CROP ROTATIONS 193 



park belt, but this has not yet been conclusively demon- 

 strated. Alfalfa promises much under irrigation, and 

 alsike clover also seems to offer some possibilities there. 

 (5) The lack of an intertilled crop suited to all con- 

 ditions is another difficulty. The hoed crop of Ontario, 

 the corn belt, and the northern States is corn, that of 

 England is turnips. In the warmer parts of the West 

 on warm soils corn promises much as a forage crop, but 

 in the higher altitudes and northern latitudes, par- 

 ticularly on the heavy soils, its future is not promising. 

 Turnips and other root crops can be grown where corn 

 is unsuited, but the labor cost under present (3onditions 

 is too liigh to make a large acreage a commercial suc- 

 cess. There is now no doubt but that corn will have a 

 permanent place in the cropping system of the southern 

 parts of Manitoba, Saskatchewan and Alberta, but unless 

 economic conditions change, the acreage of roots will 

 never become large enough to make this type of plant an 

 important factor as a rotation crop. The same is largely 

 true of potatoes. Rape has been grown in cultivated 

 rows for pasture in a very large way by some farmers, 

 but this practice has not developed to any extent. Witli 

 dense population and cheaper labor these crops, and sun- 

 flowers as well, may find a larger place in Western 

 rotations. 



149. Classes of Crops used in Rotations. — The crops used 

 in all good rotations may be divided into four classes: 

 (1) cash crops, (2) intertilled crops or hoed crops, (3) 

 legume crops or nitrogen gatherers and (4) grass crops. 



The chief cash crops of this country are the grain 

 crops — wheat, oats, barley and rye — and flax, although 

 hay and potatoes are also grown as money crops in some 

 places. The most important intertilled crops are corn, 



