Use Of Nitrogen-based Fertilizers Research Articles

Nitrate Contamination in the Groundwater and Associated Human Health Risk Assessment for Gaya District, Bihar, India

The study pertains to nitrate concentration in groundwater resources of the Gaya district, Bihar, India and its related health risk to the local population. Groundwater serves as the principal source of drinking water in the area. 40 representative groundwater samples were collected and analyzed for nitrate and other water quality parameters. The concentration of Nitrate (NO3 -) in the groundwater of Gaya district varied from 1.62 to 155.6 mg/L and exceeded the Bureau of Indian Standards (BIS) permissible limits for drinking water in 30% of the samples. The elevated nitrate levels were predominantly attributed to agricultural activities. To evaluate the human health risks associated with groundwater, Hazard Quotient for nitrate (HQnitrate) were calculated using the United States Environmental Protection Agency method. The mean HQnitrate values were estimated to be 1.03, 0.89 and 1.65 for the male, female and child populace, respectively depicting considerable risk to male and child populace. In 67.5% of the samples, HQnitrate for children exceeded the safety threshold of 1. The study advocates significant health risks, especially to children in many parts of Gaya district due to high concentrations of nitrate in the groundwater. Judicial use of nitrogen-based fertilizers is suggested to prevent further contamination of groundwater.

Role of reactive nitrogen species in changing climate and future concerns of environmental sustainability.

The nitrogen (N) cycle is an intricate biogeochemical process that encompasses the conversion of several chemical forms of N. Given its role in food production, the need for N for life on Earth is obvious. However, the release of reactive nitrogen (Nr) species throughout different biogeochemical processes contributes to atmospheric pollution. Several human activities generate many species, including ammonia, nitrous oxide (N2O), nitric oxide, and nitrate. The primary reasons for this change are the use of nitrogen-based fertilizers, industrial activities, and the burning of fossil fuels. N2O poses a significant threat to environmental sustainability on our planet, with its global warming potential approximately 298 times greater than that of CO2. It has direct or indirect impacts on the environment, agroecosystem, and human life on earth. Solar, hydroelectric, geothermal, and wind turbines must be used to reduce Nr emissions. In addition, enterprises should install catalytic converters to minimize nitrogen gas emissions. To reduce Nr emissions, strategic interventions like fertilizer balancing are needed. This work will serve as a comprehensive guide for researchers, academics, and policymakers. Additionally, it will also assist social workers in emphasizing the Nr issue to the public in order to raise awareness within worldwide society.

Effect of Carbon Footprint on Agricultural Productivity in Nigeria: An Empirical Analysis

This study examines the relationship between carbon footprint (CFP) components and agricultural productivity in Nigeria, a critical area of investigation given the country's reliance on agriculture for economic stability, food security, and employment. Using time series data from 1990 to 2020, sourced from the Central Bank of Nigeria (CBN) and the World Bank, this study analyzes the effect of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) emissions on agricultural output. Employing Robust Least Square (RLS) regression and the Error Correction Model (ECM), the study finds that CO2 and CH4 emissions negatively affect agricultural productivity, with 1% increases in CO2 and CH4 emissions leading to approximate decreases in agricultural output by 2% and 3%, respectively. Conversely, a 1% increase in N2O emissions correlates with an 8% increase in agricultural output, attributed to the use of nitrogenbased fertilizers. The results confirm the presence of long-run equilibrium relationships among the variables, with approximately 32% of the previous year's disequilibrium corrected annually. The study's findings align with the Environmental Kuznets Curve (EKC) hypothesis, suggesting that Nigeria is in the early stages of economic growth where environmental degradation is pronounced. These insights underscore the need for sustainable agricultural practices and effective carbon emission mitigation strategies to enhance food security and support economic growth in Nigeria.

Morphological and Transcriptomic Analyses Reveal the Toxicological Mechanism and Risk of Nitrate Exposure in Bufo gargarizans Embryos.

