Impact Assessment and Recommendation of Alternative Conjunctive Water Use Strategies for Salt Affected Agricultural Lands through a Field Scale Decision Support System – A Case Study

Conjunctive use of saline/non-saline irrigation waters is generally aimed at minimizing yield losses and enhancing flexibility of cropping, without much alteration in farming operations. Recommendation of location-specific suitable conjunctive water use plans requires assessment of their long-term impacts on soil salinization/sodification and crop yield reductions. This is conventionally achieved through long-term field experiments. However such impact evaluations are site specific, expensive and time consuming. Appropriate decision support systems (DSS) can be time-efficient and cost-effective means for such long-term impact evaluations. This study demonstrates the application of one such (indigenously developed) DSS for recommending best conjunctive water use plans for a, rice-wheat growing, salt affected farmer’s field in Gurgaon district of Haryana (India). Before application, the DSS was extensively validated on several farmers and controlled experimental fields in Gurgaon and Karnal districts of Haryana (India). Validation of DSS showed its potential to give realistic estimates of root zone soil salinity (with R = 0.76–0.94; AMRE = 0.03–0.06; RMSPD = 0.51–0.90); sodicity (with R = 0.99; AMRE = 0.02; RMSPD = 0.84) and relative crop yield reductions (AMRE = 0.24), under existing (local) resource management practices. Long term (10 years) root zone salt build ups and associated rice/wheat crop yield reductions, in a salt affected farmer’s field, under varied conjunctive water use scenarios were evaluated with the validated DSS. It was observed that long-term applications of canal (CW) and tube well (TW) waters in a cycle and in 1:1 mixed mode, during Kharif season, predicted higher average root zone salt reductions (2–9%) and lower rice crop yield reductions (4–5%) than the existing practice of 3-CW, 3-TW, 3-CW. Besides this, long-term application of 75% CW mixed with 25% TW, during Rabi season, predicted about 17% lower average root-zone salt reductions than the cyclic applications of (1-CW, 1-TW, 2-CW) and (2-CW, 1-TW, 1-CW, i.e., existing irrigation strategy). However, average wheat crop yield reductions (16–17%) simulated under all these strategies were almost at par. In general, cyclic-conjunctive water use strategies emerged as better options than the blending modes. These results were in complete confirmation with actual long-term conjunctive water use experiments on similar soils. It was thus observed that such pre-validated tools could be efficient means for designing, local resource and target crop yield-specific, appropriate conjunctive water use plans for irrigated agricultural lands.     

Inhibition of lipid peroxidation by extracts/subfractions of Chickrassy (Chukrasia tabularis A. Juss.)

Polyphenols and polyphenol-rich fractions of plants have been reported to have protective effects against lipid peroxidation, most probably by serving as scavengers of free radicals and/or by chelating metal ions. In the present study, the effect of different extracts/subfractions of Chickrassy (Chukrasia tabularis) on peroxyl radical mediated damage to the polyunsaturated fatty acids was investigated. Liver homogenate was used as experimental material. The production of malondialdehyde served as a marker of lipid peroxidation and oxidative stress. It was observed that polyphenol-rich fractions, particularly the ethyl acetate fractions of bark and leaves, showed the highest protective activity of 83.02% and 88.62% inhibition, respectively. This study will help in knowing the scientific validation of this plant, for its use in ayurvedic formulations. The current in vitro experiments performed herewith comply with the current laws of India.     

Coping with the ‘Indian summer’: unique nesting cycle and nest architecture of the paper wasp,Polistes wattii

The Science of Nature - Leaf-cutting ants are highly successful herbivores in the Neotropics. They forage large amounts of fresh plant material to nourish a symbiotic fungus that sustains the...     

Assessment of phenol-degrading ability of Acinetobacter sp. B9 for its application in bioremediation of phenol-contaminated industrial effluents

Successful bioremediation of a phenol-contaminated environment requires application of those microbial strains that have acquired phenol tolerance and phenol-degrading abilities. A newly isolated strain B9 of Acinetobacter sp. was adapted to a high phenol concentration by growing sequentially from low- to high-strength phenol. The acclimatised strain was able to grow and completely degrade up to 14?mM of phenol in 136?h. The degradation rates were found to increase with an increase in the phenol concentration from 2.0 to 7.5?mM. The strain preferred neutral to alkaline pH range for growth and phenol degradation, with the optimum being pH 8.0. The optimum temperature for phenol degradation was found to be in the range of 30–35°C. Transmission electron micrographs showed a disorganised and convoluted cell membrane in the case of phenol-stressed cells, showing a major effect of phenol on the membrane. Enzymatic and gas chromatography-mass spectrometry studies show the presence of an ortho-cleavage pathway for phenol degradation. Efficient phenol degradation was observed even in the presence of pyridine and heavy metals as co-toxicants showing the potential of strain in bioremediation of industrial wastes. Application of strain B9 to real tannery wastewater showed 100% removal of initial 0.5?mM phenol within 48?h of treatment.     

