Nutrient Losses Research Articles

Usual suspects meet mission impossible: Nutrient losses and effects of mitigation measures on a coastal catchment in the Baltic Sea region.

Eutrophication of coastal areas is a global problem. A full-scale coastal remediation project was initiated in Björnöfjärden bay in the Stockholm archipelago in 2011. Measures to reduce external nutrient inputs from the surrounding catchment (15 km2) targeted agriculture, on-site wastewater treatment facilities, and horse keeping. The effects were evaluated at 22 water quality monitoring stations over 11years (2012-2022) to determine temporal trends in nutrient concentrations, spatial correlations within and between monitored sub-catchments, and effects of individual mitigation measures at local and catchment scale. The effect of individual measures varied from no significant effect to significant nutrient decreases (21% reduction in dissolved P concentrations in one lime filter) or increases (11% higher concentrations in total P in one constructed wetland). However, few significant trends were detected at sub-catchment outlet stations. Tailored placement, design, dimensioning, and maintenance of implemented mitigation measures are needed to improve their nutrient retention effect.

Evaluating best management practices for nutrient load reductions in tile-drained watersheds of the Laurentian Great Lakes Basin: A literature review.

Tile drainage systems are extensively implemented across the Laurentian Great Lakes Basin (GLB) to enhance agricultural productivity on poorly drained soils. However, these systems substantially contribute to excess nutrient runoff, particularly phosphorus (P) and nitrogen (N), exacerbating eutrophication and harmful algal blooms in the Great Lakes. This literature review synthesized current knowledge on nutrient loadings from tile-drained agricultural watersheds and evaluated the effectiveness of various agricultural best management practices (BMPs) in mitigating nutrient losses in the GLB. Through a meta-synthesis of field and watershed scale monitoring and modeling studies and statistical analysis using Box-Whisker plots and Monte Carlo simulations, we assessed the nutrient reduction potential of representative BMPs, including cover cropping, nutrient management, controlled drainage, and constructed wetlands in tile-drained landscapes. Findings indicated that individual BMPs substantially reduced nutrient loadings, but the effectiveness of these BMPs depended on site-specific factors, including climate conditions, soil type, and drainage system design. Integrated approaches at field, edge-of-field, and watershed scales with a combination of multiple BMPs enhanced nutrient reduction benefits, aligning with regional water quality targets. The review also highlighted the challenges of climate change that may undermine BMP performance by altering precipitation patterns and increasing extreme weather events. To address these complexities, we proposed a framework for developing adaptive BMP scenarios tailored to specific watershed conditions, emphasizing the need for long-term monitoring and hydrologic model enhancements. This framework was designed to help policymakers, stakeholders, and farmers protect water quality and balance agricultural productivity in the GLB and similar agricultural regions globally.

Nutritional Quality of « Tchonron », a Cultural Sauce Made from Adenia cissampeloïdes and Hibiscus asper Leaves Cooked with and without Potash

