

 destructive to the feeding roots. 



Prof. Kapp of the agricultural college and Prof. W. M. Hayes of the 

 university of Minnesota, made an investigation and stated that with corn 

 planted May 19, one week later, May 26, the stalks were found to be one 

 inch high and the roots average eight inches long. June 2 the stalks 

 were three and one-half inches and roots were nearly eighteen inches. 

 On the 9th, the stalks were eight and one-half inches and the roots two 

 feet. Up to this time the roots had sought their food near the surface 

 none of them having penetrated the soil to the bottom of the furrow slice. 

 With but a few exceptions they w-ere near enough the surface during 

 almost their entire length to be mangled and broken by the shovel-plow. 



On the farms in this section of the country it is no uncommon sight 

 to see a man driving the cows out of the cornfield lest a few leaves be 

 destroyed and he will immediately return to his task of butchering the 

 roots by the thousands with the shovel-plow in the honest belief that he 

 is cultivating corn. Instead of promoting the conditions' that will assist 

 the crop to grow, he not only destroys them but mutilates the work that 

 Mother Mature has already done. Not only must the soil moisture con- 

 taining plant food be brought near the surface to be warmed and purified 

 by the sun, but it must be retained there so that it will be available 

 for the young plant. It is a very well known fact that a lumpy field will 

 dry out much more quickly than a well pulverized one. There is nothing 

 to retain the evaporation in the soil moisture in the former, while the 

 latter is able to retain its moisture by the protecting layer of fine soil. 

 Harrowing, planking, rolling and pulverizing are designed to crush the 

 lumps, close the large air spaces and cover the plowed fields with a blanket 



