Browsing by Author "M. Agrawal"

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A comparison of North American and Asian exposure-response data for ozone effects on crop yields
(2009) L.D. Emberson; P. Büker; M.R. Ashmore; G. Mills; L.S. Jackson; M. Agrawal; M.D. Atikuzzaman; S. Cinderby; M. Engardt; C. Jamir; K. Kobayashi; N.T.K. Oanh; Q.F. Quadir; A. Wahid
Modelling-based studies to assess the extent and magnitude of ozone (O3) risk to agriculture in Asia suggest that yield losses of 5-20% for important crops may be common in areas experiencing elevated O3 concentrations. These assessments have relied on European and North American dose-response relationships and hence assumed an equivalent Asian crop response to O3 for local cultivars, pollutant conditions and climate. To test this assumption we collated comparable dose-response data derived from fumigation, filtration and EDU experiments conducted in Asia on wheat, rice and leguminous crop species. These data are pooled and compared with equivalent North American dose-response relationships. The Asian data show that at ambient O3 concentrations found at the study sites (which vary between ∼35-75 ppb 4-8 h growing season mean), yield losses for wheat, rice and legumes range between 5-48, 3-47 and 10-65%, respectively. The results indicate that Asian grown wheat and rice cultivars are more sensitive to O3 than the North American dose-response relationships would suggest. For legumes the scatter in the data makes it difficult to reach any equivalent conclusion in relative sensitivities. As such, existing modelling-based risk assessments may have substantially underestimated the scale of the problem in Asia through use of North American derived dose-response relationships. © 2009 Elsevier Ltd. All rights reserved.
Air pollutant concentrations in Varanasi, India
(1992) J. Pandey; M. Agrawal; N. Khanam; D. Narayan; D.N. Rao
This study reports the diurnal patterns in the concentrations of ozone (O3), nitrogen dioxide (NO2), sulphur dioxide (SO2) and total suspended particulate matter (TSP) in the urban atmosphere of Varanasi city in India during 1989. The city was divided into five zones and three monitoring stations were selected in each zone. Ambient concentrations of NO2 and SO2 were maximum during winter but ozone and TSP concentrations were highest during summer. The measured maximum concentrations (2-h average) were 150 and 231 μg m-3 (0.078 and 0.086 ppm) for NO2 and SO2, respectively, for the winter season. Ozone and TSP concentrations reached a maximum of 160 (0.08 ppm) and 733 μg m-3, respectively, in the summer. NO2 and SO2 concentrations peaked in the morning and evening. Peak concentrations of O3 occurred in the afternoon, generally between noon and 4 p.m. Maximum concentrations of O3, NO2, SO2 and TSP were measured in zones I and II, and minimum in zone V. © 1992.
Air pollution acclimation potential of Carissa carandas L.
(1993) J. Pandey; M. Agrawal
[No abstract available]
Air pollution tolerance index of plants
(1991) S.K. Singh; D.N. Rao; M. Agrawal; J. Pandey; D. Naryan
In order to evaluate the susceptibility level of plants to air pollutants, four parameters, namely ascorbic acid, chlorophyll, relative water content, and leaf-extract pH, were determined and computed together in a formulation signifying the air pollution tolerance index (APTI) of plants. APTI values of 69 plant species, including herbs shrubs and trees, growing in the urban-industrial Lahartara region of Varanasi were estimated. Plants with a high index value were tolerant to air pollutants and vice-versa. On the basis of their indices, different plant groups were categorized into sensitive, intermediate, moderately tolerant plant groups were categorized into sensitive, intermediate, moderately gigantea, C. roseus, etc. were tolerant and D. sissoo, L. chinensis, C. carandus, C. rottleri, etc. were sensitive to air pollutant. The susceptibility level of plants to air pollution, as indicated through their index values, compared well with the responses of plants observed under laboratory and field experiments. The APTI determination provides a reliable method for screening sensitive/tolerant plants under field conditions where the air-shed is contamined by a variety of pollutants. © 1991 Academic Press Limited.