In recent years, nitrate (NO3-N) pollution in water bodies has been increasing due to the excessive use of nitrogen-based fertilizers. Exposure to NO3-N during the development of amphibian embryos may have lasting effects on the growth and development of individuals and even threaten their survival, but the toxicity mechanism of NO3-N in amphibian embryos prior to thyroid morphogenesis remains unclear. In the present study, Bufo gargarizans was selected as the model organism to investigate the toxic effects of 10 mg/L and 100 mg/L NO3-N exposure (N10 and N100) on amphibian embryos using methimazole (MMI) and exogenous thyroxine (T4) as the reference groups. We found that T4, MMI, N10 and N100 inhibited B. gargarizans embryo growth and development, with MMI and N100 showing the earliest and strongest effects. Transcriptome analysis revealed that MMI and NO3-N (especially N100) significantly downregulated genes related to thyroid morphogenesis and cholesterol metabolism, while upregulating genes related to inflammation and apoptosis. Together, these results contribute to a deeper understanding of the complex mechanisms by which NO3-N disrupts B. gargarizans embryonic development, reveal the potential risks of NO3-N pollution to other aquatic organisms, and provide insights into the conservation of a broader ecosystem.

An Integrated Framework to Assess the Environmental and Economic Impact of Fertilizer Restrictions in a Nitrate-Contaminated Aquifer

Groundwater nitrate contamination caused by the excessive use of nitrogen-based fertilizers has been widely recognized as an issue of significant concern in numerous rural areas worldwide. To mitigate nitrate contamination, corrective management practices, such as regulations on fertilizer usage, should be implemented. However, these measures often entail economic consequences that impact farmers’ income, and thus should be properly assessed. Within this context, an integrated framework combining the environmental and economic assessment of fertilization restrictions through multi-criteria decision analysis is presented in an effort to efficiently manage groundwater nitrate contamination in rural areas. For this task, various scenarios involving reductions (10%, 20%, 30%, 40% and 50%) in fertilizer application were investigated, evaluated and ranked in order to determine the most suitable option. The environmental assessment considered occurrences of nitrates in groundwater, with a specific emphasis on nitrate concentrations in water-supply wells, as obtained by a nitrate fate and transport model, while the economic analysis focused on the losses experienced by farmers due to the reduced fertilizer usage. Our case-study implementation showed that a 30% reduction in fertilization is the most appropriate option for the area being studied, highlighting the importance of adopting such an approach when confronted with conflicting outcomes among alternatives.

Air pollution monitoring: development of ammonia (NH<sub>3</sub>) dynamic reference gas mixtures at nanomoles per mole levels to improve the lack of traceability of measurements

Abstract. The measurement of ammonia (NH3) in ambient air is a sensitive and priority topic due to its impact on ecosystems. NH3 emissions have continuously increased over the last century in Europe because of intensive livestock practices and the enhanced use of nitrogen-based fertilizers. European air quality monitoring networks monitor atmospheric NH3 amount-of-substance fractions. However, the lack of stable reference gas mixtures (RGMs) of atmospheric amount-of-substance fractions of ammonia to calibrate NH3 analyzers is a common issue of the networks, which results in data that are not accurate, traceable, or, thus, geographically comparable. In order to cover this lack, LNE (Laboratoire National de Métrologie et d'Essais) developed, in close collaboration with the company 2M PROCESS, a gas reference generator to dynamically generate NH3 RGMs in air. The method is based on gas permeation and a further dynamic dilution to obtain an amount-of-substance fractions ranging between 1 and 400 nmol mol−1 (also well known as ppb or parts per billion; 1 ppb (NH3) to ≈ 0.7 µg m−3) to cover the amount-of-substance fractions of ammonia measured in ambient air (emissions) and the operating range of the NH3 analyzers used by the monitoring networks. The calibration of the elements of the generator against the LNE primary standards ensures the traceability of the RGMs to the international system of units. Furthermore, the highly accurate flow and oven temperature measurements of the reference generator, together with the associated calibration procedure defined by LNE, guarantee relative expanded uncertainties of the calibration of the NH3 analyzers that are lower than 2 % (coverage factor = 2). This result is very satisfactory, considering the low NH3 amount-of-substance fraction levels (1 to 400 nmol mol−1) and the phenomena of adsorption and desorption, especially in the presence of traces of water on contact surfaces. A bilateral comparison was organized between METAS (Swiss Federal Institute of Metrology) and LNE, which consisted of the calibration of a Picarro G2103 gas analyzer by both national metrology institutes (NMIs). The results highlighted the good agreement between the NH3 reference generators developed by the two institutes and allowed the validation of both LNE's reference generator and calibration procedure. Since the end of 2020, LNE has calibrated several NH3 analyzers from the French air quality monitoring networks (Associations Agréées de Surveillance de la Qualité de l'Air – AASQA) using the newly developed SI-traceable RGMs. The enhanced number of calibrations provided may increase the comparability, accuracy, and traceability of the NH3 measurements carried out on French territory.