Leafy vegetables are an essential component of food and health security in many African countries. The Senoufo people of northern Côte d'Ivoire are well known for their high consumption of leafy vegetables, especially in « Tchonron » sauce, a traditional and cultural food prized by the Senoufo for its nutritional and therapeutic value. Unfortunately, it remains little known and little consumed by the Ivorian population. Although databases on the composition of raw foods (leafy vegetables) are available, data on cooked foods in Côte d'Ivoire are still lacking. The aim of this study was to evaluate the nutritional potential of « Tchonron » sauce prepared from Adenia cissampeloïdes (STAC) and Hibiscus asper (STHA) leaves. To prepare the « Tchonron » sauce, the leafy vegetables were pre-cooked for 20 min with or without potash and then ground. Peanut powder was then added to the crushed leaves and cooked for 10 min. The resulting sauces were dried and the powders obtained were used for analysis according to standard dietary recommendations. The results showed an increase in ash content from STHA (10.64 ± 1.25%) to STHAP (12.32 ± 1.39%) and STAC (15.70 ± 0.20%) to STACP (16.67 ± 1.02%), in fiber STHA (32.66 ± 1.29%) to STHAP (41.58 ± 1.41%) and STAC (29.85 ± 1.6%) to STACP (38.53 ± 1.62%) and in minerals in sauces prepared with potash. The content of other nutrients decreased, especially vitamin C STHA (33.51 ± 0.8%) to STHAP (17.29 ± 1.08%) and STAC (38.53%) to STACP (29.85%), unsaturated STHA (1047.03 ± 0.65%) and STHAP (898.53 ± 4.5%) and STAC (221.76 ± 4.5) to STACP (168.61 ± 0.7%). In addition, all samples had a SAIN score > 5 and a LIM score < 7.5, which is a recommended profile for health. These results showed that « Tchonron » sauce is an important source of nutrients. However, cooking « Tchonron » sauce with potash resulted in more nutrient losses than cooking without potash. An increase in the LIM score of sauces cooked with potash was also observed, so these potash-based sauces should be limited. On the other hand, sauces based on H. asper showed the best nutritional profiles.

A review on soil erosion and its control techniques

This study focuses on Soil erosion, which is a critical environmental challenge, and has profound impacts on agriculture, biodiversity, and water quality. This paper explores the historical and contemporary perspectives of soil erosion in India and globally, highlighting its causes, impacts, and mitigation strategies. India's agrarian economy has long grappled with soil erosion, exacerbated by monsoon-driven climates and unsustainable practices. Traditional conservation methods were undermined during colonial and industrial periods, but modern initiatives like watershed management and soil loss estimation models have renewed focus on combating erosion. At the global level, projects like the GLASOD provide insights into the severity of degradation and the urgency for sustainable practices. In India's arid regions, such as the Thar Desert, wind patterns play a significant role in soil erosion. Seasonal winds cause displacement and nutrient loss, affecting agriculture, infrastructure, and ecosystems. The paper outlines various mitigation strategies, including vegetative barriers, sand fences, chemical stabilizers, and advanced technologies like precision agriculture and geotextiles. Despite progress, challenges persist, such as integrating traditional knowledge with modern techniques and addressing socio-economic barriers. Future directions emphasize holistic approaches, community involvement, and climate-resilient strategies to ensure sustainable soil and ecosystem management.

Deep eutectic solvent-mediated extraction of lignin: A novel strategy for producing high-quality biopolymers in controlled-release mulching applications.

Microplastic contamination of low-density polyethylene mulch and nutrient loss from fertilizers present significant challenges in the crop-growing. In this study, the focus was on creating a biodegradable film that combines the advantages of plastic film, thermal insulation and water retention, as well as the controlled release of fertilizer. A key innovation was the efficient introduction of low molecular weight and low dispersibility of poplar lignin into chitosan and polyvinyl alcohol matrices. The lignin was extracted using deep eutectic solvents of binary carboxylic acids (choline chloride and maleic acid). The refined lignin was used as a superhydrophobic additive to improve the mechanical properties, hydrophobicity, and controlled nutrient release properties of the films through cross-linking. The mulch attained a tensile strength of 37.6 MPa, an elongation of 644.1 %, and a precise release of 53.1 % urea over 30 d at the ideal lignin content ratio (10 %). Furthermore, the film proficiently regulated soil temperature and moisture content. Successful enhancement of cabbage growth was achieved by actual measurements. This discovery provides innovative ideas for the development of nutrient slow-release high-strength integrated agricultural mulching films to promote sustainable, high-quality green agriculture.