Antioxidants and growth regulators counter the effects of O3 and SO2 in crop plants
(1992) E.H. Lee; G.F. Kramer; R.A. Rowland; M. Agrawal
Antioxidant compounds such as ethylenediurea (EDU); N-[2-(2-oxo-1-imidazolidinyl) ethyl]-N′-phenylurea have been found to be effective in suppressing O3-induced leaf injury. Gibberellic acid (GA) inhibitors such as paclobutrazol, tetcyclaics and flurprimidol suppress visible SO2-induced injury. Antioxidant compounds are relatively ineffective in protecting plants from SO2-induced injury, while GA inhibitors are ineffective in protecting plants from O3 injury. EDU and GA inhibitors do not alter the stomatal behavior, however they can induce resistance to air pollutants stress. Furthermore, EDU and paclobutrazol (PP333) do not alter foliar membrane lipid composition. EDU does not alter polyamine composition. This suggests that the mechanism of plant tolerance to air pollutant exposure is probably biochemical rather than biophysical. Free radical scavenging enzymes or endogenous antioxidant compounds are more important than stomatal restriction of pollutant diffusion to the sensitive leaf mesophyll sites. © 1992.
Assessment of yield losses in tropical wheat using open top chambers
(2007) R. Rai; M. Agrawal; S.B. Agrawal
The present study deals with the evaluation of effects of ambient gaseous air pollution on wheat (Triticum aestivum L. var. HUW-234) growing in a suburban area situated in eastern Gangetic plain of India, using open top chambers. Eight hourly air monitoring was conducted for ambient concentrations of SO2, NO2 and O3 in filtered chambers (FCs), non-filtered chambers (NFCs) and open plots (OPs). Various morphological, physiological and biochemical parameters were assessed during different developmental stages and finally yield parameters were quantified at the time of harvest. Mean concentrations of SO2, NO2 and O3 were 8.4, 39.9 and 40.1 ppb, respectively during the experiment in NFCs. Concentrations of SO2, NO2 and O3 reduced by 74.6%, 84.7% and 90.4%, respectively in FCs as compared to NFCs. Plants grown in FCs showed higher photosynthetic rate, stomatal conductance, chlorophyll content and Fv/Fm ratio as compared to the plants in NFCs and OPs. Lipid peroxidation, proline, total phenol and ascorbic acid contents and peroxidase activity were higher in plants grown in NFCs. There were improvements in morphological parameters of plants growing in FCs as compared to those in NFCs and OPs. Yield of plants also increased significantly in FCs as compared to those ventilated with ambient air (NFCs) or grown in OPs. During the vegetative phase, NO2 concentrations were higher than O3, but O3 became dominant pollutant during the time of grain setting and filling. The study concludes that O3 and NO2 are the main air pollutants in the sub-urban areas causing significant yield reductions in tropical wheat plants. © 2007 Elsevier Ltd. All rights reserved.
Biochemical and physiological responses of Rice (Oryza sativa L.) grown on different sewage sludge amendments rates
(2010) R.P. Singh; M. Agrawal
Using sewage sludge, a biological residue from sewage treatment processes, in agriculture is an alternative disposal technique of waste. To study the biochemical and physiological responses of Rice (Oryza sativa L.) grown on different sewage sludge amendments (SSA) rates a field experiment was conducted by mixing sewage sludge at 0, 3, 4.5, 6, 9, 12 kg m -2 rate to the agricultural soil. Rate of photosynthesis and stomatal conductance increased in plants grown at different SSA rate. Chlorophyll and protein contents also increased due to different SSA rates. Lipid peroxidation, ascorbic acid, peroxidase activity and proline content increased, however, thiol and phenol content decreased in plants grown at different SSA rates. The study concludes that for rice plant sewage sludge amendment in soil may be a good option as plant has adequate heavy metal tolerance mechanism showed by increased rate of photosynthesis and chlorophyll content and various antioxidant levels. © Springer Science+Business Media, LLC 2010.
