PLOWING IN DRY AREAS 129 



to which it. had been plowed. The excess of the rain 

 above what the 3 inches of soil will absorb must run 

 away over the surface, and in doing so it will carry away 

 the finer and more valuable portions of the soil in propor- 

 tion as such excess of precipitation is present. Buffum 

 has affirmed that soils which will hold 20 per cent, of 

 moisture will not store more than 7-10 inches of rain 

 when plowed 3 inches deep, nor more than 1.4 inches 

 when plowed 6 inches deep, but when plowed 9 inches 

 they will store more than 2 inches of rain. Water thus 

 caught will sink down slowly into the lower soil 

 and will thus tend to equalize its movements and distri- 

 bution. (2) It improves the tilth and the producing 

 powers of soils. These results follow from the pulver- 

 izing influences brought about by the deep stirring of 

 the land and from the increase in aeration, warmth, and 

 in the activity of bacterial agents in the soil. (3) It en- 

 larges the feeding ground for the roots of plants, because 

 of the greater ease with which their roots may find food 

 in a soil thus broken and stirred. (4) Lifting with the 

 winds may to some extent be reduced because of the 

 more pronounced character of the depressions between 

 the furrows. But too much must not be made of this ad- 

 vantage, as it is frequently necessary to obliterate such 

 furrows soon after plowing by the use of implements of 

 tillage. 



The depth to plow will vary with the soil. It should 

 seldom be less than 6 inches or more than 10 inches. 

 When plowing deeply, the timeliness for this and the cost 

 of the same should not be lost sight of. It may cost 

 less in one instance to plow soil 7 to 8 inches than to 

 plow it 4 inches in another instance, because of a differ- 

 ence in the moisture content in the soil. Deep plowing 

 is never more opportunely done than in connection with 

 the plowing of fallow land, providing the latter is plowed 

 at that season when it has the largest amount of mois- 



