Why is moisture retained longer in the soil if it is harrowed?

Explanation

When the soil is not harrowed, there are large capillaries in it. Water in the soil risesup the capillary holes to the surface from where it evaporates continously. Thus the soil continously loses water. When harrowed, all these capillaries are destroyed, and so capillary suction stops altogether. Thus, water is retained longer in the soil.