FACTORS OF AGRICULTURAL PRODUCTION 157 



productive for less productive crops. The other is the more 

 intensive cultivation of each crop. 



Substituting heavy-yielding for light-yielding crops. As al- 

 ready indicated, much of the so-called work of reclamation 

 might be considered under the first of these heads. The substi- 

 tution of cultivated for wild grasses, the substitution of tillage 

 for pasturage, the substitution of crops requiring much cultiva- 

 tion but little land for crops requiring little cultivation but much 

 land, these are among the progressive stages in the economiz- 

 ing of land. One striking feature in this progressive economy 

 is ;he movement of the wheat belt of the United States west- 

 ward. While wheat is an important crop in the world's com- 

 merce, it is a poor one from the point of view of intensive 

 farming. It requires comparatively little work to get a moder- 

 ately good yield, but it does not respond so vigorously as do 

 certain other crops to the efforts of the farmer to increase the 

 yield. It requires more work to cultivate an acre of maize or 

 Indian corn, on the other hand, but it is possible to produce a 

 much heavier yield wherever the climate and soil are adapted to 

 its cultivation ; that is to say, this crop responds to intensive cul- 

 tivation much more vigorously than does wheat. In addition to 

 this, wheat stands transportation remarkably well. It combines 

 hign value with small bulk and can be shipped long distances 

 and sold for cash. Therefore it has happened for many years 

 thai; the world's wheat supply has come largely from regions 

 of sparse population distant from markets, where land was 

 abundant though labor was scarce. It has been a frontier crop 

 so J ar as this country is concerned, and the center of wheat pro- 

 duction has been moving westward for a great many years. As 

 the country has become more thickly settled and land conse- 

 quently less abundant relatively to the supply of labor, it has been 

 found more economical to substitute corn and other crops for 

 wheat, or to grow wheat in rotation with some of these other 



