Controlling rainfall-induced soil loss from small experimental plots through inoculation of bacteria and cyanobacteria

Abstract

Soil erosion is a major limitation for achieving sustainable development. Controlling soil detachment in initial stage of soil erosion induced by rainfall is necessary. Several organic and inorganic amendments have been used to reduce rainfall-induced erosion. Meanwhile, the impact of soil microorganisms has been approved on improving soil aggregation by previous studies. However, studying the feasibility of inoculation of soil microorganisms to reduce soil loss by rainfall-induced erosion has not been considered yet. Hence, the present study was planned to investigate the controllability of soil loss induced by rainfall-induced through the inoculation of bacteria and cyanobacteria into a study soil. Soil samples were collected from an erosion-prone area from which suitable existing bacteria and cyanobacteria for soil and water conservation were selected, purified and proliferated. The bacteria and cyanobacteria were then inoculated into 24 small 0.25 m2 plots in individual and/or combined treatments at three time spans of 15, 30 and 60 days. The results illustrated a significant decrease in soil loss from treated plots (p < 0.01). Moreover, the highest effectiveness was observed in the cyanobacteria and the combined treatments at the end of the 60 days-period (p < 0.01) with respective reduction rate of 99 and 98% in soil loss. Based on the study results, the use of microorganisms, particularly direct inoculation of bacteria and cyanobacteria can be supposed as a new step, biologic, sustainable, environmentally-friend and economically-effective technique for soil conservation.