Soil treatment using microbial biopolymers for anti-desertification purposes

Abstract

Desertification and soil degradation are becoming more serious due to global warming and concurrent extreme climate events. Although anti-desertification efforts have been mounted worldwide, most undertakings have shown poor performance because of failure to consider soil and geotechnical aspects. Soil erosion is accelerated by reductions in soil cohesion and water retention due to the transfer of fine particles from the original ground. Thus, soil internal cohesion must be recovered to ensure effective and reliable anti-desertification attempts. In this study, soil treatment using biopolymers is suggested as an alternative method to prevent soil erosion and for revitalization, taking into consideration engineering and environmental aspects. Even as a relatively small part of the soil mass (i.e., 0.5-1.0%), biopolymers in soil have the positive potential to significantly reduce the erodibility of soil by enhancing inter-particle cohesion. Moreover, biopolymer treatment also improves both vegetation germination and soil water retention characteristics against evaporation, and therefore can provide suitable environments for plants and crops used as a desertification countermeasure in arid and semi-arid regions where annual precipitation is limited. We suggest combining biopolymers with pre-existing anti-desertification efforts (e.g., afforestation and windbreaks) on desert fronts (i.e., boundaries between arid and semi-arid regions) for best efficiency.