Soil Structure and Hydraulic Conductivity of Adjacent Virgin and Cultivated Pedons at two Sites: A Typic Argiudoll (silt loam) and a Typic Eutrochrept (clay)

Abstract

Soil morphology and hydraulic conductivity (K) of principal soil horizons of paired virgin and cultivated soil pedons were studied at two sites: a Tama silt loam (Typic Argiudoll) and an Oshkosh clay (Typic Eutrochrept). About a century of cultivation had led to reduction of K (measured by the Bouwer double-tube method) in the upper part of the solum below the Ap. Corresponding changes in soil morphology are noted. The reductions in K are paralleled by increases in bulk density and decreases in porosity and organic matter content in the soil horizons. At a depth of 80 to 90 cm in the clay soil, K increased apparently as a result of formation of interpedal voids as the alfalfa crop (Medicago sativa L.) extracted moisture.