Crop Residues: The Unseen Threat to Environmental Sustainability

Crop residue management (CRM) is a critical aspect of sustainable agriculture, addressing significant environmental and economic challenges. In India, the widespread practice of burning crop residues leads to severe air pollution, soil degradation, and health hazards. This paper explores the importance of CRM in environmental conservation, its economic potential, and the sustainable practices available for managing crop residues. It highlights the detrimental effects of residue burning, such as the release of harmful gases (CO2, CH4, NH3), and the subsequent loss of soil nutrients and biomass. The paper also discusses alternative CRM strategies, including composting, mulching, bioenergy production, and biochar utilization, which offer solutions to mitigate environmental damage while improving agricultural productivity and economic returns. The findings underscore the need for integrated approaches involving government policies, technological innovations, and farmer education to promote sustainable CRM practices across India.

The Effects of Potassium Dose, Timing, and Source in Soybean Crops in Brazilian Savannah Oxisol

In Brazil, several silicic rocks can be used as powder-based K sources, which can reduce production costs in agriculture. The optimized supply of K not only increases yield but also contributes to soil fertility preservation and long-term sustainability by curtailing nutrient losses and reducing the risk of nutrient imbalances. Therefore, this study aimed to investigate the effects of K application timing, source, and doses on nodulation, productive components, and productivity of soybeans in a not-tillage system in the Savannah. The experiment was carried out in the field, for two years, in an Oxisol, with a clayey texture. The experimental design was in random blocks, in a 2 × 4 × 3 factorial scheme, as follows: two application timings (early and sowing), four K2O rates (0, 40, 80, and 120 kg ha−1), and three sources (KCl, Potasil, and Ekosil), with four replicates. Potassium fertilizer was broadcasted on the soil without incorporation into the soil. Due to the interactions between doses and K2O sources, there was a linear adjustment for KCl sources, the higher the dose, the lower the nodule mass. Also, for nodule mass, the interaction between dose and application time was significant for the early application of the Ecosil and Potasil sources for 80 kg ha−1. The highest estimated soybean grain productivity was 3262 kg ha−1 with 78 kg ha−1 of K2O, being the most suitable for growing soybeans under a no-tillage system.

Failure to thrive: A proposed diagnostic approach.

Failure to thrive is a general term describing infants who do not reach weight, length, or body mass index expected for their age. It can be related often to malnutrition due to inadequate caloric and protein intake, but also to excessive loss of nutrients, inadequate metabolism, inadequate absorption, or excessive caloric and energy expenditure. It may be either organic or inorganic in origin, and in most cases, does not require investigation through complementary examinations. It is associated with social and health detrimental outcomes. Most cases of failure to thrive are of non-organic etiology, thus clinical history evaluation and physical examination are of utmost importance in the management of these patients. Therapeutics includes behavioral or nutritional interventions, as well as treatment of possible underlying diseases. The treatment approach is more effective in improving clinical outcomes if applied as early as possible.

Effects and function of citric acid on fermentation quality and microbial community in sugarcane tops silage with high and low water-soluble carbohydrate content

Sugarcane tops silage (STS), as a source of roughage for ruminants, is rich in water-soluble carbohydrate (WSC) content, which significantly affects silage quality. Citric acid (CA) is a low-cost natural antimicrobial agent that can inhibit undesirable microbes and improve silage quality. The objectives of this study were to investigate the effects of CA on the chemical composition, fermentation quality, microbial communities, and metabolic pathways of STS with high and low WSC contents before or after aerobic exposure. Fresh sugarcane tops with low-WSC [143.05 g/kg dry matter (DM)] and high-WSC (249.99 g/kg DM) contents were treated with and without CA and then ensiled for 125 days, followed by aerobic exposure for 4, 8, and 16 days. The results showed that high-WSC STS had lower crude protein (CP) content and higher DM, neutral detergent fiber (NDF), and acid detergent fiber (ADF) contents, whether treated with CA or not. CA-inoculated silage exhibited decreased DM loss and enterobacteria (EB) counts compared to the control. High-WSC STS treated with CA had higher WSC content and lower yeast count than those without CA inoculation. During the 0–16 days of aerobic exposure, the propionic acid and butyric acid contents in CA-inoculated silage were almost unchanged and ranged from 0 to 1 g/kg DM. Meanwhile, the ethanol content was almost unchanged and ranged from 0 to 1 g/kg DM only in low-WSC STS, irrespective of CA addition. Before aerobic exposure, CA inoculation decreased the abundances of undesirable microbes (e.g., Clostridium_sensu_stricto_12 and Paecilomyces) and animal pathogens, while amino acid metabolism was lower in high-WSC STS regardless of CA treatment. After aerobic exposure, CA inoculation increased the abundance of bacteria with antibacterial effects, including Paenibacillus and Bacillus. Moreover, the metabolism of energy and nucleotides was lower in high-WSC STS treated with CA, and the animal pathogens was lower in low-WSC STS treated with CA. In conclusion, CA inoculation could be effective in decreasing nutrients loss, improving fermentation quality, inhibiting harmful microorganisms, and modulating the metabolic pathways of microorganisms in STS with high and low WSC contents prior to and after aerobic exposure.