Changes in soil characteristics around coal-fired power plants
(1995) Jyoti Singh; M. Agrawal; Deo Narayan
The impact of coal-fired power plant emissions on certain physical and chemical properties of the soil was studied. A significant increase in bulk density and a decrease in porosity were observed at the sites receiving higher pollution than the control site. Soil pH was mostly alkaline at the polluted sites. The organic carbon content of the soil increased with increasing pollution load. Thermal power plant emissions have led to significant increases in the soil sulphate sulphur and exchangeable calcium contents, while reducing significantly total nitrogen. Reduction in total-N was positively correlated with the N-mineralization rate. The changes in total and organic sulphur, exchangeable potassium, and available phosphorus contents of soil were not significant. Significant positive correlations were found between dust fall rate and exchangeable Ca2+ and K+ contents of the soil and between ambient SO2 concentrations and soil SO42--S contents. The values of trace elements such as Mn, Fe, Cd Cu, Pb, and Ni were higher at sites closer to thermal power plants. © 1995.
Changes in ultrastructure, photosynthetic abilities, and secondary metabolite due to individual and interactive effects of chromium and ultraviolet-B radiation in Adhatoda vasica
(Institute of Experimental Botany, ASCR, 2023) A. Pandey; D. Jaiswal; M. Agrawal; S.B. Agrawal
The study was executed to assess individual and interactive effects of elevated ultraviolet-B (eUV-B) radiation and chromium (Cr) on a medicinal plant Adhatoda vasica Nees. The experiment was conducted under field conditions involving control, Cr, eUV-B, and Cr+eUV-B treatments. The results showed that Cr content was the highest in roots as compared to other parts under Cr+eUV-B. Significant reductions in photosynthetic rate, intercellular CO2 concentration, and stomatal conductance were observed under all treatments with maximum under Cr+eUV-B. Chlorophyll (Chl) fluorescence parameters showed variable responses under Cr and Cr+eUV-B. Chl content showed reductions under all treatments whereas Chl a/b ratio and carotenoids showed increment under eUV-B and reductions under Cr and Cr+eUV-B. The ultrastructure of leaves showed changes in chloroplasts under treatments. Vasicine (medicinally important secondary metabolite) increased under treatments. Our study revealed that A. vasica showed variable responses towards individual and interactive stress of Cr and eUV-B. © The authors.
Changes in vegetation characteristics downwind of an aluminium factory in india
(1994) Deo Narayan; M. Agrawal; J. Pandey; Jyoti Singh
Vegetation characteristics were assessed at different distances downwind of an aluminium factory to elucidate changes in community attributes. The importance value index (1V1) of sensitive species decreased and those of tolerant species increased with the increasing pollution load around the factory. Plant community composition changed with distance from this source. Species richness and the Shannon-Weiner index increased with the increasing distance from the source, while concentration of dominance declined from 1 to 11 km. The similarity coefficient indicated that the third and fifth sites are closer to each other, and first and fourth sites are farthest. The shape of the species sequence vs. the IVI distribution curve slipped from the shape of log normal distribution at sites receiving higher pollution load. The woody layer is found to be more affected compared to the herbaceous layer. The aluminium factory impact was most pronounced up to 4 km downwind of the source. Data on ambient air quality were found to be directly related to the unfavourable changes in community attributes. © 1994 Annals of Botany Company.
Characterization of wet and dry deposition in the downwind of industrial sources in a dry tropical area.