Wheat Breeding, Fertilizers, and Pesticides: Do They Contribute to the Increasing Immunogenic Properties of Modern Wheat?

Celiac disease (CD) is a small intestinal inflammatory condition where consumption of gluten induces a T-cell mediated immune response that damages the intestinal mucosa in susceptible individuals. CD affects at least 1% of the world’s population. The increasing prevalence of CD has been reported over the last few decades. However, the reason for this increase is not known so far. Certain factors such as increase in awareness and the development of advanced and highly sensitive diagnostic screening markers are considered significant factors for this increase. Wheat breeding strategies, fertilizers, and pesticides, particularly herbicides, are also thought to have a role in the increasing prevalence. However, less is known about this issue. In this review, we investigated the role of these agronomic practices in depth. Our literature-based results showed that wheat breeding, use of nitrogen-based fertilizers, and herbicides cannot be solely responsible for the increase in celiac prevalence. However, applying nitrogen fertilizers is associated with an increase in gluten in wheat, which increases the risk of developing celiac-specific symptoms in gluten-sensitive individuals. Additionally, clustered regularly interspaced short palindromic repeats (CRISPR) techniques can edit multiple gliadin genes, resulting in a low-immunogenic wheat variety that is safe for such individuals.

The Quorum Sensing Auto-Inducer 2 (AI-2) Stimulates Nitrogen Fixation and Favors Ethanol Production over Biomass Accumulation in Zymomonas mobilis.

Autoinducer 2 (or AI-2) is one of the molecules used by bacteria to trigger the Quorum Sensing (QS) response, which activates expression of genes involved in a series of alternative mechanisms, when cells reach high population densities (including bioluminescence, motility, biofilm formation, stress resistance, and production of public goods, or pathogenicity factors, among others). Contrary to most autoinducers, AI-2 can induce QS responses in both Gram-negative and Gram-positive bacteria, and has been suggested to constitute a trans-specific system of bacterial communication, capable of affecting even bacteria that cannot produce this autoinducer. In this work, we demonstrate that the ethanologenic Gram-negative bacterium Zymomonas mobilis (a non-AI-2 producer) responds to exogenous AI-2 by modulating expression of genes involved in mechanisms typically associated with QS in other bacteria, such as motility, DNA repair, and nitrogen fixation. Interestingly, the metabolism of AI-2-induced Z. mobilis cells seems to favor ethanol production over biomass accumulation, probably as an adaptation to the high-energy demand of N2 fixation. This opens the possibility of employing AI-2 during the industrial production of second-generation ethanol, as a way to boost N2 fixation by these bacteria, which could reduce costs associated with the use of nitrogen-based fertilizers, without compromising ethanol production in industrial plants.