Quantitative and qualitative food losses of African indigenous vegetables along the value chain: A systematic literature review

African indigenous vegetables (AIV) have high densities of important micronutrients but qualitative and quantitative food losses along the value chains could threaten their nutritional potential in Africa. We conduct a systematic review of the estimations of food quality losses of AIV along their value chains. Our review reveals that there is generally limited evidence on food quality losses along AIV value chains. In addition, existing studies are often of low quality and have inadequate experimental descriptions. For our final analysis, we consider the yields and malnutrition-relevant nutrients for two major AIV, vegetable amaranth ( Amaranthus ssp) and African nightshade ( Solanum nigrum and Solanum scarbrum). We observe a consistent and substantial decrease in carotenoids and iron contents starting from selecting appropriate seed material to processing practices. Losses are particularly severe at seed selection and production. Almost half of the original potential is lost after cultivation for the reviewed nutrients. While qualitative losses appear to be significant during post-harvest, processing by consumers leads to comparatively small reductions. While our results suggest that the current value chains need to be improved to supply nutrient-rich foods to urban and peri-urban areas, better data are also needed to conduct more comprehensive assessments of nutrition-sensitive AIV value chains and to derive evidence-based interventions to reduce nutrient losses for AIV along the value chain.

Effect of Nutrient Management on Ricebean [Vigna umbellata (Thunb.) Ohwi and Ohashi]- linseed (Linum usitatissimum L.)

Background: Soil fertility depletion is a major constraint on agricultural production, necessitating a balanced application of inorganic and organic nutrients while effective crop residue management post-harvest enhances soil quality and structure, mitigates evaporation and aids carbon fixation. In Nagaland, agriculture faces challenges like nutrient loss from erosion and minimal use of external inputs while sustainable agriculture requires a viable cropping system and effective crop management; technological advancements in agro-techniques, particularly in cropping systems and nutrient management, are crucial for improving productivity in a ricebean-based linseed cropping system. Methods: A field experiment was conducted to focus on green manuring followed by cultivating a legume crop, rice bean and subsequently linseed in 2019-2021, the investigation would carry out to study the growth, yield and quality parameter and the study was laid in randomized block design with three replications and nine treatments with sources of organic manures and inorganic fertilizers. Result: The study revealed substantial influence of growth and yield which included a combination of poultry manure at 0.7 tons ha-1 along with 100% RDF exhibited superior performance in ricebean, a similar trend was also observed in the subsequent crop, which was linseed and also yielded promising results in terms of plant height, nodules, pods plant-1, seeds pods-1 and yield and concluded to achieve higher seed yield, improve seed quality, preserve soil quality.

Unraveling the nutritional potential of millet by-products through extraction of high value compounds for the development of novel food products.