(2001) R.K. Singh; M. Agrawal
An atmospheric deposition study was conducted in the downwind of Shaktinagar Thermal Power Plant (STPP), Renusagar Thermal Power Plant (RTPP), and Anpara Thermal Power Plant (ATPP), at Singrauli region, Uttar Pradesh (UP), India to characterize dry and wet deposition in relation to different pollution loading. During the study period, dry and wet depositions and levels of gaseous pollutants (SO2 and NO2) were estimated across the sites. Dry deposition was collected on a monthly basis and wet deposition on an event basis. Depositions were analyzed for pH, nitrate (NO3-), ammonium (NH4+), and sulphate (SO4(2-)) contents. Dry deposition rate both collected as clearfall and throughfall varied between 0.15 to 2.28 and 0.33 to 3.48 g m(-2) day(-1), respectively, at control and maximally polluted sites. The pH of dry deposition varied from 5.81 to 6.89 during winter and 6.09 to 7.02 during summer across the sites. During the rainy season, the mean pH of clear wet deposition varied from 6.56 to 7.04 and throughfall varied from 6.81 to 7.22. The concentrations of NO2 and SO2 pollutants were highest during the winter season. Mean SO2 concentrations varied from 18 to 75 g m(-3) at control and differently polluted sites during the winter season. The variation in NO2 concentrations did not show a pattern similar to that of SO2. The highest NO2 concentration during the winter season was 50 g m(-3), observed near RTPP. NO2 concentration did not show much variation among different sites, suggesting that the sources of NO2 emission are evenly distributed along the sites. The concentrations of NH4+, NO3-, and SO4(2-) ions in dry deposition were found to be higher in summer as compared to the winter season. In dry deposition (clearfall) the concentrations of NH4+, NO3-, and SO4(2-) varied from 0.13 to 1.0, 0.81 to 1.95, and 0.82 to 3.27 mg l(-1), respectively, during winter. In wet deposition (clearfall), the above varied from 0.14 to 0.74, 0.81 to 1.82, and 0.67 to 2.70 mg l(-1), respectively. The study clearly showed that both dry and wet depositions varied between the sites and season, suggesting significant impact of industrial activities in modifying the atmospheric input. The nonacidic deposition suggests that there is no threat of acidification of the receiving ecosystem at present.
Comparative Assessment of UV-B Priming on Vegetative and Reproductive Stages of Oat and Barley
(Springer, 2020) S. Singh; K. Rai; S.B. Agrawal; M. Agrawal
Barley and oat were irradiated with elevated UV-B (+ 3.6 kJ m−2 d−1; 280–315 nm) during the vegetative stage, and their performances were evaluated at the tillering and panicle development stages (PDS). Physiological and biochemical measurements revealed that barley and oat performed almost alike against UV-B at the tillering stage, but the stress imprints led barley to display better performance at the PDS. Chlorophyll content increased under elevated UV-B in both the test crops with a higher increase in barley. Also, efficient synthesis of UV-B-absorbing compounds, i.e. flavonoids and phenolics in barley at the PDS, protected the photosynthetic machinery. Both the crops showed stimulations in growth responses under elevated UV-B except for root length in oat at the PDS. At the PDS, the reduction in total biomass of oat was accompanied with increased biomass allocation to the root portion suggesting the limiting factor for growth was belowground. Results clearly showed that UV-B priming during the vegetative stage enhanced tolerance against stress at the PDS in barley, whereas oat showed recovery for most of the measured parameters except ascorbic acid and biomass. Therefore, improved plant tolerance against UV-B during the panicle growth in barley is meaningful for a higher productivity. © 2019, The National Academy of Sciences, India.
