Bentonite could be an eco-friendly windbreak and sand-fixing material

Desertification has become a global environmental problem that poses great challenges to sustainable development in desert areas. Bentonite is a natural mineral with many environmentally-friendly traits, such as hygroscopicity, adsorbability, distensibility, cohesiveness, and pollutant-free. In this study, different amounts of bentonite were tested as windbreak and sand fixing materials in indoor and outdoor environments. When added to sandy soil, bentonite filled the interspaces between sand particles, bonded sand particles and formed sand grains aggregate. And it has significant effects on sand-soil physical properties and compression strength. Soil–water retention and soil physical properties were significantly improved at 1% bentonite (p<0.05). Additionally, the erosion rate was reduced by more than 99% when the proportion of bentonite was 0.2% bentonite. Whereas, at 2% bentonite, the shear strength was 0.26 kg cm−2 reached a significantly higher level than the biological crust (0.15 kg cm−2) (p<0.05), and at 5% bentonite, the compression strength was 2.3 kg cm−2. Most importantly, the cost of raw materials ranged from about $1,000-5,000 per hectare since it is naturally occurring and can be used in low content ratios in the sand—a much cheaper alternative than other sand prevention measures.