Experimental Study on Wind Erosion Resistance and Plant Growth Performance of Coastal Sand Stabilized by Soybean Hull-Enzyme-Induced Carbonate Precipitation and Seawater

To combat coastal wind erosion and develop sustainable stabilization technologies, a resource-efficient technique was developed based on the Enzyme-Induced Carbonate Precipitation (EICP) principle in the coastal regions of China. Utilizing seawater as a multi-ion source and discarded soybean hulls (Glycine max (L.) Merr.) as a crude urease source, this method is synergized with vegetation to form an environmentally friendly anti-erosion strategy. This study first explored the feasibility of soybean hull-derived urease, then analyzed the impacts of urease activity, reaction liquid volume, and seawater concentration on the germination and growth of Kalimeris indica. The results show that the biochemical mineralization process effectively sequesters soluble Ca2+ and Mg2+ from seawater into stable mineral phases, thereby mitigating salt-induced osmotic stress. Optimal plant growth was achieved at a seawater concentration of 0.2 mol·L−1 and a liquid volume of 200 mL. Furthermore, the biocementation provided robust protection for initial plant growth, achieving an approximately 92.3% reduction in soil loss. Despite the presence of nitrogenous byproducts, the synergistic effect of EICP crusts and developing root systems ensures long-term wind erosion resistance and ecological integrity. This study highlights a functional transition from artificial mineralization to biological anchoring for sustainable coastal restoration.