Abstract:Using a laser profiler, the surface height variation trace of three types of tillage soil profiles-ploughed, harrowed and rolled surface were obtained. In order to acquire the different direction profiles of every tillage type, the profiles at 0, 45 and 90 degrees with respect to the tillage direction were measured. With these data, the ranges of root mean square height and fractal dimension were estimated, compared with root mean square height, fractal dimension have been well related with tillage soil surface. Two soil surfaces may present different characteristics with same fractal dimension and different root mean square height. So the complex behavior of different tillage soil profiles could be well described by using surface roughness exponent with combination the fractal dimension and root mean square height. The higher surface roughness parameter is, the more roughness of soil surface would be.