34 THE WHEAT INDUSTRY 



hoe drill consists of a series of small shovels which 

 open the ground to permit a stream of wheat to be 

 introduced just back of them so that the soil 

 settles back in place covering the seed. This 

 form of drill is well adapted to heavy soils which 

 are naturally inclined to pack closely. For more 

 friable soils the furrow is usually opened by means 

 of a runner or disc, either single or double. The 

 seed is introduced just behind the furrow opener 

 and the furrow is closed by a wheel which follows 

 and compacts the soil. The pressure is applied 

 either by a spring on the wheel or is caused by 

 the weight of the machine resting on the rear 

 wheels (Fig. 20). These machines are known 

 as press drills and are extensively used in the 

 districts of sandy or friable soils. They have 

 proved of great value in furnishing carefully pre- 

 pared, compacted seed beds for a large part of the 

 great wheat-producing area of the West. They 

 seem to be the kind best adapted to the soils in 

 which wheat thrives best. 



Time of Sowing. - The best time for sowing 

 wheat varies with so many factors that it is 

 difficult to state any general rule. For winter 

 wheat districts, early seeding prevails in the 

 northern parts ; late, in the southern. The sow- 

 ing must be early enough to give time for a fairly 

 sturdy growth, otherwise the wheat is unable to 

 withstand winter hardships. There is also a dan- 



