High-resolution morphologic characterization of conservation agriculture

In the last decade, conservation agriculture (CA) has received particular attention from both governmental and non-governmental organizations. CA aims to achieve sustainable agricultural production. The principles of CA include minimal soil disturbance, permanent soil cover derived from crop residues or cover crops, and crop rotations that benefit soil and water conservation. Agricultural practices influence the micro-topography and modify the surface roughness, altering several important processes such as infiltration, water storage depression, and soil water erosion. In this work, we explore the effectiveness of high-resolution topography in characterizing no-tillage (NT) versus conventional tillage (T) surface morphology in order to better understand the hydro geomorphic processes associated with these crop systems. High-resolution (2 cm) Digital Elevation Models (DEMs), derived using the Structure from Motion (SfM) photogrammetric technique, were processed for six plots (3 cultivated with NT, 3 with T) in a clay loam soil. The study area is located in northeast Italy. Several morphometric terrain parameters (e.g., connectivity, curvature and relative elevation attribute), were computed for each plot. The analysis provided challenging insights: compared to T, surfaces in the NT plots were rougher, had more pronounced slopes and curvatures, sediments with a widespread connection to the plot boundaries, had more irregular flow paths, and had a higher water storage potential due to surface concavities. This can be translated into a surface morphology that can significantly affect surface runoff, sediment transport, and the off site movement of agricultural chemicals.