48 THE HANDBOOK FOR PEACTICAL FARMERS 



Relation of climate to the production of corn. — Under favor- 

 able conditions of climate and soil, corn is capable of very high 

 yields. Yields of two hundred to two hundred and fifty-five 

 bushels per acre have been recorded where heavy applications 

 of manure and fertilizer were made and where the soil and cli- 

 matic factors w^ere favorable. Regardless of the ability of corn 

 to yield, the average for the United States is about twenty-six 

 bushels per acre. 



The best climate for corn production is one with abundant 

 sunshine, warm days and nights, and plenty of rainfall. Regions 

 with favorable temperatures and rainfall mth frequent cloudy 

 days often cause a retarded growth and reduced yield ; likewise, 

 regions with warm da^^s and favorable sunshine and rainfall 

 conditions but with cool nights are not ideal for corn produc- 

 tion. Rainfall is also a limiting factor in a large portion of the 

 United States, especially in regions of less than twenty inches. 

 A heavy crop of corn requires an enormous amount of water. 

 In the production of one bushel of corn from eighteen to twenty 

 tons of water is taken up by the roots of the plant and lost by 

 transpiration from the leaves. The time when an abundant 

 supply of water is required is during the three months of the 

 growing season, June, July and August. If other conditions 

 are favorable, a rainfall of twelve to fourteen inches during this 

 period, if well distributed, will insure a good crop. 



Adaptation. — Corn originated in a warm, humid climate with 

 a long growing season, but has become adapted to regions vary- 

 ing widely in these climatic factors. Corn varieties vary in the 

 time required for maturity from ninety to two hundred days; 

 they likewise vary in their ability to yield in dry climates, at 

 high elevations, etc. Although corn is grown to a greater or less 

 extent in this wide range of climatic conditions, the greatest 

 production is restricted to a definite area with a mean smnmer 

 temperature of seventy degrees F. to eighty degrees F., a mean 

 night temperature of about fifty-eight degrees, a season of one 

 hundred and forty days or more without frost and an annual 

 summer rainfall of at least eight inches with a total of twenty- 

 five to fifty inches. 



Relation of soils to the production of corn. — The best corn 

 soils are deep, warm, dark-colored loams or silt loams with a 

 large amount of organic matter and available nitrogen. These 

 soils are most often found in the river bottoms of the Mississippi 

 River basin. However, corn production is not limited to such 

 soils or else there would be only a small acreage in the United 