Direct and indirect impacts of climate change on wheat yield in the Indo-Gangetic plain in India
(Elsevier B.V., 2021) A.S. Daloz; J.H. Rydsaa; Ø. Hodnebrog; J. Sillmann; B. van Oort; C.W. Mohr; M. Agrawal; L. Emberson; F. Stordal; T. Zhang
The Indo-Gangetic Plain (IGP) is one of the main wheat-production regions in India and the world. With climate change, wheat yields in this region will be affected through changes in temperature and precipitation and decreased water availability for irrigation, raising major concerns for national and international food security. Here we use a regional climate model and a crop model to better understand the direct (via changes in temperature and precipitation) and indirect (via a decrease in irrigation availability) impacts of climate change on wheat yields at four sites spread across different states of the IGP: Punjab, Haryana, Uttar Pradesh and Bihar. The results show an increase in mean temperature and precipitation as well as maximum temperature during the growing season or Rabi season (November–April). The direct impact of climate change, via changes in temperature and precipitation, leads to wheat yield losses between −1% and −8% depending on the site examined. Then, the indirect impact of climate change is examined, considering the impact of climate change on water availability leading to a decrease in irrigation. In this case, the yield losses become significant and much higher, reaching −4% to −36% depending on the site examined and the irrigation regime chosen (6, 5, 3 or 1 irrigations). This work shows that the indirect impacts of climate change may be more detrimental than the direct climatic effects for the future wheat yields in the IGP. It also emphasizes the complexity of climatic risk and the necessity of integrating indirect impacts of climate change to fully assess how it affects agriculture and choose the adequate adaptation response. © 2021 The Authors
Diurnal and seasonal variations in air pollutant concentrations in a seasonally dry tropical urban environment
(1994) J. Pandey; M. Agrawal
Air quality monitoring of Varanasi city indicates a logarithmic normal distribution pattern of 2h mean concentrations of SO2, NO2 and O3. Ozone concentrations peaked from late morning to afternoon of summer and those of SO2 and NO2 during early morning and late evening of winter months. The coincidence in the timing of SO2 and NO2 peaks appears interesting from the biological perspectives. -Authors
Effect of air pollution on peri-urban agriculture: A case study
(Elsevier Ltd, 2003) M. Agrawal; B. Singh; M. Rajput; F. Marshall; J.N.B. Bell
Peri-urban agriculture is vital for the urban populations of many developing countries. Increases in both industrialization and urbanization, and associated air pollution threaten urban food production and its quality. Six hour mean concentrations were monitored for SO2, NO2 and O3 and plant responses were measured in terms of physiological characteristics, pigment, biomass and yield. Parameter reductions in mung bean (Vigna radiata), palak (Beta vulgaris), wheat (Triticum aestivum) and mustard (Brassica compestris) grown within the urban fringes of Varanasi, India correlated directly with the gaseous pollutants levels. The magnitude of response involved all three gaseous pollutants at peri-urban sites; O 3 had more influence at a rural site. The study concluded that air pollution in Varanasi could negatively influence crop yield. © 2003 Elsevier Ltd. All rights reserved.
Effect of different sewage sludge applications on growth and yield of Vigna radiata L. field crop: Metal uptake by plant
(2010) R.P. Singh; M. Agrawal
The aim of this study was to assess the suitability of sewage sludge use for mung bean {Vigna radiata L. cv. Malviya janpriya (HUM 6)} plants by evaluating the growth, and yield responses, nutritional quality and heavy metal accumulation at different sewage sludge amendment (SSA) rates. Sewage sludge amendment modified the physico-chemical properties of soil by decreasing pH and increasing organic carbon, total iron and heavy metals. Plants showed increments in shoot length, leaf area and total biomass at all SSA rates, but root length increased only up to 9 kg m-2 SSA rates. Plants grown at different SSA rates showed higher nutrients and heavy metals in seeds, but protein content declined. Sewage sludge application caused about 39, 76 and 60% more yield at 6, 9 and 12 kg m-2 treatments, respectively. Concentrations of Pb and Ni in grains were higher than the Indian permissible limits at and above 9 kg m-2 and of Cd at 12 kg m-2 SSA rates. The study suggests that SSA at a rate lower than 9 kg m-2 may be recommended due to better fertilizing value for soil and promoting mung bean yield. Higher rate of sewage sludge application leads to elevated accumulation of heavy metals in seeds, which limits the suitability for human consumption. © 2010 Elsevier B.V. All rights reserved.
