Use Of Fertilizers In Agriculture Research Articles

Appraisal of groundwater quality from Sirpur Kaghaznagar area,Adilabad district, Telangana

Ground water quality plays an important role in promoting agricultural production and standard of human health and the sources and causes of ground water pollution are closely associated with human use of water. For many years ground water was thought to be protected from contamination by the layers of rocks and soil that acts as a filter, but contaminants do make their way into the ground water and affect its quality. The present paper deals with the assessment of seasonal variation in ground water and its suitability for drinking purpose. For this purpose major ions were assessed and Water Quality index was calculated for both pre monsoon and post monsoon season. A comparison of ground water quality in relation to drinking water quality standards proves that the ground water quality was altered with respect to parameters such as pH, EC, TDS, Ca2+, Mg2+ and TH showcased higher levels. Similarly WQI calculated for both the seasons ranged to fall in poor to unsuitable category. From the above results it is clear that the ground water of the study area is deteriorated due to paper industry effluents, use of agricultural fertilizers and the local geology and is found unsatisfactory for drinking purpose.

Hydrogeochemical characterization and groundwater quality assessment in the intensive agricultural zone of the Upper Cheliff plain, Algeria

The alluvial aquifer of Upper Cheliff (northern Algeria) is known for its intensive agricultural activities, which is based especially on groundwater exploitation. This aquifer is now facing a dual problem of quantity and quality, with a decrease in the groundwater levels and an increase in mineralization. Twenty monitoring samples were collected and analyzed for major ion during the dry season 2014. In the present study, we try to characterize the hydrogeochemical processes and to assess the impact of natural and anthropogenic conditions on groundwater mineralization. The analytical results of the dry season 2014 show a groundwater quality slightly alkaline (pH > 7) and indicate that the majority of samples have a values exceeding the limits of potability fixed by WHO in 2008, due to the various sources of anthropogenic pollution. The Piper diagram shows the dominance of groundwater types: Ca–Cl, the mixed facies (Cl–SO4–Ca–Mg), and Ca–HCO3: The mineralization process in this aquifer is mainly controlled by the lithology of the aquifer (exchange water–rock and weathering of calcareous crust dissolution in the unsaturated zone), by anthropogenic factors (discharges of untreated urban sewage, intensive use of fertilizers in agriculture and the use of domestic septic tanks by rural inhabitants) and also by geoclimatic conditions (semiarid climate). Suitability of groundwater shows more than 80% of samples have very poor quality for drinking and more than 20% of samples indicate a quality unsuitable for irrigation.

Research of indicators of the endogenous antioxidant system in rats affected with sodium nitrite on the background of tobacco intoxication

Under conditions of progression of environmental pollution, the one of priority directions of toxicology and medicine is the study of features and mechanisms of the combined effect of xenobiotics – risk factors of many ecologically depending diseases. In last years there is widely studied the influence of tobacco smoking on the human organism. The numerous researches proved that the wide use of mineral fertilizers in agriculture resulted in environmental pollution, especially pollution of atmospheric air, drinking water and food and created the real threat for life of both human and other living beings. All these anthropogenic toxicants penetrate the human organism and lead to the oxidative stress and activation of free radical processes in the organism and imbalance in functioning of pro- and antioxidant systems.The aim of the research is to establish the level of the oxidative stress and activity of indicators of the system of antioxidant defense in rats, injured with sodium nitrite on the background of 45 days tobacco intoxication for choosing adequate schemes of correction of detected disorders.Experiments were realized on non-linear white male rats of different age groups, who underwent the effect of tobacco smoke during 45 days. Two groups of animals, injured by smoke, received sodium nitrite in dose 45 mg / kg of body mass for 24 hours and 72 hours before the end of experiment. Euthanasia was realized under thiopental anesthesia. Blood, blood serum liver and kidneys were taken for the study.For determining AOF, there was realized extraction of blood neutrophils by the method of gradient centrifugation. For measuring AOF level in neutrophils, dichlofluorescein diacetate was used. The level of AOF production was analyzed by the intensity of dye stuff lighting on the current cytometer. Catalase activity in the reaction with ammonium molybdate, superoxide dismutase activity with nitrotetrazolium blue, the content of restored glutathione at interaction of Ellman reagent with free SH-groups were determined in blood serum and tissues. The content of ceruloplasmin in blood serum was determined by the reaction of para-phenylendiamine oxidation.The studies were realized observing general principles of experiments on animals, coordinated with statements of the European convention about protection of vertebral animals, used for experimental and other scientific aims.Rats of all age groups, injured by tobacco smoke demonstrated the increase of AOF level in blood that resulted in the oxidative process development in the organism. The synchronous intoxication of rats with tobacco smoke and sodium nitrite deepened even more all detected disorders that testify to the reliable (p≤0,05) increase of AOF that acquired the maximal values in immature animals. The oxidative stress, observed in the organism of rats of all age groups, caused inhibition of antioxidant enzymes activity: superoxide dismutase, catalase and decrease of the non-enzyme component of the antioxidant system – restored glutathione. The synchronous injure of animals by sodium nitrite and tobacco smoke resulted in the decrease of catalase activity in lungs of mature rats in 2,4times compared with intact animals in the final term of the study. After sodium nitrite intoxication of rats, toxicated by smoke, the content of restored glutathione was maximally decreased in the liver of mature rats (in 4,5 times). Most expressed changes of indicators of the antioxidant system were observed in blood serum and organs of mature rats

