2005

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Biomonitoring of air pollution in a seasonally dry tropical suburban area using what transplants
(Springer Netherlands, 2005) Madhu Rajput; Madhoolika Agrawal
Air pollution has been identified as a serious problem throughout the world which causes tremendous loss to the crops by affecting plant growth and yield. Earlier, air pollution was restricted to urban and industrial regions. Over the last few decades, however, it has become evident that pollutants can be transported over long distances and hence their impact may be felt widely over rural areas. The present study was conducted to evaluate the impact of urban air pollution on suburban agriculture with respect to the changes in photosynthetic rate, stomatal conductance, water-use efficiency, plant height, numbers of tillers, leaves, ears and seeds, chlorophyll, carotenoid, protein, phenol, ascorbic acid, nitrogen and sulphate-sulphur contents and seed weight of pot-grown wheat plants (Triticum aestivum var. HUW 468) kept at different sites around Varanasi city receiving varying levels of pollution load. Mean concentrations of SO2, NO2 and O3 were monitored. The study clearly showed that plants are negatively affected by the ambient levels of air pollutants. Reduction in various parameters directly corresponded with the air pollution levels at different sites. © Springer Science + Business Media, Inc. 2005.
Amelioration of Indian urban air pollution phytotoxicity in Beta vulgaris L. by modifying NPK nutrients
(2005) Anoop Singh; S.B. Agrawal; Dheeraj Rathore
Air pollution levels are increasing at an alarming rate in many developing countries, including India and causing a potential threat to crop production. Field experiments were conducted to examine the impact of urban air pollutants on biomass (yield) and some physiological and biochemical parameters of palak (Beta vulgaris L. var. All Green) that grew from germination to maturity at seven periurban sites of Allahabad city having different concentrations of air pollutants under different levels of nutrients. The 6 h daily mean NO 2, SO 2 and O 3 concentrations varied from 2.5 to 42.5, 10.6 to 65 and 3.5 to 30.8 μg m -3, respectively at different locations. Levels of air pollution showed significant negative correlations with photosynthetic pigments, protein, ascorbic acid and starch contents and catalase activity of palak leaves. A significant negative correlation was found for total biomass with SO 2 (r = -0.92), NO 2 (r = -0.85) and O 3 (r = -0.91) concentrations. The increased fertilizer application (N, P and K) over the recommended dose resulted in a positive response by reducing losses in photosynthetic pigments and total biomass. This study proved that ambient air pollution of Allahabad city is influencing negatively to the growth and yield of palak plants. © 2004 Elsevier Ltd. All rights reserved.
Atmospheric depositions around a heavily industrialized area in a seasonally dry tropical environment of India
(2005) Raj Kumar Singh; Madhoolika Agrawal
Clear and throughfall bulk depositions were collected in the downwind of a highly industrialized region in Sonbhadra district of India to estimate the influence of anthropogenic activities on chemical composition of depositions. Significant spatial and temporal variations in depositions of cations and anions were observed. Depositions were higher near the thermal power stations and coalmines as compared to distantly situated site. Seasonally summer samples showed maximum cation and anion depositions followed by winter and minimum in rainy season. The mean pH of the depositions indicates that rainfall in the area is alkaline. Among the anions, maximum deposition was recorded for SO 42- followed by NO3- and minimum for Cl-. Among the cations, Ca2+ deposition was maximum followed by NH4+. Na+, K+ and Mg2+ deposition rates showed more or less similar values. The depositions of cations and anions as well as pH were higher in throughfall than clearfall samples. Results of the present study suggest that atmospheric depositions are strongly modified due to thermal power stations and coal mines in the area. © 2005 Elsevier Ltd. All rights reserved.
Effects of air pollution on agriculture : An issue of national concern
(2005) Madhoolika Agrawal
The problem of air pollution has attracted special attention in India due to tremendous increase in size of population, industrialization and urbanization since last few decades. The major air pollutants of concern are identified as sulphur dioxide, nitrogen dioxide, ozone and particulate matter. Thermal power plants and transport sector is the biggest contributor of air pollution in the country. Ambient air around large industrial sources and metropolitan cities has already shown pollutant levels above the standards set by Central Pollution Control Board. India. Experimental studies conducted at Varanasi situated in upper Gangetic plains of India have indicated significant losses of agricultural production at current ambient pollutant levels in urban, suburban and rural areas. The intensity of losses, however, depends upon the pollutant concentration, duration of exposure, climatic and edaphic factors, plant species and cultivars. Pollutants either affect the plants directly by causing visible injury or indirectly growth or yield reductions without visible injury. Reductions in leaf area, biomass, chlorophyll, ascorbic acid and N contents have often been observed for the crop species growing in polluted area. Field transect studies have shown significant negative correlations between air pollutant concentrations and net photosynthesis, biomass accumulation and yield of crop plants. Monocot plants are found to be more resistant than dicot plants. Leguminous plants and leafy vegetables are most sensitive to air pollutants among the crop plants. Winter crops showed relatively lower magnitude of yield losses at different sites than summer crops. Quality of seeds also varied between urban, suburban and rural sites. Variations in nutrient, metabolite and energy contents of seeds directly corresponded to the levels of air pollutants at different sites. At urban and suburban sites, the magnitude of response involved all pollutants, whereas at rural site ozone had more influence. Ozone seems to play a major role in yield loss as maximum reductions in yield and quality of seeds were recorded at sites showing highest O3 concentrations. Simulation experiments conducted in closed top or open top chambers have also confirmed the adverse impacts of individual pollutants on plants. National ambient air quality standards are mainly based on health impact, hence a revision of the same taking into account climatic conditions; type of vegetation and soil is urgently required to save crops from adverse impacts of air pollution. Economic evaluation of crop loss due to air pollution is an important need of the future to secure food for growing population of the country. Long-term studies are required all along the country to identify the high and low risk zones of air pollution in different regions to develop control policy for reducing adversities of air pollution on vegetation.

2005

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