CLIMATIC FACTORS 



67 



Professor Hunt/ at the Illinois Agricultural Experiment 

 Station, grew 18 plats of corn which yielded 32 bushels 

 per acre. The next year, and on the same plats and with 

 the same varieties of corn, the yield was 94 bushels per 

 acre. The rainfall from May to September was 13 inches 

 the first season and 22.5 inches the second season. 



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Fig. 25. — Rainfall of June, July, and August, and yield of corn per acre. 

 (Year Book, U.S. Dept. Agr., 1903.) 



Average yields of corn 1888 to 1902. 



Average rainfall for June, July, and August. 



The seasonal rainfall and its distribution is the most 

 important climatic factor in corn production. With suffi- 

 cient rainfall, properly distributed, it is probable that the 

 present 3deld of corn would be increased 50 to 100 per cent. 

 We cannot control the rainfall or its distribution during 

 the season, therefore farm practice must make the best 

 use of rainfall as it comes. The present rainfall is suffi- 

 cient for two to three times the present yield, if it is con- 

 served and the soil is in the most fertile condition. 



' Hunt, T. F. Cereals in America, p. 207. 



