196 THE OLIVER PLOW BOOK 



A disk plow can be set to work in any type of soil but 

 wherever a mouldboard plow operates it is better to use 

 a mouldboard plow because it does a superior quality of 

 pulverizing. The disk plow will not turn so good a 

 furrow in a light sandy soil as a mouldboard plow will, 

 neither does it work so well as a mouldboard plow in 

 plowing weedy stubblefields or grasslands where mould- 

 board plows scour. 



Dry plowing has been interesting farmers a great deal. 

 The conclusion reached from the plowing of dry ground 

 in the hot summer is that the evaporation of moisture 

 from the sub-soil is greatly lessened and the land derives 

 much greater benefit from driving rains. That is, more 

 of the rainfall sinks into the ground. The weeds also 

 get an earlier start, providing there is sufficient moisture 

 in the ground, thus giving a better opportunity to kill 

 them with a disk before sowing time. Earlier sow- 

 ing also results. This has proved to be of special 

 benefit in those localities where it is necessary for 

 the crop to have a good start before the winter's 

 freezing sets in. It has been proven many times that 

 dry plowing immediately following the harvest is the 

 means whereby a crop is made possible where other- 

 wise none could be grown. This dry condition nearly 

 always takes place on soil that cannot be plowed while 

 hard and dry with a mouldboard plow. 



The disk plow will handle very gravelly soil where a 

 mouldboard plow cannot work. The principal reason 

 for this is that the disk plow does not cut so wide a 

 furrow as the mouldboard. The gravel in these narrow 

 furrows is separated with the rolling motion of the disk 

 much more effectively than can be done with the crunch- 

 ing, pulverizing action of the mouldboard. Another 



