Effect of Tillage on Surface Roughness

ABSTRACT THE effect of tillage on surface roughness was investi-gated. Several tillage operations were studied: chisel, chisel plus disking, and chisel plus disking plus harrowing. Roughness was quantified in terms of a new, dimensionless parameter being the product of a microrelief index and peak frequency factor. Transect-based determinations of surface elevations yielded roughness values which followed the sequence: chisel > chisel plus disking > chisel plus disking plus harrowing. Different transect spacings were required for each tillage system to obtain independent estimates of the roughness parameter. Uniformity in surface roughness was greatest for the chisel plus disking plus harrowing plot and least for the chisel plus disking plot.