Measurement of roughness lengths of ploughed soil by using a pin roughness meter

Surface roughness of cultivated soil that can be characterized by aerodynamic roughness length (z0) has important implications to wind erosion. Field experiments were conducted in South Tunisia over two plots tilled with different ploughing techniques (mouldboard and tiller). The resulting surface is characterized by well marked ridges of different spacing and height. Measurements of soil surface geometric roughness were performed using a pin roughness meter. Here we report results of the computation of aerodynamic roughness lengths by applying established relationships between z0 and geometric characteristics of tilled ridges. These results suggest that parameterization could be used to estimate the aerodynamic roughness length induced by tilled surfaces when the geometric characteristics of ridges are known.