44 



the disks of the right-lap run about 4 inches deep. It will be seen 

 that weed seeds are not covered too deeply to germinate. By the time 

 the first cultivation has been completed from four to six weeks a 

 crop of weeds has usually made its appearance on the ground first 



one over, and it is necessary to begin the second cultivation imme- 

 iately. The disks being large and set at a considerable angle will 

 run from 5 to 6 inches deep and turn the soil and cover weeds quite 

 well. This second cultivation usually destroys a goo'd crop of weeds. 



Usually two cultivations with the right-lap is all the cultivation 

 given. However, if weeds come again, some use the right-lap the 

 third time. Others use the harrow, slicker, or some other form of 

 weeder. 



Discing before plowing is often resorted to. Just as early in 

 the spring as the ground is in good working condition the land to be 

 summer fallowed is disced. Some disc but once, while others double- 

 disc and then use a smoothing harrow. Most farmers concede that 

 the more cultivation given the better. 



There is much to commend this method. The discing and har- 

 rowing in the early spring before plowing form a loose mulch on 

 the entire area to be summer fallowed much more quickly than it 

 could be plowed. This saves a great deal of moisture, for the land 

 plowed last often becomes very dry when plowing is the first operation. 



Most weed seeds germinate best if not covered very deeply. 

 When lying on the surface of the ground, the plow often covers them 

 so deeply that they do not germinate until turned up near the sur- 

 face again by subsequent plowing. Early surface cultivation covers 

 these seeds lightly and gives them a chance to germinate before the 

 plowing is done. The plow then destroys a crop of weeds, usually 

 a heavy one. In this way practically all of the weed seed of the 

 previous season's crop may be germinated before plowing and a clean 

 surface soil turned under. 



Early surface cultivation also causes the soil to plow more easily, 

 and makes it more mellow and freer from clods. This is especially 

 noticeable where roads have been made through the fields in the fall 

 in hauling out the grain. Some farmers have formed the habit of 

 harrowing these roads in the early spring, having learned its value 

 accidentally by dragging the harrow to and from the fields. A great 

 deal of trouble is experienced in plowing land covered with heavy 

 stubble. Discing before plowing breaks the stubble down, partially 

 covers it, and gets it into such condition that the plow turns it under 

 much better than if the discing had been omitted. If the plowing 

 is not delayed too long it turns up moist, mellow earth. The im- 

 mediate use of the harrow is to settle and pulverize the soil. This 

 condition of the soil is favorable to the conservation of moisture and 

 the germination of the weed seed turned up by the plow. Later cul- 

 tivation destroys this crop of weeds and helps to retain moisture. 

 The more moisture retained in the soil while fallowing the greater 

 will be the decomposition of the stubble and other organic matter. 

 Chemical action in the soil is also favored, thus providing more min- 

 eral plant food. 



