Soil Roughness Estimation Using Fractal Analysis on Digital Images of Soil Surface

Irregularities of soil are defined by the term soil surface roughness and various factors affect it such as tillage operations, land management, soil texture, etc. Soil roughness impacts water infiltration and surface storage level, as well as wind and water erosion. We used two classical methods for soil roughness estimation based on chain and pinboard and tested their effectiveness in lab and in situ measurements. However, we concluded that even though these two methods are perfectly correlated when they are aligned on the same line over the sample surface, in-field results showed the opposite. Thus, we propose a new soil surface roughness measurement method based on fractal analysis of digital images of the soil surface, acquired using a camera obscura-based technique. We show that the 2D fractal analysis gives more pertinent results compared to the other methods designed for 1D measurements.