Use of anthropogenic nitrogen fertilizers in agriculture is associated with per capita ethanol consumption

It has previously been demonstrated that emissions of the agricultural pollutant, nitrous oxide (N2O), may be a confounder to the relationship between herbicide use and psychiatric impairments, including ADHD. This report attempts to extend this hypothesis by testing whether annual use of anthropogenic nitrogen-based fertilizers in U.S. agriculture (thought to be the most reliable indicator of environmental N2O emissions) is associated with per capita ethanol consumption patterns, a behavior often comorbid with ADHD. State estimates of anthropogenic nitrogen fertilizers from the United States Geological Survey (USGS) were obtained for the years between 1987 and 2006. Our dependent variable was annual per capita ethanol consumption. Ethanol consumption was categorized as beer, wine, spirits, and all alcoholic beverages. Least squares dummy variable method using two-ways fixed effects was utilized. Among states above the 50th percentile in farm use of anthropogenic nitrogen for all years (i.e., agricultural states), a one log-unit increase in farm use of anthropogenic nitrogen fertilizers is associated with a 0.13 gallon increase in total per capita ethanol consumption (p<0.0125). No statistically significant association between farm use of anthropogenic nitrogen and per capita ethanol consumption was found in states below the 50th percentile in farm use of anthropogenic nitrogen. The new findings are in agreement with both behavioral human studies demonstrating a link between N2O preference and alcohol and drug use history as well as molecular studies elucidating shared mechanisms between trace N2O antinociception and alcohol-seeking related behaviors.

FREE RADICALS AND INFLAMMATION IN RATS OF DIFFERENT AGE IN CASES OF SODIUM NITRITES AND TOBACCO SMOKE POISONING

Background. Due to the wide use of nitrate fertilizers in agriculture and their migration into groundwater and food, the spreading of nitrate poisoning has become epidemic. However, people in the process of life get into bad habits: smoking, alcohol, drugs abuse. All these factors affect health and can cause fatal outcome. In real life, people are often exposed to more toxic factors that lead to general poisoning of the body and damage of many organs.Objective. The research was aimed to study the activity of free radicals and inflammation in rats of different age in cases of sodium nitrite affection with underlying 45-day tobacco intoxication.Methods. The content of nitrite ion (NO2-) was evaluated by Gris reaction. The level of pro-inflammatory (interleukin 6 (IL-6) and anti-inflammatory (interleukin 4 (IL-4) cytokines was determined in serum by ELISA method using test kits.Results. It was proved that in rats of different age affected by sodium nitrite with underlying 45-day tobacco smoke intoxication, the content of nitrite ion in serum, liver, lungs and myocardium is increased. After poisoning the animals with the studied toxicants, inflammation was activated in the body that was evidenced by the increased pro-inflammatory cytokine IL-6 and decreased inflammatory cytokine IL-4 in serum.Conclusions. The nitrite ion content in organs was the most significant and inflammation was manifested in the immature rats. In these animals the content of anti-inflammatory cytokines was the lowest.

