Dr. G K Dinesh, Researcher on Agriculture and Ecosystem services from India

Ecology of Birds and Insects in Organic and Conventional (In-Organic) Rice Ecosystem

International Journal of Current Microbiology and Applied Sciences 7(04):1769-1779 

Project: Ecology of birds and insects in organic and inorganic rice ecosystem

This Investigation was undertaken in the wetlands farm of Tamil Nadu Agricultural University, Coimbatore during Thaladi season to study the ecology of birds and insects in inorganic and organic rice ecosystem, with special reference to the species abundance, diversity, richness, evenness and similarity indices. This study revealed that organic cultivation supports bird diversity and beneficial insects. However, the bird menace during maturity stage is an issue to be managed in an ecofriendly way. 

Effect of no-tillage practices on Carbon Management Indices in a Sandy Loam Soil of India

Journal of Agricultural Physics

After six years of continuous Conservation Agriculture practices, we investigated the impact of crop residue retention and green seeker N fertiliser supply on soil carbon indices. The lability of carbon appears to be more in zero tillage without residues (ZTWoR) plots than zero tillage with residues (ZTWR). More carbon pools were observed in 33%N+GS and 50%N+GS treatments, and the trend was 33%N+GS > 50%N+GS > 70%N+GS or RDN. CMI was higher in the 15 -30 cm layer than the 0 - 15 cm soil layer. CMI values were high in the residue-retained plots compared to non-residue retained plots. In ZTWR plots, CMI values ranged from 150.22 ± 7.37 and in ZTWoR plots, values ranged from 145.33 ± 1.09. From the study, Zero tillage with residue retention improves CMI values in the soil; hence it is recommended to improve the soil fertility and quality. 

Evaluation and speciation of heavy metals in the soil of the Sub Urban Region of Southern India

Soil and Sediment Contamination (formerly Journal of Soil Contamination) 31(6):1-20

DOI: 10.1080/15320383.2022.2030298

Project: DST- SERB funded ECR Award for the project entitled as "An Integrated Remediation Approach for Chromium Contaminated Soil and Waters in Vellore, Tamil Nadu"

Labs: National Agro Foundation

This study examines the pollution of soil by chromium using statistical analysis and Empirical Bayesian Kriging (EBK) modeling around the leather tanning industries of Southern India. Sixty-four soil samples were collected from agricultural lands and analyzed for their major ions and trace elements using Atomic Absorption Spectrophotometer. It is observed that the concentration of trace elements, decreases in the following order: Cr > Fe > Ni > Pb > Mn > Cu > Zn. Also, the chromium present in the soil samples ranged between 0.1 and 2459 mg/kg. The higher concentration of Cr, Pb, Ni, and Zn observed in this study exceeds the permissible limit around tannery regions, indicating tannery effluents’ impact. The positive correlation of Cr with Ca, Mg, Pb, and Mn specifies the discharge of tannery wastewater into the open land, thus contaminating the soil in the study area. The root mean square error (RMSE) values derived from the EBK model for Cr, Pb, Fe, and Ni are close to 1, indicating the model’s validity. Moreover, the soil pollution index and Geo-accumulation index results around the tannery region show a profound impact of tannery effluent. The obtained results clearly emphasize the presence of toxic heavy metals in the study area that may cause extensive degradation of productive agricultural land. Hence, it is essential to make an appropriate strategy and implement a suitable remediation technique to solve the heavy metals pollution problem. 

Chemical transformation and bioavailability of chromium in the contaminated soil amended with bioamendments

• Bioremediation Journal

• DOI: 10.1080/10889868.2022.2049677

• Project: DST- SERB funded ECR Award for the project entitled as "An Integrated Remediation Approach for Chromium Contaminated Soil and Waters in Vellore, Tamil Nadu"

The biotoxicity of chromium (Cr) present in the soil is determined by the transformation and bioavailability of chemical species. A better understanding of these factors aids in developing appropriate remediation strategies for Cr contaminated soils. The present work studied the transformation of Cr in soil and the effect of bioamendments by conducting a laboratory closed incubation experiment of 60 days (duration). The physical properties of the contaminated soil were enhanced by the addition of bioamendments such as farmyard manure, composted poultry manure, pressmud compost, and biochar with two moisture conditions. The biochar reduced the bioavailable fractions of Cr due to the high surface area. Therefore, it facilitates a higher adsorption rate, whereas poultry manure and pressmud compost increased the bioavailability of Cr. The pH ranged from 7.04 to 8.25 throughout the experiment in both the condition. Comparing the other fractions, higher concentration was recorded in the residual fractions of 89.85 to 124.77 mg Kg−1 in the field capacity condition and 93.85 to 114.29 mg Kg−1 in alternate wetting and drying conditions. FTIR analyses of bio-amendments demonstrated similar variations in physicochemical characteristics wherein higher concentration was observed in biochar (3700–3200 cm−1). A significant reduction of bioavailable fractions of chromium was observed in biochar (80%) amended soil, followed by farmyard manure (70%). The lowest reduction was observed in the pressmud amended soils (55%). Biochar amended soil significantly reduced the fractions of Cr and increased the organic carbon; thus, it demonstrating the impacts of bioamendments on the mobilization or immobilization of Cr in the contaminated soil, and this can be effectively used in the bioremediation of Cr contaminated soil. 

