Cereal Farming 10 harvested. Not much, to be sure, is raised in the western half of the United States, where there is too little rainfall for it and the high plateaus are too cold, especially during the nights in summer. A good deal is raised in the Appalachian Mountain states, though the land is rugged and the soil coarse. But even there the crop is meager compared with the region of the greatest production, where the con- ditions for corn are so favorable that in summer it is difficult to get out of sight of growing corn. This region, as is seen in Figure 31, extends from eastern Nebraska across Iowa, Illinois, and Indiana to western Ohio. It is called the American corn belt. On the rolling prairies of the corn belt it is possible to use machin- ery almost as freely as in raising wheat. The relief is so gentle that almost every acre can be planted. The soil is deep, fertile, and so free from stones that cultivators, which root out the weeds, can slide smoothly through it between the rows of corn. The lemperature is such that there is a long growing season without frosts. Both the days and the nights are warm in summer, and the great heat of midsummer makes the corn grow wonderfully. Although a good amount of rain falls, it generally comes in brief thunder showers and the sun is little clouded. Corn in other lands. Most of the conditions that favor corn grow- ing prevail in Rumania, Hungary, Mexico, and Argentina, and in those regions corn is an important crop (Fig. 39). In Argentina, especially, corn has been rapidly increasing in importance, until now the crop is larger than that of wheat. Corn cannot be grown in Canada — except in southern Ontario—or in northern Europe, be- cause these northern regicns 10 not have summers that are long enough or warm enc:z> Tov have less than five months free from frost. UNITED STA™ RICE ACREA{: 1919 £ACH DOT REPRESENTS 2000 ACRES Fic. 33. In eastern Texas, along the Gulf coast, and in the Mississippi river lands of Arkansas are found level, swampy tracts of good soil within the belt of high temperature that rice needs. In the inland valleys of California, where soil, surface, and temperature are suitable for the up- land varieties. rice is now cultivated successfully on irrigated land.