Effect of nitrogen management modes on grain yield, nitrogen use efficiency and light use efficiency of wheat

A nitrogen management experiment with three nitrogen levels (0, 120, and 180 kg·hm-2, namely N0, N120, N180) and three nitrogen allocation modes (NA: base fertilizer 100%; NB: base fertilizer 70% + seedling fertilizer 30%; NC: base fertilizer 60% + jointing fertilizer 40%) was conducted at four sites (Chongqing, Renshou, Guanghan and Xichang) during two consecutive years, the SPAD value, canopy photosynthetic rate (CAP), photosynthetically active radia-tion (PAR) interception efficiency and grain yield were determined, and the nitrogen use efficiency and PAR use efficiency were calculated. The results showed that the SPAD of upper-most three leaves, CAP, PAR interception efficiency and grain yield were promoted with increasing nitrogen fertilizer, but nitrogen fertilizer use efficiency, productivity efficiency, uptake efficiency and use efficiency were decreased. The promoting effects of nitrogen fertilizer postponing were different among nitrogen levels, with the highest SPAD in N180 treatment and the highest CAP in N120 treatment. The light use efficiency of different nitrogen fertilization patterns differed among four sites. Furthermore, nitrogenous fertilizer postponing significantly increased nitrogen agricultural fertilizer use efficiency, productivity efficiency, uptake efficiency and apparent nitrogen recovery efficiency, but declined nitrogen use efficiency, and the performance of NC was better than NB. Among different sites, Guanghan had the highest SPAD, CAP, PAR interception efficiency and grain yield, Xichang had higher SPAD and nitrogen use efficiency, lower CAP and PAR use efficiency, Chongqing and Renshou had the lowest SPAD, light use efficiency, nitrogen use efficiency and grain yield. Biomass had significant positive relationships with grain yield, CPA, SPAD, and PAR interception efficiency. Therefore, the increase of nitrogen fertilizer could promote yield at all sites, and nitrogenous fertilizer postponing could further optimize grain yield component and improve nitrogen and light use effi-ciency. But the effects depended on the years and sites, thus a target nitrogen management mode should be site-specifically made.

Relationships Between Land Use and Stream Nutrient Concentrations in a Highly Urbanized Tropical Region of Brazil: Thresholds and Riparian Zones.

Nutrient enrichment in streams due to land use is increasing globally, reducing water quality and causing eutrophication of downstream fresh and coastal waters. In temperate developed countries, the intensive use of fertilizers in agriculture is a main driver of increasing nutrient concentrations, but high levels and fast rates of urbanization can be a predominant issue in some areas of the developing world. We investigated land use in the highly urbanized tropical State of Rio de Janeiro, Brazil. We collected total nitrogen, total phosphorus, and inorganic nutrient data from 35 independent watersheds distributed across the State and characterized land use at a riparian and entire watershed scales upstream from each sample station, using ArcGIS. We used regression models to explain land use influences on nutrient concentrations and to assess riparian protection relationships to water quality. We found that urban land use was the primary driver of nutrient concentration increases, independent of the scale of analyses and that urban land use was more concentrated in the riparian buffer of streams than in the entire watersheds. We also found significant thresholds that indicated strong increases in nutrient concentrations with modest increases in urbanization reaching maximum nutrient concentrations between 10 and 46% urban cover. These thresholds influenced calculation of reference nutrient concentrations, and ignoring them led to higher estimates of these concentrations. Lack of sewage treatment in concert with urban development in riparian zones apparently leads to the observation that modest increases in urban land use can cause large increases in nutrient concentrations.