Millets are drought-resistant crops that generate significant amount of by-products (bran, husk, stalk etc.) during harvesting and processing. These by-products are storehouse of nutrients and high value compounds including polyphenols, dietary fiber, proteins etc. However, these by-products remain underutilized and generally discarded, burned or used as feedstock causing adverse impact on the environment and human health in addition to loss of valuable nutrients. Therefore, the valorization of millet by-products offers sustainable approach to enhance food product innovation while reducing agricultural waste. Green extraction techniques can be employed to recover antioxidants, phenolics, and bioactive peptides from these by-products. The incorporation of these ingredients into food products can significantly improve the nutritional profile, functional characteristics, like antioxidant, prebiotic, anti-diabetic, and anticarcinogenic properties. The review highlights the feasibility of upcycling millet by-products into high-value components, which can address the growing demand for health-oriented food products contributing towards food security, sustainability and circular economy.

Sustainable Intensification and Climate Resilience in the Rice-wheat Cropping System of North-Western India: Challenges and Strategies

In northwestern India, the rice-wheat cropping system (RWCS) is a key component of agriculture. However, the region's ongoing usage of it has resulted in serious problems and a halt in productivity. Similar problems are also present in Bangladesh, Nepal, and Pakistan's Indo-Gangetic Plains. Key issues include the loss of soil nutrients, deteriorating soil health, groundwater depletion, increased production costs, a lack of workers, pollution from burning crop residue, increased greenhouse gas emissions, climate vulnerabilities, and plants that are resistant to herbicides. To address these issues, a number of sustainable intensification methods have been proposed, such as crop diversification, zero tillage, or residue retention, which reduce tillage, handle straw more efficiently, and use less labour and irrigation. In order to adopt successful, context-specific tactics, it is necessary to concentrate on increasing awareness, developing stakeholder capacity, and coordinating policies. The current status of the RWCS and its problems in northwest India are summarised in this report, along with specific management strategies for boosting output, profitability, and sustainability.

Effect of Pre-Emulsified Flaxseed Oil Containing Rutin on the Quality of Nemipterus virgatus Surimi Gel: Gelatinization Properties, Storage Stability, and Protein Digestibility.

Rinsing during surimi protein processing can result in the loss of essential nutrients, such as fats and minerals. Therefore, supplementing functional fats in a stable form can make up for the fat loss of surimi during the rinsing process. This research aimed to investigate the effects of incorporating pre-emulsified flaxseed oil with different concentrations of rutin (0, 0.5, 1.5, 2.5, and 3.5%, dissolved in flaxseed oil, w/v) to Nemipterus virgatus surimi on the gelatinization properties, lipid oxidation, and in vitro static simulated digestion characteristics of surimi gels. The results indicated that the addition of 1.5% rutin significantly improved the water-holding capacity and decreased the cooking loss rate of surimi gel (p < 0.05). The results of optical microscopy and scanning electron microscopy showed that the addition of 1.5% rutin promoted a denser network structure of surimi gel. Furthermore, the incorporation of rutin effectively slowed lipid oxidation in pre-emulsified flaxseed oil surimi gel. Compared with the gel group containing only pre-emulsified flaxseed oil, the addition of rutin significantly reduced the levels of volatile base nitrogen (TVB-N) and thiobarbituric acid reactive substances (TBARSs) in the gel and also mitigated the decline in acidity (p < 0.05). Moreover, the addition of rutin significantly inhibited the decrease in pH of surimi gel during storage (p < 0.05). In vitro static simulated digestion demonstrated that the addition of 1.5% rutin enhanced the protein digestibility from 71.2% to 77.2% of the surimi gel. Therefore, adding pre-emulsified oil containing an appropriate amount of rutin to surimi can not only compensate for the fat loss during the surimi rinsing process but also effectively improve the quality characteristics of surimi gels. This research will provide a theoretical basis for the effective addition of functional lipids in surimi products and the development of nutritious and healthy surimi products.