Effect of enhanced UV-B radiation on biomass, net photosynthesis and pigments in four tropical legumes
(1996) Anupa Singh; M. Agrawal
Experiments were conducted under field conditions to assess the responses of four tropical leguminous plants (Vigna radiata L. (Wilczek) cv. PS-16, Phasedus mungo L. (Hepper) cv. Pant U-30, Gylcine max L. (Merr.) cv. Punjab 1 and Phaseolus mungo L. (Hepper) cv. Mash-48), to enhanced UV-B radiation. Ultraviolet-B radiation was supplied by 313 Q-panel UV-B lamps and corresponded to 15% O3 depletion at 25°N latitude. Ultraviolet-B radiation affected both photosynthesis and stomatal resistance of all four plants. Biomass decreased significantly due to UV-B exposure. Chlorophyll and flavonoids also declined due to UV-B exposure. Thus these tropical legumes were markedly sensitive to enhanced UV-B radiation.
Effect of industrial emission on atmospheric wet deposition
(2001) M. Agrawal; R.K. Singh
In order to quantify the role of industries on atmospheric depositions, wet depositions were collected at different sites in Singrauli area of Sonbhadra district, U.P., India. Rainwater samples were collected on event basis and were analyzed for pH and concentration of H+ ion, cations and anions. The monthly variations in rainwater pH clearly indicate that early rainfall is more alkaline and as rainy season proceeds rainwater showed lower pH. The pH of rain from June to September varied from 6.6 to 4.8 at most polluted locality. Among different cations, Ca2+ showed maximum concentration followed by NH4+,Na+, Mg2+ and then K+, whereas among anions sulphate concentration was maximum followed by nitrate and then chloride. A significant positive correlation observed between sulphate and accumulated rainfall suggests that the source of sulphate is mainly the industrial activities. While the negative correlations of other cations with accumulated rain suggest their additional sources in the area. The study clearly indicates that the abundance of alkaline substances reduces the acidity of wet depositions.
Effect of power plant emissions on plant community structure
(Kluwer Academic Publishers, 1994) Jyoti Singh; M. Agrawal; Deo Narayan
A field study was conducted around two coal-fired thermal power plants (TPP) to analyse the impact of their emission on the structure of herbaceous communities in a dry tropical area. Phytosociological studies reflected that Cassia tora, Cynodon dactylon and Dichanthium annulatum dominate at heavily polluted sites. Alsycarpus monilifer, Convolvulus pluricaulis, and Desmodium triflorum are uniformly distributed, whereas Paspalidium flavidum, Phyllanthus simplex, and Rungia repens are dominant at less polluted sites. On the basis of Importance Value Index, the species were classified as sensitive, intermediate and resistant to TPP emissions. Shannon-Wiener Index of species diversity, species richness and evenness were inversely related, whereas concentration of dominance was directly related to the pollution load in the area. Significant negative correlation between ambient SO2 concentration and species diversity suggested selective elimination of sensitive species from the heavily polluted sites. © 1994 Chapman & Hall.
Effect of tree plantations on the soil characteristics and microbial activity of coal mine spoil land
(2002) Raman Kumar Dutta; M. Agrawal
Soil characteristics and microbial activity of vegetated coal mine spoil land under plantations of five exotic tree species were assessed. The data obtained were compared with those of the bare overburden mine spoil and the native forest soils. The results showed an improved soil status under different plantation stands compared to bare overburden. The silt and clay particles in soil were higher among different plantation stands in comparison to bare overburden dump. Bulk density was highest in the plots of Casuarina equisetifolia and lowest in Gravellia pteridifolia plots. Soil moisture content was also higher under different plantations. Water holding capacity and soil moisture content were highest in the Eucalyptus hybrid plots. Organic carbon and total nitrogen concentrations were higher in the plantation stands in comparison to the bare overburden dumps. Available nitrogen (NO3 - N and NH4 - N) was highest in the plots of Eucalyptus hybrid in all the three seasons. Soil microbial biomass C, N and P were highest in the plots of Gravellia pteridifolia and lowest in Cassia siamea plots. The plantations enhanced the nutrient status of the degraded mine spoil land. The plant species varied in their ability to modify the soil properties of mine spoil. Among the tree species Eucalyptus hybrid, Acacia auriculiformis and Casuarina equisetifolia were found to be most suitable for the modification of spoil characteristics during the revegetation process.