Actual versus environmentally recommended fertilizer application rates: Implications for water quality and policy

Excessive application of crop nutrients has been identified as a threat to surface water quality in many jurisdictions. The Western Basin of Lake Erie Collaborative Agreement commits the governments of Michigan, Ohio and Ontario to reduce phosphorus entering the Lake Erie’s western basin by 40% by 2025/2026 from 2008 levels by, among other things, reducing fertilizer use in agriculture. The International Joint Commission (2014) estimates that agriculture accounts for 44% of total phosphorus loadings to Lake Erie. Our study uses a unique micro level data set of 16 farms over 6 years that allows us to examine 397 individual nutrient application choices at the field and farm level. If efforts to reduce excessive application of nutrients are to be successful at aggregate level, they need to be informed by an understanding of how farmers make nutrient application decisions within existing production systems. The study aims to enhance our understanding by determining whether farmers applying nutrients to maximize yields, to maximize net returns or to meet environmental targets, and whether over-application depends on factors such as farm size, crop type, manure use, and type of nutrient. We compare actual nutrient application rates with site specific rates intended to minimize excess nutrient application and we regress nutrient application levels against potential explanatory variables including farm size, crop rotation practices, and application of livestock. The data were collected from farmers in the Gully Creek watershed in Ontario. We found that excess nutrient applications, as a percentage of the total nutrient applications, are much higher for phosphorus than for nitrogen and higher for wheat than for corn. While most of the farmers in the study are not required to comply with provincial nutrient management regulations, many of them apply fertilizer at rates close to that recommended by those regulations and some at rates significantly less. While most farms are applying fertilizer, particularly nitrogen, at rates close to the minimum crop requirements, nevertheless, a few farms apply much more phosphorous than recommended. Policy and research efforts should be directed toward targeting these individuals that appear to be the primary contributor to the nutrient loading issue.

Searching for Nitrogen-Fixing Microorganisms: An Original, Relevant, and Successful Early Research Experience

A five-week research project was designed as part of a summer internship for high school students, and could also be used with educators or in introductory undergraduate research courses. This is a guided-inquiry-based project, framed within the significant issue of supplementing fertilizer use in agriculture with nitrogen-fixing microorganisms. This experience exposes students to how scientists are studying real-world problems; it teaches them basic research techniques, and promotes inquiry-based learning in a real research environment. It also fills a current gap in K-12 education that lacks enough microbiology emphasis. Research interns collect soil samples from various fields and use culture-dependent and culture-independent techniques to test whether there are nitrogen-fixing microorganisms that can be isolated and identified in each soil sample. Students work in a research laboratory making nitrogen-free media; culturing, isolating, and identifying microorganisms; extracting soil DNA; and amplifying the 16S rRNA and nifH genes. We administer a pre-test and a post-test, and students present their research both in a short talk and with a poster. By hosting high school students in a research laboratory and immersing them in laboratory science, we hope to inspire them to pursue a STEM-related career.

Point and nonpoint pollution and restoring groundwater quality in Italy: 30 years of experience

In Italy, a significant portion of the drinking water supply is provided by groundwater, hence also the importance given to its protection. For nonpoint pollutants, the paper describes the experimental approach (field trials) and cartographic materials (vulnerability maps) used to assess the nitrogen dynamics and the consequent presence of nitrates in groundwater. In the high vulnerability areas, there are limitations on the use of agricultural fertilizers, while in urban areas, various interventions on water discharges must be undertaken. Little information is available from the monitoring network with regard to emerging pollutants. For point pollutants in contaminated sites, an estimate is given of the distribution of the most frequently found substances; after a detailed description of these substances, possible remediation technologies are discussed. Despite the recovery of the mass of pollutants even as much as 90–99%, the cleanup values (expected concentrations expressed as µg/L) established by national legislation have not been achieved. It can be stated that the scientific community is considering the new paradigm expressed by the “order of magnitude of the flow of pollutant mass” to replace the old paradigm consisting in the “limit value of final concentrations”.