Chromium Speciation and Agricultural Soil Contamination in the Surrounding Tannery Regions of Walajaphet, Vellore District, Southern India

• Madras Agricultural Journal 109(March)

• DOI:10.29321/MAJ.10.000586

• Project:DST- SERB funded ECR Award for the project entitled as "An Integrated Remediation Approach for Chromium Contaminated Soil and Waters in Vellore, Tamil Nadu"

The emerging environmental problem in the tanning industry is the disposal of chromium-contaminated sludge in the soil. In the Walajapet Taluk of the Vellore District, the distribution and mobility of chromium in the soils and sludge surrounding the tannery waste disposal region were explored. This paper presents soil contamination of agricultural lands located in the SIPCOT Industrial complex near Walajapet in Vellore District, India. 64 soil samples were collected from 15 different villages, and the soil samples were analyzed for pH, EC, total chromium, hexavalent, and trivalent chromium. Studies were carried out to find the chromium contamination of the agricultural lands due to industrial effluents. It is found that 75 % of the agricultural soil samples were highly contaminated, posing a risk to agricultural lands, based on the comparison of chromium in the soil with WHO standards. The majority of the soil samples (>80%) from the locations exhibited high Cr (>200 mg kg-1) concentrations that exceeded the maximum permissible limit. Furthermore, soil samples taken near tanneries revealed that tannery effluent has a significant impact. The facts strongly demonstrate the existence of hazardous chromium, resulting in severe deterioration of agricultural land. As a result, developing an effective plan and implementing a suitable remediation technique to address the heavy metals contamination problem is critical.

Groundwater quality assessment for agricultural purposes at Vellore District of Southern India: A geospatial based study

• Urban Climate 47(January 2023):101368

• DOI:10.1016/j.uclim.2022.101368

Identifying the geographical distribution of contaminants and their severity in polluting water are critical components of water resources management. Untreated industrial effluents cause severe groundwater pollution and health hazards worldwide. Therefore, the present study was carried out in the year (2019-2020) to assess the groundwater quality in the industrial areas of Vellore district, Tamil Nadu, India. Sixty-four groundwater samples were collected from different villages and analyzed. Spatial distribution maps were prepared to evaluate groundwater quality. The results revealed that among the various heavy metals, total Cr (140 mg/L) contamination was higher in the groundwater samples and hazardous for human consumption and irrigation purposes as per the permissible limit of chromium prescribed by WHO (0.05 mg/L). It is observed that the concentration of heavy metals decreases in the following order: Cr > Ni > Pb > Cd. The irrigation quality index was found to be high in Walajah Taluk in the order of Residual Sodium Carbonate<Magnesium Hazard<Permeability Index<Sodium Absorption Ratio. Regular monitoring of pollutants and appropriate remediation must be followed to avoid deterioration of groundwater quality. This study's findings can help to determine the best course of action to safely use groundwater for irrigation purposes in the Vellore District of India. 

Phytoextraction Potential of Chrysanthemum and Cumbu Napier Hybrid Grass to Remediate Chromium-Contaminated Soils Using Bioamendments

• International Journal of Environmental Research 17(1):8

• DOI:10.1007/s41742-022-00496-5

Chromium is one of the most toxic heavy metals impacting soil quality and human health. However, remediating Cr from contaminated environments and soil by the chemical method is uneconomic and unsustainable. Phytoremediation is a potential, eco-friendly and cost-effective technique to decontaminate Cr from the soil. In this study, chrysanthemum and Cumbu Napier hybrid grass were grown with various amendments in the pots to evaluate their phytoextraction potential to remediate Cr-polluted soil. In the treatment (T3-composted poultry manure), Cr concentration above 300 ppm was slightly toxic to the chrysanthemum, resulting in the reduction of flowers. Cumbu Napier grass had good growth in all the treatments. The productivity of Cumbu Napier grass was excellent, and 80% of Cr accumulation was in the T4 treatment (Cr + 5 t ha−1 of press mud compost) compared to other treatments. Cr removal was maximum with Cumbu Napier, followed by chrysanthemum because of its higher biomass. According to Cr partitioning, a high concentration was found in the roots, followed by shoots and flowers. Thus, both crops with added bioamendments are excellent options for phytoremediation. Results suggest that plants grown with bioamendments pose a promising future for developing a sustainable, cost-effective methodology for chromium removal from the soil.