Evaluating the Nutritive Value and Quality of Fodder Pea (Pisum arvense L.) Silage Added with Varying Rates of Barley (Hordeum vulgare L.) and Wheat (Triticum aestivum L. Em Thell) Cracks

Silage represents the most effective solution for addressing the deficit in quality, abundance and cost-effectiveness of roughage. The main purpose of silage production is to store fresh herbage material with high nutritional value with minimum nutrient loss. For fodder and silage production, fodder pea is grown in mixtures with cereals in different ratios, but also for the silage from the pure fodder pea using additives. Molasses and crashed cereal grains or cereal can be added to silage material in order to increase its carbohydrate content. The research was conducted to determine nutritive value and silage quality of barley and wheat cracks added at different ratios to fodder pea silage in complete randomized split-plot design with four replications. 100 g withered fodder pea sample without additives and 100 g withered fodder pea sample with 3 g, 6 g, 9 g and 12 g cracked barley were vacuumed in to the 20x26 cm plastic bags and were stored in a dark environment for a period of 45 days to facilitate fermentation at ambient temperatures ranging from 15 to 28°C. Crude protein (%), crude ash (%), dry matter (%), digestible dry matter (DDM, %), dry matter intake (DMI, %), ADF (%), NDF (%), P (%), K (%), Ca (%), Mg (%), total digestible nutrients (TDN), Nel, NEm, Neg, pH, Fleig Score and RFV of pure fodder pea and cracked barley and wheat added silages were determined. According to results, fodder peas, which have a high protein and low carbohydrate content, be ensiled by the addition of high-carbohydrate wheat and barley cracks in order to obtain a quality silage. For this purpose, it is suggested to add at least 6% wheat cracks or 9% barley cracks to fodder pea silage.

Trends of Soil and Solution Nutrient Sensing for Open Field and Hydroponic Cultivation in Facilitated Smart Agriculture.

Efficient management of soil nutrients is essential for optimizing crop production, ensuring sustainable agricultural practices, and addressing the challenges posed by population growth and environmental degradation. Smart agriculture, using advanced technologies, plays an important role in achieving these goals by enabling real-time monitoring and precision management of nutrients. In open-field soil cultivation, spatial variability in soil properties demands site-specific nutrient management and integration with variable-rate technology (VRT) to optimize fertilizer application, reduce nutrient losses, and enhance crop yields. Hydroponic solution cultivation, on the other hand, requires precise monitoring and control of nutrient solutions to maintain optimal conditions for plant growth, ensuring efficient use of water and fertilizers. This review aims to explore recent trends in soil and solution nutrient sensing technologies for open-field soil and facilitated hydroponic cultivation, highlighting advancements that promote efficiency and sustainability. Key technologies include electrochemical and optical sensors, Internet of Things (IoT)-enabled monitoring, and the integration of machine learning (ML) and artificial intelligence (AI) for predictive modeling. Blockchain technology is also emerging as a tool to enhance transparency and traceability in nutrient management, promoting compliance with environmental standards and sustainable practices. In open-field soil cultivation, real-time sensing technologies support targeted nutrient application by accounting for spatial variability, minimizing environmental risks such as runoff and eutrophication. In hydroponic solution cultivation, precise solution sensing ensures nutrient balance, optimizing plant health and productivity. By advancing these technologies, smart agriculture can achieve sustainable crop production, improved resource efficiency, and environmental protection, fostering a resilient food system.

Analysis of the Factors Influencing the Calories of Cereals

Cereals are a major global source, classified into whole and refined grains. Whole grain cereals provide a higher nutritional value due to the inclusion of the bran, germ, and endosperm, making them a rich source of dietary fiber, vitamins, and minerals. Conversely, refined grains undergo processing that eliminates the bran and germ components, resulting in a loss of valuable nutrients. In recent years, there has been a growing interest in exploring the health benefits of whole grain cereals. Research has established a connection between whole grains consumption and reduced risks of chronic diseases such as heart disease, diabetes, and certain cancers. Additionally, whole grains are recognized for their role in maintaining digestive health and promoting satiety which can aid in weight management. Therefore, this paper aims to investigate how various element present total calorie content using R-studio. The findings reveal that calories serves as the independent variable while protein content, type, sugars and carbohydrates act as independent variables influencing calorie levels accordingly. Cereal type plays a negative role by increasing calories whereas other factors contribute positively positively towards increased caloric intake levels

