PLOWING IN DRY AREAS 131 



proper growing of the next crop. But deep plowing is to 

 be preferred in the autumn when it can be done, as, 

 should rain come, many western soils can take up 40 

 per cent, of moisture. One-third of that amount rightly 

 used will grow a good crop. (3) Where plowing is done 

 in the late spring and a crop is to be grown on it that 

 season, as the crop will start readily in the top soil thus 

 loosened and the roots find firm soil below. 



The depth of the plowing in dry areas should not be 

 uniform, that is it should be deeper for some purposes 

 than others. If land is plowed uniformly at the same 

 depth from season to season the soil at the bottom of the 

 furrow becomes hardened by the smoothing and com- 

 pressing action of the sole of the plow and the tramping 

 of the horses. This condition is unfavorable to capillary 

 action. When land is broken deeply, as it should gen- 

 erally be broken, it will be better in some instances to 

 plow say two inches shallower the next time, so that 

 the buried sod may have longer time to decay before it 

 is again exposed to drying atmospheric influences. The 

 plan of plowing sod land shallow and then backsetting 

 it later in the season by plowing it more deeply, has 

 found favor in many of the provinces of Canada and in 

 some portions of the north western states. 



The kind of plow to use. Plows as adapted to work 

 in dry areas may be divided into three classes. These 

 are: (1) the mold-board plow; (2) the disc plow, and 

 (3) the deep tilling machine. Of the first two there are 

 several modifications. 



The mold-board plow cuts the furrow slice and turns 

 it over. Owing to the shape of the mold-board, it packs 

 the furrow slice more or less, thus causing it to lie more 

 or less smoothly against the furrow previously turned. 

 A plow' with a long mold-board is best for some kinds 

 of breaking. One with a short mold-board and pos- 

 sessed of abrupt curvative aids to some extent in 