Spatial Appraisal of Problems and Prospects of Fertilizer Use for Agriculture on the Environment in Mbieri, Mbaitoli Local Government Area, Imo State Nigeria

This study appraises the spatial problems and prospects of fertilizer use in agriculture on the Environment in Mbieri, Mbaitoli Local Government Area of Imo State. Structured questionnaires were sampled in each villages randomly selected from the seven autonomous communities of Amaike-Mbieri, Awo Mbieri, Ezi-Mbieri, Ihitte Isi-Mbieri, Obazu Mbieri, Obi-Mbieri and Umueze-Mbieri for collection of data. The data were analysed using descriptive statistical tools of tables, charts and graphs. The outcome showed that 71.2% of the farmers do not have University Education. All the kinds of fertilizer in use in the study area contain Nitrogen with NPK 20-10-10 the most sought-after. Findings show that 54% of the farmers prefer the application of fertilizer NPK for replenishing lost soil nutrients while, 60% of the Farmers in the study area use surface broadcast method in application of fertilizer NPK on their farms. However, it was observed from this research that majority of this nitrogen compounds are washed down through surface runoffs causing pollution and eutrophication of the Ecosystems and water bodies. Government should set up research centre for Fertilizer use in Agriculture where farmers can be equipped with adequate knowledge of the best way to use fertilizer NPK while sustaining the environment.

Comparison of Natural Radioactivity of Commonly Used Fertilizer Materials in Egypt and Japan

Specific activities of 238U, 232Th, and 40K in the environment have been redistributed by the use of fertilizers in agriculture so their concentrations in fertilizer materials should be measured to identify the safe utilization of fertilizers. In the present work, the specific activities of these radionuclides in five commonly used fertilizers in Egypt and five fertilizers used in Japan were measured by HPGe and γ-ray spectrometry. The average values of 238U, 232Th, and 40K in Japanese fertilizers were less than their values in Egyptian fertilizers but both had some samples with specific activities greater than the recommended limiting values. The radiological hazards of radium equivalent activity (Raeq), external (Hex) and internal (Hin) indexes, alpha and gamma indexes, and annual effective dose, due to the presence of these radionuclides, were calculated and compared with each other.

Origin of the Salinity in the Coastal Aquifer of La Paz, Mexico

Coastal areas are attractive places for the establishment of urban settlements owing to the many benefits in terms of quality of life. An example of these areas is La Paz in Southern Baja California, Mexico, where demographic growth and agricultural activities under dry climatic conditions are threatening the availability of water resources. In recent years, an increasing salinity of groundwater has been identified, however, the origin of the salinity is not clear. Near the coastline, salt water intrusion is considered to be the main factor, while others play a role for increased salinities in the middle and upper aquifer zone. The study, using a hydrochemical tool analysis shows that the salinity of the coastline is the result of over-exploitation of wells, which increases saline intrusion resulting in a reverse cation exchange. It also indicates that the salinization of water in the recharge area is product of carbon dioxide dissolution and weathering of rock-forming silicate minerals, and in the central part result from cycling and use of fertilizer in agriculture.

Ақдaлa aлқaбының топырaғының қaзіргі зaмaнғы экологиялық жaғдaйы

The article discusses the influence of presowing flooding of irrigated rice array on the seasonal dynamicsof soil processes. As well as the characteristic of negative processes and their consequences thatarise after the flooding of rice soils of the array, for example: lack of oxygen, harmful effects of hydrogensulfide in the rice culture.The paper describes the current ecological state takyr soils Akdalaarray degradation and waterloggingof soils. These processes are consequences of depressed economic conditions and the use of pesticidesand fertilizers in agriculture. In the last desyatiletiya in connection with the deterioration of reclamationcondition of irrigated soils in the arrays significantly decreased the fertility continues dehumification andecological condition of soils. In some regions of Kazakhstan, much of the land unusable due to salinity.Of the above environmental issues affect the reduction of humus, nutrients, physico-chemical andbiological properties of soil, which in turn affects productivity and quality of rice. This article describesthe environmental problems of Kazakhstan soils associated with zatuplenie array. The study of the influenceof presowing flooding of irrigated rice array on the seasonal dynamics of soil processes is veryimportant for our country.The analysis of literary sources shows that in the rice areas of the Republic has developed an environmentallyunfavorable situation. This reduces the potential for socio-economic development of theRepublic, particularly, the resource base of the rural economy. In this regard, of particular urgency isthe creation of a scientific and theoretical foundations of the holistic concept of fertility reproduction ofperiodically flooded soils.

