SELECTION OF A PARAMETER DESCRIBING SOIL SURFACE-ROUGHNESS

An evaluation was conducted on eight roughness parameters, including maximum peak height, a microrelief index (the area per unit transect length between the measured surface profile and the least-squares regression line through all measured positions of the transect), peak frequency, and MIF (the product of the microrelief index and peak frequency). The objective of the study was to select the parameter being the best descriptor of soil surface roughness. An automated, noncontact profiler was used to obtain surface profiles along transects, 5-cm apart, of 1-m by 1-m plots after a cultivation and a simulated rainfall application at each of three different stages of soybean development. Study results are discussed.