336 Singing Valleys 



com." Sometimes they changed it to "God made corn for this 

 country/' It didn't matter which way you put it. It was true 

 both ways. 



Here were one hundred and forty million acres, more than 

 half of which was in plow-land. Forty-five million acres of this 

 in corn. This represents 65 percent of all the corn grown in 

 the country. 



Three factors necessary to corn-growing meet in the corn 

 belt. These are a deep, rich, well-drained soil, abundant rain- 

 fall and hot summer nights. All plants derive their nourish- 

 ment from two sources, the air and the soil. The first supplies 

 oxygen and carbon dioxide which the plant takes in through 

 leaves and stalk. Meanwhile the roots feel around through the 

 soil in search of the ten chemical elements which are vitally 

 necessary to every plant's growth. These are nitrogen, phos- 

 phorus, potassium, calcium, sulphur, magnesium, sodium, 

 iron, chlorine and silicon. The first three of these are most 

 in demand, but each one of the ten elements is essential to 

 the development of some part of the plant. Nor can any 

 excess of any one element make up for the deficiency of an- 

 other. There is a wide difference in the amount of each that 

 is required by each plant. To plant potatoes, for instance, in a 

 soil which is rich in nitrogen and phosphoric acid, but low 

 in potassium, is to court famine. Nitrogen, potassium and 

 calcium are needed to form the larger part of the corn's tissues. 

 The last does valuable work in hardening the stalk to with- 

 stand drought. Calcium is a characteristic constituent of the 

 limestone soils of the corn belt. 



The clovers, vetches and peas which are gross nitrogen feed- 

 ers have developed the ability to draw nitrogen from the air as 

 well as from the soil. Beads of the chemical are stored on the 

 plants' roots. This makes them valuable as "green manure" to 

 enrich the fields for corn to follow the next year. The corn is 

 greedy. When young it requires plenty of easily available food. 



Research in soil and plant chemistry is a relatively new 

 science. Its findings and warnings are still new voices to many 