Urease and Nitrification Inhibitors—As Mitigation Tools for Greenhouse Gas Emissions in Sustainable Dairy Systems: A Review

Currently, nitrogen fertilizers are utilized to meet 48% of the total global food demand. The demand for nitrogen fertilizers is expected to grow as global populations continue to rise. The use of nitrogen fertilizers is associated with many negative environmental impacts and is a key source of greenhouse and harmful gas emissions. In recent years, urease and nitrification inhibitors have emerged as mitigation tools that are presently utilized in agriculture to prevent nitrogen losses and reduce greenhouse and harmful gas emissions that are associated with the use of nitrogen-based fertilizers. Both classes of inhibitor work by different mechanisms and have different physiochemical properties. Consequently, each class must be evaluated on its own merits. Although there are many benefits associated with the use of these inhibitors, little is known about their potential to enter the food chain, an event that may pose challenges to food safety. This phenomenon was highlighted when the nitrification inhibitor dicyandiamide was found as a residual contaminant in milk products in 2013. This comprehensive review aims to discuss the uses of inhibitor technologies in agriculture and their possible impacts on dairy product safety and quality, highlighting areas of concern with regards to the introduction of these inhibitor technologies into the dairy supply chain. Furthermore, this review discusses the benefits and challenges of inhibitor usage with a focus on EU regulations, as well as associated health concerns, chemical behavior, and analytical detection methods for these compounds within milk and environmental matrices.

Cotton Plantations in India: The Environmental and Social Challenges

Cotton, one of the principal cash crops of India, contributes significantly to the country’s economy and foreign exchange earnings. Approximately 60 million people depend on cotton production and related industries for their livelihoods. Although India has the largest cotton plantation area, in terms of yield, it is far behind. Even though cotton occupies only five percent of India’s total cultivable land, approximately 50 percent of pesticides used in India are consumed by the cotton cultivation, causing environmental pollution and health hazard. The use of nitrogen-based fertilizers further increases the problem. Many social issues such as child labor, women labor, extremely small landholdings and unviable livelihoods are associated with cotton plantations. Recently, due to the norms set up by the textile importing countries, these issues have assumed great importance. This article, after giving a brief introduction to the cotton plantation sector in India, will deal with the environmental and social challenges of the cotton plantations.

Macadamia Nutshell Biochar for Nitrate Removal: Effect of Biochar Preparation and Process Parameters

Agricultural runoff is a major cause of degradation to freshwater sources. Nitrate is of particular interest, due to the abundant use of nitrogen-based fertilizers in agricultural practices globally. This study investigated the nitrate removal of biochar produced from an agricultural waste product, macadamia nutshell (MBC). Kinetic experiments and structural analyses showed that MBC pyrolsed at 900 °C exhibited inferior NO3− removal compared to that pyrolsed at 1000 °C, which was subsequently used in the column experiments. Concentrations of 5, 10 and 15 mg/L, with flowrates of 2, 5 and 10 mL/min, were examined over a 360 min treatment time. Detailed statistical analyses were applied using 23 factorial design. Nitrate removal was significantly affected by flowrate, concentration and their interactions. The highest nitrate removal capacity of 0.11 mg/g MBC was achieved at a NO3− concentration of 15 mg/L and flowrate of 2 mL/min. The more crystalline structure and rough texture of MBC prepared at 1000 °C resulted in higher NO3− removal compared to MBC prepared at 900 °C. The operating parameters with the highest NO3− removal were used to study the removal capacity of the column. Breakthrough and exhaustion times of the column were 25 and 330 min respectively. Approximately 92% of the column bed was saturated after exhaustion.

Fabrication of smart magnetic nanocomposite asymmetric membrane capsules for the controlled release of nitrate

