THE MEASUREMENT OF STRUCTURAL STABILITY AND PERMEABILITY AND THE INFLUENCE OF SOIL TREATMENTS UPON THESE PROPERTIES

Abstract

Structural stability and permeability of soil to water control aeration, root penetration, absorption of water, and internal drainage. A method of aggregate analysis is descr. by which the stability index and probable permeability may be calculated. Using the method on field expts. it was shown that: (a).A rotation of corn, oats, wheat and clover over a period of 58 yrs. caused a breakdown of aggregates as compared with sod land adjacent; (b) a vegetable cropping system, including no sod crop and with cover crops only for soil improvement, produced after 21 yrs. a poorer structural condition than the rotation descr. in (a); (c) farm manure produced physical improvement; (d) liming did not alter the structural condition; (e) other things being equal, structural stability was closely correlated with organic content; and (f) the volume wt. showed a close inverse relationship with organic content and structural stability.