Sodicity is one of the major salt stresses that impair crop production. Exopolysaccharide-producing sodic tolerant bacteria (EPS-STB) play a significant role in reducing the sodic stress in plants by hampering the uptake of sodium. In this context, this study aims to isolate the EPS-STB for alleviating sodic stress in rice under a sodic environment. Thus, artificial sodicity was created in culture media, and 253 bacteria were isolated from the rice rhizosphere of sodic soils in Trichy and Chinna Salem of Tamil Nadu in India. Fifty bacterial isolates were initially screened based on EPS production, sodic tolerant ability, and plant growth-promoting activities. Further, these bacterial isolates were identified using 16S rDNA sequencing. The results suggested that the isolated bacteria possessed biofilm-forming abilities along with plant growth-promoting activities and osmolyte accumulation under sodic stress conditions. Bacillus rugosus L1C7T, Bacillus paralicheniformis L1C5L, Pseudomonas sp. L5C14T and Franconibacter helveticus L2C1L2 were chosen as better EPS-STB plant growth-promoting bacteria, and their impact on rice under sodic conditions was evaluated. Among the sodic tolerant bacteria, Franconibacter helveticus L2C1L2-inoculated rice plants increased dry matter production compared to the control. Thus, this study showed that the utilization of EPS-STB will become a promising tool to alleviate sodic stress in rice.

Accelerating land-use change (LUC) in the Nilgiri Hill Region (NHR) has caused its land to mortify. Although this deterioration has been documented, the destruction of buried gem soil has not been reported. Therefore, this study was conducted to assess the impact of LUC on soil-carbon dynamics in the six major ecosystems in the NHR: croplands (CLs), deciduous forests (DFs), evergreen forests (EFs), forest plantations (FPs), scrublands (SLs), and tea plantations (TPs). Sampling was conducted at selected sites of each ecosystem at three depth classes (0–15, 15–30, and 30–45 cm) to quantify the carbon pools (water-soluble carbon, water-soluble carbohydrates, microbial biomass carbon, microbial biomass nitrogen, dehydrogenase, and different fractions of particulate organic carbon). We found that the LUC significantly decreased the concentration of carbon in the altered ecosystems (49.44–78.38%), with the highest being recorded at EF (10.25%) and DF (7.15%). In addition, the effects of the LUC on the aggregate size of the organic carbon were dissimilar across all the aggregate sizes. The relatively high inputs of the aboveground plant residues and the richer fine-root biomass were accountable for the higher concentration of carbon pools in the untouched EFs and DFs compared to the SLs, FPs, TPs, and CLs. The results of the land-degradation Index (LDI) depicted the higher vulnerability of TP (−72.67) and CL (−79.00). Thus, our findings highlight the global importance of LUC to soil quality. Henceforth, the conservation of carbon pools in fragile ecosystems, such as the NHR, is crucial to keep soils alive and achieve land-degradation neutrality.

Rice husk ash (RHA) contains appreciable amounts of exchangeable cations and plant nutrients which can be used as liming material for acid soil reclamation. Hence, the present study was carried out to assess the potential of rice husk ash for soil acidity reclamation and its effect on related soil properties. RHA was collected from a modern rice mill and its physical and chemical properties were assessed. The results confirmed the alkaline nature of RHA with a pH of 8.30 at 1:10 RHA-to-water suspension. An incubation experiment was conducted with five levels of RHA viz., 10, 20, 30, 40 and 50 t ha-1; compared with the treatments without liming material and the lime application as per lime requirement. Soil sampling was performed at 15, 30, 45 and 60 days after incubation (DAI) and analysed. The results indicated that the application of RHA 50 t ha-1, 40 t ha-1,30 t ha-1 and lime (100% lime) were comparable in enhancing the soil pH, effective cation exchange capacity and percent base saturation and reduced the total acidity and exchangeable Al. With all levels of RHA and lime application, favourable effects on soil properties related to acidic soil reclamation were observed over time. Exchangeable Ca and Mg were the highest in the 100% lime requirement, followed by RHA at 50 t ha-1. Exchangeable K and Na were the highest in rice husk ash at 50 t ha-1. The results emanated from this study ensured the potential of rice husk ash as a source of lime for acidic soils reclamation.