Biopolymer-based wind erosion mitigation using guar gum and agar gum

Wind erosion threatens soil productivity and exposed-surface stability in arid environments. This study compared guar gum and agar gum for stabilizing a poorly graded sand, a silty sand, and a low-plasticity silt. Unconfined compressive strength (UCS), wind-tunnel erosion, water contact angle, crust integrity, and optical microscopy were evaluated under different biopolymer concentrations, expressed relative to water mass, and curing conditions. The strongest response was obtained with 2.0% guar gum after 7 d of oven curing, yielding UCS values of 1369 kPa in the silty sand and 1003 kPa in the poorly graded sand. During 15 min of airflow at 144 km.h -1 , guar gum reduced soil loss by more than 99.9% in both sands and by over 92% in the silt. Agar gum also provided near-complete protection in both sands but achieved about 90% reduction in the silt. The silty sand showed the most favorable balance between particle packing and polymer bridging, whereas the silt’s higher specific surface area was associated with lower strength and greater residual erosion. Repeated guar-gum coating improved short-term surface sealing, while microscopy confirmed particle coating, interparticle bridging, and coherent crust formation. Overall, guar gum provided the most consistent combination of strength enhancement and erosion resistance.