120 SOILS 



A very slight difference in the lines of the mould- 

 board may make wide results in plowing. Much 

 depends upon the nature of the soil. Sandy soils 

 may be plowed with a flat furrow-slice with much 

 less detriment than clayey soils, which need much 

 loosening and pulverising. If a tenacious soil is 

 plowed so that the furrow-slice is completely in- 

 verted it is much heavier and colder, for the season 

 at least, than if the furrow-slices were overlapped. 



Plowing to Prepare the Seed-bed. It is expen- 

 sive work fitting soil to receive the seed. Plowing 

 usually represents less than one-half the cost of 

 preparing land for the crop ; harrowing, dragging, 

 planking, etc. if well done, cost more. One of the 

 objects in plowing, then, should be to leave the 

 soil in such a condition that as little subsequent 

 tillage as possible will be needed to fit the land for 

 the crop. This means that the plowman should 

 not be satisfied with the handsome flat-furrow 

 plowing that took prizes at the agricultural fairs 

 50 years ago, but which requires much expensive 

 harrowing to make it mellow. He should turn a 

 furrow-slice that is just as loose and crumbly as 

 possible and still bury the trash, so that the labour 

 of harrowing may be reduced. The kind of plow 

 that should be used, and the condition in which the 

 land should be left, depends upon the kind of soil 

 and the crop to be grown upon it; but whenever 

 a plow is purchased its ability to pulverise the soil 

 should be the chief measure of its value. 



Plowing to Promote Fertility. It does this by 

 all the ways mentioned in the previous chapter. 

 It exposes the soil to weathering more completely 

 so that more of its insoluble plant food is made 

 available. It lets in the air which corrodes the 

 minerals, forms carbonic acid with the humus and 