Nitrate contamination of water resources due to excessive use of nitrogen-based fertilizers has become a global health issue. In this work, a recyclable and environmentally sensitive magnetic Fe2O3/PES (Polyethersulfone) nanocomposite asymmetric membrane like capsules (NAMCs) were prepared such that release nitrate in a controlled manner. Different characterization techniques such as SEM, EDAX, DSC, and surface energy measurement were used to systematically characterize the NAMCs. It was observed that the incorporation of only 0.5wt.% Fe2O3 nanoparticles into NAMC provided a slow and steady release rate of nitrate. A further addition of nanoparticles (from 0.5wt.% to 1.5wt.%) into the capsules matrix resulted in an increase in the initial-release rate (IRR, from 3.17 to 4.17μS/cmmin) and maximum release level (MRL, from 36 to 52μS/cm). The designed capsules also showed recyclability and the ability to respond to the environmental conditions. For instance, IRR increased from 3.17 to 5.31μS/cmmin for NAMCs when temperature increased only by 10°C. These findings could be considered as a new and green approach to prevent nitrate contamination of water resources in the first place without exacerbating energy issues. Although this work is based on the controlled release of nitrate as the water resources contaminant, the NAMCs can also be used for other nutrients and fertilizers.

Molecular and phenotypic characterization of transgenic wheat and sorghum events expressing the barley alanine aminotransferase.

The expression of a barley alanine aminotransferase gene impacts agronomic outcomes in a C3 crop, wheat. The use of nitrogen-based fertilizers has become one of the major agronomic inputs in crop production systems. Strategies to enhance nitrogen assimilation and flux in planta are being pursued through the introduction of novel genetic alleles. Here an Agrobacterium-mediated approach was employed to introduce the alanine aminotransferase from barley (Hordeum vulgare), HvAlaAT, into wheat (Triticum aestivum) and sorghum (Sorghum bicolor), regulated by either constitutive or root preferred promoter elements. Plants harboring the transgenic HvAlaAT alleles displayed increased alanine aminotransferase (alt) activity. The enhanced alt activity impacted height, tillering and significantly boosted vegetative biomass relative to controls in wheat evaluated under hydroponic conditions, where the phenotypic outcome across these parameters varied relative to time of year study was conducted. Constitutive expression of HvAlaAT translated to elevation in wheat grain yield under field conditions. In sorghum, expression of HvAlaAT enhanced enzymatic activity, but no changes in phenotypic outcomes were observed. Taken together these results suggest that positive agronomic outcomes can be achieved through enhanced alt activity in a C3 crop, wheat. However, the variability observed across experiments under greenhouse conditions implies the phenotypic outcomes imparted by the HvAlaAT allele in wheat may be impacted by environment.

Assessment of nitrate contamination of groundwater using lumped-parameter models

In this paper, lumped-parameter models (LPMs) were developed and utilized to simulate nitrate concentration in the groundwater of Gaza City and Jabalia Camp (GCJC) in the Gaza Coastal Aquifer (GCA) in Palestine. In the GCJC area, nitrate levels exceed the maximum contaminant level (MCL) of 10 mg/L NO 3-N (45 mg/L NO 3) in many wells. Elevated nitrate concentrations in the groundwater of GCJC area are due to the disposal of untreated wastewater, the existence of heavy agriculture in the surrounding areas, and the use of cesspits for wastewater disposal. The developed LPMs utilize monthly time steps and take into consideration all the sources and sinks of water and nitrate in the study area. The main outcomes of the LPMs are the average temporal water table elevation and nitrate concentration. In order to demonstrate LPMs usability, a set of management options to reduce nitrate concentration in the groundwater of the study area were proposed and evaluated using the developed LPMs. Four broad management options were considered where these options tackle the reduction of nitrate concentration in the lateral inflow, rehabilitation of the wastewater collection system, reduction in cesspit usage, and the restriction on the use of nitrogen-based fertilizers. In addition, management options that encompass different combinations of the single management options were taken into account. Different scenarios that correspond to the different management options were investigated. It was found based on the LPMs that individual management options were not effective in meeting the MCL of nitrate. However, the combination of the four single management options with full rehabilitation and coverage of the wastewater collection network along with at least 60% reduction in both nitrate concentration in the lateral inflow and the use of nitrogen-based fertilizers would meet the MCL constraint by the end of the management period.

