320 DRY-FARMING 
therefore, provided with large light wheels, one for 
each furrow, which press lightly upon the soil and 
force the soil into intimate contact with the seed. 
(See Figs. 84 and 85.) The weakness of such an 
arrangement is that the soil along the drill furrows 
is left somewhat packed, which leads to a ready 
escape of the soil-moisture. Many of the drills are 
so arranged that press wheels may be used at the 
pleasure of the farmer. The seed drill is already a 
very useful implement and is rapidly being made to 
meet the special requirements of the dry-farmer. 
Corn planters are used almost exclusively on dry- 
farms where corn is the leading crop. In principle 
they are very much the same as the press drills. 
Potatoes are also generally planted by machinery. 
Wherever seeding machinery has been constructed, 
based upon the principles of dry-farming, it is a 
very advantageous adjunct to the dry-farm. 
Harvesting 
The immense areas of dry-farms are harvested 
almost wholly by the most modern machinery. For 
grain, the harvester is used almost exclusively in the 
districts where the header cannot be used, but wher- 
ever conditions permit, the header is and should be 
used. It has been explained in previous chapters 
how valuable the tall header stubble is when plowed 
under as a means of maintaining the fertility of the 
