No. 6. DEPARTMENT OF AGRICULTURE. 465 



The Effect of Tillage. 



In the next place, the moisture in the surface soil may be very 

 largely retained if shortly after the plowing is done the cultivator 

 and harrow are used to make still more fine the particles of earth 

 thrown up by the plow, thus retaining in part that which would es- 

 cape if the tillage w^ere not practiced. Tillage, to conserve moisture, 

 while confined to the cultivated crops, as corn and potatoes, does 

 exert an influence also upon these crops, which by virtue of their 

 character cannot be cultivated, as hay, wheat, etc., as well as upon 

 the others, because previous tillage, viz: harrowing, plowing, etc., 

 are operations which result in breaking up the particles of soil and 

 thus making the surface soil itself a place where w^^ter will pene- 

 trate more readily and freely, as well as enabling the roots to 

 ramify freely in every direction, and giving them a larger surface 

 area from which to draw their moisture in times of drouth or in 

 frequent rains. It is apparent, therefore, that tillage exerts an 

 influence in conserving the moisture, not only for the immediate 

 crop, but for future crops as well, because improving the soil in 

 such a way as to make it more absorptive and retentive of the water 

 which falls a considerable time previous to the planting of the crop. 



The Object of Drainage. 



In the next place, drainage is an important operation in improving 

 the absorptive and retentive power of soils for water. A common 

 idea is that drainage by lowering the water-table is only intended 

 to remove the moisture that is present in too great amounts and 

 that it does not exert any influence in providing moisture for crops 

 during a period of insufficient rainfall. This idea is in part errone- 

 ous, for the very fact that the w^ater-table is lowered enables a more 

 rapid percolation of the w^ater of the rains in every direction in the 

 soil, than if the drains were not there, and as the water percolates 

 and is absorbed more fully, the crops that follow have a larger area of 

 moist surface to draw their water from than if the surface area of 

 the soil through which the roots can penetrate was limited. Be- 

 sides, the lowering of the water-table has a very importanrt; in- 

 fluence in improving the absorptive property of soils by virtue of 

 the fact that it enables the penetration of the air to greater depths, 

 which changes its physical and mechanical character, making heavy 

 soils, particularly, more open and porous. 



The Advantages of a Mulch. 



Another method which is only practicable for small areas, is the 

 use of a mulch, which may consist of any loose material spread over 

 30—6—1902 



