Increasing soil potential for carbon sequestration using microbes from biological soil crusts

Dryland soils have the potential to be large atmospheric carbon (C) sinks, thus aiding in managing global warming. In these areas, soil micro-organisms found in biological soil crusts (biocrusts) can play a major role in C cycling, especially by influencing the fluxes between the atmosphere and soil; however, their potential has been reduced due to degradation. Thus, we assessed how inoculating soil micro-organisms and adding microbial stimulant nutrients onto a degraded soil affected C sequestration. Therefore, a full factorial combination of bacteria, cyanobacteria and nutrients was added to the field-collected soil. After 60 days, we measured the effect of this inoculation with and without support by a nutrient (B4) addition on the soil organic C; then, we calculated the C sequestration and the potential CO2 removal from the atmosphere. We found that inoculating bacteria, cyanobacteria, or a combination of them increased the sequestrated C in the soil from 0.232 to 0.294 g m(-2) day(-1) at the plot scale; when calculations were used to scale up, this increase was from 0.84 to 1.07 ton ha(-1) year(-1). This could remove 3.11-3.93 ton ha(-1) year(-1) of CO2 from the atmosphere. However, nutrient addition had no significant effect on the C pools.