3) Dr. Tamir Caras

Soil erosion, the detachment and transport of topsoil by water and wind, is a major driver of land degradation in dryland agriculture. While natural factors such as rainfall, soil, and topography influence erosion, management practices, particularly tillage, strongly amplify its effects. This study quantified erosion and biomass under different tillage practices using UAV-based LiDAR, multispectral, and RGB data at the Gilat LTER research station in the northern Negev, Israel. Four treatments: disk cultivation, minimum tillage (cultivator tillage/kilter), and no-tillage with/without controlled grazing, were applied within a single wheat field to isolate management effects while holding site factors constant. Over two growing seasons, field measurements (sediment traps and biomass harvests) were combined with UAV-derived indicators, including microtopographic roughness and net volume change from LiDAR, as well as vegetation cover indices from spectral imagery. The Revised Universal Soil Loss Equation (RUSLE) was also applied at micro- (1 cm) and macro-scale (4 m) resolutions using UAV-derived inputs. Results showed clear differences among treatments: Disk and cultivator tillage plots exhibited higher erosion rates, reduced biomass, and altering vegetation composition, whereas no-tillage plots retained more soil and biomass. Interestingly, ungrazed no-tillage plots experienced greater erosion than grazed plots, suggesting that grazing influenced ground cover structure and surface compaction. Cumulative RS estimates for trap-plots corresponded closely with sediment-trap empirical measurements, supporting the reliability of UAV-based data collection. Overall, UAV remote sensing proved effective for field-scale erosion monitoring. Findings highlight that tillage choice critically shapes soil stability and productivity in dryland systems, providing practical insights for sustainable land management.