40 



Campbell's 1902 Soil Cultuke Manual. 



sents a stratum of thoroughly pulverized and firm soil, meaning the por- 

 tion that is cut by the plow; C represents about eight inches of the sub- 

 soil into which water has percolated; and D represents the portion of sub- 

 soil still below that is yet dry. In section 2, we find the mulch has been 

 compacted by a heavy fall of rain. This mulch in its loose condition 

 readily takes in the water, and as soon as the water reaches the moist soil 

 found in strata B and C, it immediately percolates down l)elow, and is 



12 3 

 Cut No. S. 



shown by the darker portion of soil in the upper part of stratum D. Here 

 the water has come in contact with dry soil, which resists percolation. 

 Slowly and steadily by gravity the water finds its way down the columns 

 of soil, which, by the w^ay, throughout the entire semi-arid belt are almost 

 invaribly found in a perpendicular position. In sections 3, w^e have again 

 reproduced our soil mulch by cultivation to stop the evaporation or loss of 

 our water from the surface, and we find the moisture below^ has percolated 

 on down until the water i>^ all distributed, each little particle taking on its 

 film of water to a given thickness w^hich it seems to steadily hold onto 