Groundwater nitrate pollution and human health risk assessment by using HHRA model in an agricultural area, NE China

In order to learn the pollution circumstance of groundwater nitrate detailedly in Songnen Plain of Northeast China and estimate its potential risk to human health of local residents, a total of 389 groundwater samples were collected in 2014 and studied from residential areas and public water supply wells in 11 cities and counties in southeastern of Songnen Plain. The analysis results showed that the spatial distributions of main chemical components in groundwater had great variations with statistical concentrations in the order of TDS> HCO3> Ca> NO3> Cl> Na> SO4> Mg> K> NH4> NO2. As for NO3, it ranged from less than 0.02mg/L to 497mg/L with an average value of 39.46mg/L indicating an obviously anthropogenic pollution. Even more than 32% of the samples exceeded the Grade III threshold (20mg/L of N) according to China's standard. The results obtained from principal component analysis showed that high NO3 concentration could be attributed to human activities, especially the excessive use of chemical fertilizers in agriculture. Further, a human health risk assessment (HHRA) model derived from the US Environmental Protection Agency (USEPA) was applied to estimate the potential health risk of groundwater nitrate considering both drinking water and dermal contact pathways. The results indicated that potential health risks of adult males and females within about 60% of the area were at the acceptable level, while those within about 40% were beyond the acceptable level. The area at the acceptable level for children covered 49% of the total area while the same value for infants was 37%. The NO3 concentration in southeast and northeast of the study area was the highest so that residents in these regions were at the highest health risk. In conclusion, risk levels for different crowds in the study area varied obviously, generally in the order of infants> children> adult females> adult males, and the potential health risks of residents, especially minors and rural residents, should cause enough attention both from the society and the academic community.

Degradation of water quality: the case of plain west of Annaba (northeast Algeria)

AbstractIn the world, the water quality is undergoing deterioration due to urban and industrial wastes, and intensive use of chemical fertilizers in agriculture. Unfortunately, as in most countries of the world, Algeria is experiencing a severe crisis of its environment apart from the problem of depletion of water resources. The plain west of Annaba is particularly subjected to a general industrial pollution. The pollution problem in this region has really started to become worrying not earlier than in 1980, when the economic crisis has led some industrial units to sacrifice the “Environment” criterion for the benefit of the production. We were particularly interested in this work in waters of the superficial aquifer and wadis like Boudjemaa, Bouhdid, Sidi Harb, and Forcha whose waters are most often used to irrigate the surrounding agricultural land. Comparison of analytical results from two periods – 2006–2016 for the: EC, pH, Ca2+, Mg2+, Cl−, NO2 and 2006–2010 for the: Fe, Cr, Cu2+, Pb+ show a degradation of water quality in this region, which represents a very vulnerable area with a risk to pollution of groundwater.

Effect of nitrates in drinking water on the prevalence of thyroid cancer and other thyroid diseases: a literature review and post-Chernobyl research experience in Belarus

Nitrate content in the groundwater of Belarus has increased dramatically due to intensive use of nitrogen fertilizers in agriculture. Research performed during the post-Chernobyl period showed that the increased incidence of thyroid cancer is affected both by the level of nitrates in the groundwater and the radiation dose to which the thyroid was exposed.

