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A limiting factor in land application of sewage sludge is the resultant heavy metal accumulation in soils followed by biomagnification in the food chain, posing a potential hazard to animal and human health. In view of this fact, pot experiments were conducted to evaluate the effect of digested sludge application to soil on phytotoxicity of heavy metals such as Cd, Cr, Ni, and Pb to radish (Raphanus sativus L.) plants. Increasing sludge levels resulted in increased levels of DTPA-extractable heavy metals in the soil. Cadmium was the dominant metal extracted by DTPA followed by Ni, Pb, and Cr. The extractability of metals by DTPA tended to decrease from the first to the second crop. Dry matter yield of radish increased significantly as a function of increasing sludge treatments. Soil application of sludge raised the concentration of one or more heavy metals in plants. Shoots contained higher concentrations of Cd, Cr, and Ni than the roots of radish plants. Shoot concentrations of Cd, Cr, Ni, and Pb were within the tolerance levels of this crop at all rates of sludge application. Shoot as well as root concentration of Cd was above 0.5 mg kg −1 , considered toxic for human and animal consumption. The levels of DTPA-extractable Cd and Ni were less correlated while those of Cr and Pb were more correlated with their respective shoot and root contents. The results emphasize that accumulation of potentially toxic heavy metals in soil and their build-up in vegetable crops should not be ignored when sludge is applied as an amendment to land.

Climate change imprints on soil are projected primarily through the changes in soil moisture and surge in soil temperature and CO2 levels in response to climate change and is anticipated to have varying impacts on soil characteristics and processes that are instrumental in the restoration of soil fertility as well as productivity. Climate change encompasses a major concern of sharing its impact on the stability and functionality of soil microbiome and is characterized by one or more chief stability metrics encircling resistance, resilience, and functional redundancy. Nevertheless, the explorations over the past years have unveiled the potential of microbial interventions in the regeneration of soils or assurance of perked-up resilience to crops. The strategies involved therein encompass harnessing the native capability of soil microbes for carbon sequestration, phyto-stimulation, bio fertilization, rhizo-mediation, biocontrol of plant pathogens, enzyme-mediated breakdown, antibiosis, prompting of anti-oxidative defense mechanism, exudation of volatile organic compounds (VOCs) and induced systemic resistance (ISR) response in the host plant. However, the short storage and shelf-life of microbe-based formulations stay a significant constraint and rigorous efforts are necessary to appraise their additive impact on crop growth under changing climate scenarios.

show that during the whole period, average PM 1 concentrations ranged from 15.10 to 108.9 µg/m 3 , PM 2.5 (28.70-577.50 µg/m 3 ), PM 4 (44.50-780.87 µg/m 3 ), PM 10 (57.13-1225.53 µg/m 3 ), total suspended particulates (77.77-1410.27 µg/m 3 ) and CO 2 (332.4-655.0 ppm). The average concentrations of these parameters showed that the maximum PM 1 concentration was found at Dalgate (53.77 µg/m 3 ) and PM 2.5 had its maximum average concentration at Jehangir Chowk (140.13 µg/m 3 ). Other parameters like PM 4 , PM 10 , TSP and CO 2 had a maximum average values at Jehangir Chowk (240.23 µg/m 3 , 633.40 µg/m 3 , 853.50 µg/m 3 and 533.20 ppm, respectively). The pollution load was observed to be maximum during winter season followed by autumn, summer and spring. The lowest concentration of all pollutants except CO 2 was observed in April 2020 and this might be due to COVID-19 lockdown observed in the country during the same period.

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Use of wastewater for a variety of purposes is gaining increased popularity as a means of preserving scarce freshwater resources and nutrient recycling particularly in developing countries A field experiment was carried out to evaluate the growth and yield of Capsicum annum var. Nishat-1 under irrigation with different concentrations of domestic wastewater (grey and black water) in combination with recommended dose of fertilizers(RDF). This field experiment was carried out for two consecutive years Kharief 2012-2013 and involved 6 treatments (T1–T6) with three replications in RCBD. Before being utilized, wastewater was stabilized for 20-25 days in open containers. The highest yield (288.12 q ha-1 ) was recorded in T1 (Recommended dose of fertilizers =RDF) followed by 283.49 q ha-1 in T4 (50% grey water and 50% RDF ), 275.92 q ha-1 in T5 (50% black water 50% RDF) , 270.03 q ha-1 in T2 (100% grey water), 260 q ha-1 in T6 (50% black water and 50% grey water) and least of 251.96 q ha-1 in T3 (100% black water) . The data also reveals that the concentrations of the various physico-chemical parameters (viz., pH, EC, OC, N, P, K, Ca, Mg, Cu, Fe, Mn, Zn, Cd, Ni, Cr, Pb) of waste water and pre and post experiment soil samples were within permissible limits. Quality parameters viz total soluble salts, ascorbic acid, chl-a, chl-b, total-chl, carbohydrates and protein content between various treatments exhibited different trends. This study shows that there is an option for recycling of stabilized waste water in agriculture.

Background: Potassium (K) availability in soil and plant uptake is restrained by the dynamic interactions among the different pools of K. Aims: To understand these interactions, a study was undertaken to assess the quantity–intensity (Q/I) and buffering characteristics of rainfed maize (Zea mays L.) growing soils. Ten contrasting soils were evaluated for K partitioning changes in exchangeable K (ΔEK) and non‐exchangeable K (ΔNEK) pools in the soil‐solution phase and buffering characteristics using a modified version of Q/I approach. Results: The partitioned Q/I isotherms showed strong adsorption with the increase in K concentration ratio (CRK) and the changes due to ΔEK were higher than changes due to ΔNEK. Total buffering capacity (PBCK) significantly correlated (r = 0.92, p <0.01) with clay content with a major share contributed by buffering capacity owing to non‐exchangeable K ( PBCΔNEK K ) rather than exchangeable K ( PBCΔEK K ). The fixation capacity (β) factor, the magnitude of added K converted into a non‐exchangeable pool, ranged from 41 to 63%, whereas release (α) factor, the magnitude of added K converted to the exchangeable pool, ranged from 19 to 36%. Both threshold solution K (CKr) and threshold exchangeable K (EKr) values were found to be high in Satran clay loam (S2) and lower in Doon silty clay loam (S3) soils. The equilibrium exchangeable K (EKo) was found close to minimum exchangeable K (Emin) in Doon silty clay loam (S3) and Babaweyl sandy clay loam (S1) soils and overall Emin constituted about 8.94 to 0.57% of the EKo. Conclusion: It may be concluded that K Q/I isotherm partitioning provides a valuable insight to assess the dynamic relations. The ratio of α/β (K recharge index) could be used to evaluate the K enrichment capacity of soil to K additions while EKr and Emin can be potentially useful in the elucidation of exchangeable K as K fertility index especially in soils with poor K fertilizer management.

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