Saturated hydraulic conductivity was found to decrease linearly
with soil depth (r=−0.82) with the largest change from the Ap to the
AE horizon (1st to 2nd 10 cm increment). Roots and organic matter
from the permanent vegetation, well-preserved pore networks, and
enhanced macropore flowmay have contributed to these observations
(Obi, 1999; Mishra et al., 2003). Approximately 60–80% of the crop,
grass, and tree roots occupy the surface 0 to 10 cm soil and roots and
root channels can develop into connected pores (Chaturvedi and Das,
2003; Udawatta and Henderson, 2003).