Fertilizantes agrícolas aplicados via solução nutritiva em Cattleya labiata Lindl

Fertilization through nutrient solution is commonly used in commercial production of potted flowers, being employed soluble NPK formulations. However, most commercial formulations available in the market have high costs and the use of agricultural fertilizers can be an economically viable alternative. The objective of this study was to evaluate the effectiveness of agricultural fertilizers applied as nutrient solutions, in replacement of commercial formulations, on initial growth of Cattleya labiata. C. labiata seedlings in vitro propagated were grown in a greenhouse with controlled temperature, 27 ± 2° C, and retaining 50% brightness. Polypropylene pots were used with 0.415 L capacity, containing a mixture of pine bark and charcoal (1:1, v:v) as substrate. Altogether were used 4 treatments: without fertilization (control); Peters® - NPK 20 20 20 (3.0 g L -1 ); NPK - urea (1.3 g L -1 ), superphosphate (3.3 g L -1 ) and potassium chloride (1.0 g L -1 ); NK - urea (1.3 g L -1 ) and potassium chloride (1.0 g L -1 ). The nutrient solutions were applied 50 ml per pot every two weeks, according to the treatments. Were evaluated phytometric characteristics, pH and electrical conductivity of the substrate beyond the levels and accumulation of macronutrients. The experimental design was completely randomized with 12 replications, being considered each pot with two plants as an experimental unit. The parameters were submitted to ANOVA and Tukey’s test at 5% probability. Regarding phytometric parameters no significant differences were observed between the treatments that received fertilization, which are superior to the control in height and dry mass of shoots. The more accumulated nutrients were K&gt;Ca&gt;N, in the treatments that received fertilization. The use of urea, superphosphate and potassium chloride, applied in nutrientsolution, have potential to replace the commercial formulations in the initial growth of native orchid Cattleya labiata.

Modeling the impact of nitrate fertilizers on groundwater quality in the southern part of the Nile Delta, Egypt

The use of fertilizers in agriculture in Egypt, especially nitrogen, has increased significantly in the last decade, resulting in nonpoint contamination of the groundwater resources. This study investigated the effect of using nitrogen fertilizer on groundwater contamination with nitrate in the central southern part of the Nile Delta. NO3− concentrations in shallow groundwater were assessed based on the applied urea dose (the common nitrogen fertilizer used) in year 2014. A groundwater modeling system (GMS) comprising MODFLOW and MT3D was used to simulate the three-dimensional groundwater flow and NO3− transportation processes in El-Menoufia Governorate, located in the central region of the Nile Delta aquifer. Calibration for MODFLOW was conducted to match known head configurations to minimize the water balance differences. Calibration of MT3D was accomplished by fitting the model to the measured NO3− concentrations during the year 2014. The results highlighted areas of groundwater contamination by NO3−, which occurred at shallow depths (40 m) due to the significant loads of nitrogen fertilizer application and the flood irrigation method. While the results suggested one approach was to avoid using contaminated shallow groundwater as a water source, a more sustainable approach would be to implement best management practices to reduce and control the amount of nitrate leaching into the shallow groundwater system in the future.

UNDERSTANDING THE BEHAVIOUR OF CONTAMINATION SPREAD IN NAGARJUNA SAGAR RESERVOIR USING TEMPORAL LANDSAT DATA

LANDSAT images are used to identify organic contaminants in water bodies, but, there is no enough evidence in present literature that LANDSAT is also good in identifying a mixture of organic and mineral contaminants such as agricultural waste. The focus of this paper is to evaluate the effectiveness of LANDSAT imagery to identify organic and mineral contamination (OMC) and to identify spread extent variations of pollution over the season/year in the Nagarjuna Sagar (NS) reservoir using only satellite images. A new band combination is proposed in order to detect OMC, because existing formulae based on band ratio proved to be inadequate in detecting the contamination in NS. Difference in reflectance values of Red and Green channel of an image helps clearly distinguish clear water from OMC water. This procedure was applied over LANDSAT data of the calendar years 2008, 2014 and 2015 to understand the contamination spread pattern through the reservoir. Results show that contamination is following a similar pattern over these calendar years. In January contamination starts at inlets and by May contamination spreads to almost 90% of the reservoir when the total area of water spread is also reduced by half. Contamination spread is low during the monsoonal period of June to September due to heavy inflow and heavy outflow of waters from NS reservoir. Post monsoon NS is contaminated again because of heavy inflow of runoffs from neighboring land use and limited water outflow. This contamination spread pattern matches the agricultural seasons and fertilizer application pattern in this region, indicating that agricultural use of fertilizers could be one of the primary causes of contamination for this waterbody.