Catalytic advancements in carbonaceous materials for bio-energy generation in microbial fuel cells: a review

Environmental Science and Pollution Research - Microbial fuel cells (MFCs) are a sustainable alternative for wastewater treatment and clean energy generation. The efficiency of the technology is...     

Evaluation of decoloration potential of <Emphasis Type="Italic">Xanthium Strumarium</Emphasis> seed hull for adsorption of Direct red 81 in aqueous solution

An unmodified natural adsorbent, Xanthium Strumarium, was explored for its decoloration potential for treatment of textile effluents. Batch mode experimentation was carried out to optimize several process parameters with the well characterized adsorbent. For proper assessment of optimized pathway of adsorption, adsorption isotherms were implemented to the experimental data using nonlinear method. Apart from coefficients of determination, three error analysis methods standard error (S.E.), Chi-square (χ²) statistic and residual mean square error were additionally used to determine the best fitted isothermal model for the system. Freundlich model was creditably fitted to the adsorption data with minimum errors and high R ² values. The adsorption capacity obtained was 14.7, 15.2 and 18.7 mg g^?1 at 30, 40 and 50 °C, respectively. Overall adsorption process was endothermic with positive enthalpy and entropy values. Kinetic study revealed adsorption to be a two stage process initially controlled by film diffusion followed by pseudosecond order as the rate administering step during adsorption. About 95 % decoloration was achieved in 60 min. High decoloration tendency of the opted adsorbent proved that it is an effective and cheap adsorbent for treatment of coloured effluents providing a good alternative to activated carbon.     

Effects of tin on sulfhydryl containing enzymes in liver of rats

A single intraperitoneal administration of tin (II) tartrate to albino rats (2 mg $\text{Sn}{}^{\mathrm{++}}\text{100}\text{g}$ body wt) depressed the levels of hepatic glutathione reductase, glucose-6-phosphate dehydrogenase, lactate dehydrogenase, succinic dehydrogenase, reduced glutathione (GSH) and total sulfhydryl contents and led to an elevated level of tin. Serum aminotransferase levels were however, not affected but an increase in serum bilirubin and calcium levels was noticed.$\text{In}$$\text{vitro}$ studies showed that tin tartrate upto a concentration of 2 uM did not affect the activity of liver enzymes tested, when the enzyme preparations were incubated with metallic salts during the time of assay. The critical concentration of tin for these parameters was at 5 uM.     

Distribution of radiotin (Sn) in partially hepatectomised rats and its binding with subcellular components of liver cells

Distribution of radiotin (Sn¹¹³) in target organs and in the hepatic subcellular fractions was studied in sham and partially hepatectomised rats 72 hrs after the administration of tin (II) tartrate (2 mg Sn⁺⁺, 10 uCi/100 gm body weight) intraperitoneally. The results indicate that in both the groups Sn¹¹³ was maximally accumulated in liver followed by kidney and spleen. Partially hepatectomised rat however accumulated less Sn¹¹³ in liver while an increase was observed in kidney. Subcellular studies showed significantly high affinity of tin for microsomes. A compartmental shift of radiotin from cytosol to microsomal fraction was observed in hepatectomised rats when compared to sham operated rats.     

Adsorption in combination with ozonation for the treatment of textile waste water: a critical review

Intrusion of synthetic textile dyes in the ecosystem has been recognized as a serious issue worldwide. The effluents generated from textiles contain large amount of recalcitrant unfixed dyes which are regarded as emerging contaminants in the field of waste water study. Removal of various toxic dyes often includes diverse and complex set of physico-chemical, biological and advanced oxidation processes adopted for treatment. Adsorption in itself is a well-known technique utilized for treatment of textile effluents using a variety of adsorbents. In addition, ozonation deals with effective removal of dyes using high oxidising power of ozone. The review summarizes dye removal study by a combination of ozonation and adsorption methods. Also, to acquire an effective interpretation of this combined approach of treating wastewater, a thorough study has been made which is deliberated here. Results assert that, with the combined ability of ozone and a catalyst/adsorbent, there is high possibility of total elimination of dyes from waste water. Several synthetically prepared materials have been used along with few natural materials during the combined treatment. However, considering practical applicability, some areas were identified during the study where work needs to be done for effective implementation of the combined treatment.

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