Cynodon dactylon: An efficient perennial grass to revegetate sodic lands

Sodic soils are wide-spread in semi-arid subtropical regions and characterized by high level of sodium and pH with poor physical, microbial and enzyme activities. In this study frequency (F), density (D), abundance (Ab) and important value index (IVI) of grasses naturally growing on abandoned sodic land were observed to assess sodicity tolerance ability of these grasses. The greatest IVI and visual observations showed that Cynodon dactylon (Bermuda grass) has maximum ability to grow on severely sodic lands and can be identified as an ecological tool in rehabilitation of degraded lands. Besides vegetation analysis, this further would be confirm by analysis of microbial and enzyme activities of rhizosphere soils. Therefore, we also observed the changes in microbial and enzyme activities of rhizosphere soils (RS) of C. dactylon and compared with non-rhizosphere (adjacent non-vegetated area) sodic soils (NRS) to assess its ecological suitability for reclamation of sodic soils. We collected 135 random soil samples from C. dactylon rhizosphere as well as adjacent non-rhizosphere bulk soil. Soil pH, exchangeable sodium percentage (ESP), sodium adsorption ratio (SAR), electrical conductivity (EC) and carbon nitrogen ratio (C:N) were significantly lower in rhizosphere soils in comparison to non-rhizosphere soils, while organic carbon (OC), total nitrogen (T-N), available phosphorus (P), microbial biomass carbon (MBC), soil respiration (SR), microbial quotient (Cmic:Corg), dehydrogenase, protease and alkaline phosphatase activities were significantly higher in rhizosphere soils. Decreases in soil sodicity (pH, ESP and SAR) and increases in soil nutrients, microbial biomass and enzyme activities suggest that C. dactylon can be used to restore and enhance the biological activities of abandoned sodic lands and to facilitate the further vegetation establishment.

► Cynodon dactylon grows well on sodic soils but in sparse patches.
► Microbial and enzymatic activities were assessed in rhizosphere and bulk soil.
► Activities were significantly greater in rhizosphere than non-rhizosphere soil.
► C. dactylon alleviates sodicity and increase microbial activities in sodic soil.
► C. dactylon – a potential biological tool for effective restoration of sodic soil.