FOURTH ANNUAL YEAR BOOK — PART II. 133 



ing the surface of the drift deposits into a mantle of humus as rich in the 

 elements of plant growth as tne famed valley of the Ni'e. There is no con- 

 tinent on earth that contains so large an area of exceedingly fertile lands as 

 we have in the great corn belt of America. 



CLIMATE THE CHIEF FACTOR. 



In crop production the prime factors are fertility of soil and a congenial 

 climate; and climate is the chief factor. There are millions of acres in this 

 country, now comparatively worthless though containing abundant supplies 

 of fertility, the one thing lacking being a favorable climate. Nothing can 

 fully compensate for the lack of ample moisture in the growing season, as 

 only a small part of any arid region may be made productive by irrigation. 

 And prevalent low temperature, or frequent occurrence of frosts in the crop 

 growing season, will render nugatory the most fertile soil and abundant 

 rainfall. The true tests of climatic excellence are found in the tables of mean 

 temperature and precipitation, and the average number of days between 

 killing frosts in the crop season. Iowa has attained its present unrivaled 

 position as an agricultural state by its heritage of vast wealth of soil and its 

 generally favorable climate. In attestation of that claim the appended 

 tables of annual crop yield may be cited. There has been nothing near a 

 total failure of the staple farm crops in the worst season experienced since 

 its settlement by civilized people. There have been lean and fat years, but 

 the products of the leanest season would be fatness to the people of less 

 favored regions. This is the result of the fine texture and great depth of 

 soil, whereby it is able to endure the greatest extremes in form of wet or 

 dry seasons. 



GENERAL CLIMATIC FEATURES. 



Situated near the geographical center of the United States, too far inland 

 to receive the equalizing thermal effects of winds blowing directly from the 

 oceans, the climate of Iowa is strictly continental in type. This implies a 

 very wide range in temperature, winters of considerable severity, summers 

 of almost tropical heat, and a large percentage of sunshine as compared with 

 insular regions. As there are no mountain ranges, nor considerable differ- 

 ences in the altitude of the several sections, the climate of the state is quite 

 homogenous, with only such variations of temperature and rainfall as result 

 from latitude and location with reference to the pathway of the cyclones 

 which traverse the continent. Despite its remoteness from the oceans, the 

 seasonal constants of temperature, humidity and precipitation afford a guar- 

 anty of ample production in the future as in the past. In fact, it is the best 

 watered and most productive mid-continent region known on earth. Its 

 worst droughts and seasons of floods have never been famine breeders. 



Climate is the product of certain elements and properties of the atmos- 

 phere, and physical features of the earth's surface. The sun's energy pro- 

 duces in the air and earth the threefold forms of force termed light, heat and 

 electricity, and causes the varied phenomena of evaporation and precipita- 

 tion. The climate of this section differs from that of other midland regions 

 bceau'^e of material differences in the topographic features of the western 

 continent. The great mountain ranges that gridiron the western third of 

 the continent, stretching from the Arctic Sea to the isthmus and enclosing 

 numerous valleys of the semi-arid or desert type, effectually cutting off the 