Escalating Worldwide use of Urea – A Global Change Contributing to Coastal Eutrophication

While the global increase in the use of nitrogen-based fertilizers has been well recognized, another change in fertilizer usage has simultaneously occurred: a shift toward urea-based products. Worldwide use of urea has increased more than 100-fold in the past 4 decades and now constitutes >50% of global nitrogenous fertilizer usage. Global urea usage extends beyond agricultural applications; urea is also used extensively in animal feeds and in manufacturing processes. This change has occurred to satisfy the world's need for food and more efficient agriculture. Long thought to be retained in soils, new data are suggestive of significant overland transport of urea to sensitive coastal waters. Urea concentrations in coastal and estuarine waters can be substantially elevated and can represent a large fraction of the total dissolved organic nitrogen pool. Urea is used as a nitrogen substrate by many coastal phytoplankton and is increasingly found to be important in the nitrogenous nutrition of some harmful algal bloom (HAB) species. The global increase from 1970 to 2000 in documented incidences of paralytic shellfish poisoning, caused by several HAB species, is similar to the global increase in urea use over the same 3 decades. The trend toward global urea use is expected to continue, with the potential for increasing pollution of sensitive coastal waters around the world.

Biological nitrogen fixation and future challenges of agriculture. The endophytic connection.

Feeding the growing global population, anticipated to be 8 billion by the year 2020, is one of the most important recent challenges of agriculture. The increase in cereal grain yield, to cope with this demand, directly implies a dramatic increase in the use of nitrogen-based fertilizers and agrochemicals. Some of these intensive agricultural practices have progressive detrimental effects on the environment. This review is focused on some novel insights gained into the understanding of associative and symbiotic interactions of plants with nitrogen-fixing organisms that makes Biological Nitrogen Fixation (BNF) a viable answer to this compelling dilemma.

Impact of suburbanization on ground water quality and denitrification in coastal aquifer sediments

The South Carolina coastal plain is currently facing rapid population growth and suburbanization. Suburbanization brings the potential for surface- and ground water contamination from the use of nitrogen-based fertilizers, which can render water toxic to humans and fish, and lead to eutrophication. Additionally, nitrate is highly mobile in sediments and poses the potential for contamination of receiving waters, downstream areas, and ground water. The objectives of this study were to evaluate the differences in ground water quality and sediment denitrification rates at two sites, an undeveloped forested area (Oyster Creek, North Inlet, SC) and an area which has been developed for residential and commercial use (Dog Creek, Murrells Inlet, SC). Ground water monitoring wells were installed at the two sites at several sampling depths ranging from 0.6 m to 5 m. Ground water samples were collected every 4–8 weeks for 16 months, and analyzed in the field for pH, conductivity, temperature, and dissolved oxygen (DO), and in the laboratory for nitrate, nitrite, ammonia, phosphate and total organic carbon (TOC). Additionally, sediment samples were collected from two locations in both creek bottoms from approximately 1.0 m depth, and microbial denitrification was estimated using the acetylene block technique by measuring the accumulation of nitrous oxide (N 2O). Ground water at both sites was microaerophilic, ranging from 0.4 to 1 mg O 2/l. Ammonia and TOC concentrations were significantly higher at the forested site due to higher inputs of organic matter in the form of leafy vegetation, whereas nitrate concentrations were significantly higher at the suburban site. Sediments from both sites were able to rapidly convert NO 3 to N 2O with progressive depletion of NO 3 in extracted sediments. Both the rate of N 2O production and the conversion efficiencies were found to increase with increasing nitrate concentrations from 0.1 to 0.5 mg/g. The smallest nitrate concentration had the lowest N 2O production and NO 3 conversion efficiency. However, for the intermediate treatment (0.25 mg/g) conversion efficiencies were variable. In addition to potential increased NO 3 inputs, increased drainage for development present at suburban sites may cause aeration of near channel soils and favor the oxidized, more mobile form of nitrogen. Because the suburban site has steeper hydraulic gradients, and nitrate is highly mobile, there is potential for both nitrate transport to the estuary and accumulation in the shallow water-table aquifer at the suburban site. However, it appears that the microbial communities from both sites were well adapted to denitrifying inputs of nitrate in the concentration ranges tested.