Increasing pesticide diversity impairs soil microbial functions

Pesticide application is essential for stabilizing agricultural production. However, the effects of increasing pesticide diversity on soil microbial functions remain unclear, particularly under varying nitrogen (N) fertilizer management practices. In this study, we investigated the stochasticity of soil microbes and multitrophic networks through amplicon sequencing, assessed soil community functions related to carbon (C), N, phosphorus (P), and sulfur (S) cycling, and characterized the dominant bacterial life history strategies via metagenomics along a gradient of increasing pesticide diversity under two N addition levels. Our findings show that higher pesticide diversity enriches the abundance of bacterial specialists and opportunists capable of degrading or resisting pesticides, reducing the proportion of bacterial generalists in the absence of N addition. These shifts can complicate multitrophic microbial networks. Under increased pesticide diversity, selective pressure may drive bacteria to streamline their average genome size to conserve energy while enhancing C, N, P, and S metabolic capacities, thus accelerating soil nutrient loss. In comparison, N addition was found to reduce bacterial niche differentiation at higher pesticide diversity, mitigating the impacts of network complexity and functional traits associated with pesticide diversity, ultimately alleviating soil nutrient loss. Our results reveal the contrasting impacts of pesticide diversity on microbial functions under different N input scenarios and emphasize that strategic N fertilizer management can mitigate the ecological effects of pesticide use in agricultural systems.

Understanding and managing nutrient pollution in peri-urban wetlands: The Ciénegas del Lerma, Mexico.

Nutrient pollution has been broadly studied in developed countries, where the primary source is often agricultural diffuse pollution. However, more research is needed in developing countries with a predominance of low-income households, insufficient public service infrastructure, pressure from urban expansion, and scarce information. In this research, centered on the Lerma Cienega protected wetlands in a peri-urban area of Toluca city in Mexico, a socio-ecological systems framework was applied to study the nutrient pollution problem and recommend nutrient control measures. An export coefficient model was developed to estimate nutrient losses from micro-basin areas discharging to the wetlands, which range from 0 to 32 tonnes/year for nitrogen (N) and 0-4.6 tonnes/year for phosphorus (P). The highest annual N loss occurs in the case of a combination of agriculture or grassland with slow infiltration soils. In contrast, P loss is associated with agriculture or urban land use in combination with slow infiltration soils. By determining the sources and estimating the magnitude of nutrient pollution, nutrient mitigation solutions were considered for the peri-urban wetlands where low-income communities surround the immediate area and connections with urban and local communities facilitate options to conserve natural assets. In conclusion, controlling nutrient pollution can improve the protection of natural aquatic resources and the living conditions of local communities while generating other benefits for surrounding urban areas.

Subsurface hydrological controls on the short-term effects of hurricanes on nitrate–nitrogen runoff loading: a case study of Hurricane Ida using the Energy Exascale Earth System Model (E3SM) Land Model (v2.1)

Abstract. When the nutrient level in the soil surpasses vegetation demand, nutrient losses due to surface runoff and subsurface leaching are the major reasons for the deterioration of water quality. The lower Mississippi River basin (LMRB) is one of the sub-basins that deliver the highest nitrogen loads to the Gulf of Mexico. Potential changes in episodic events induced by hurricanes may exacerbate water quality issue in the future. However, uncertainties in modeling the hydrologic response to hurricanes may limit the modeling of nutrient losses during such events. Using a machine learning approach, we calibrated the land component of the Energy Exascale Earth System Model (E3SM), or ELM, version 2.1, based on the water table depth (WTD) of a calibrated 3D subsurface hydrology model. While the overall performance of the calibrated ELM is satisfactory, some discrepancies in WTD remain in slope areas with low precipitation due to the missing lateral flow process in ELM. Simulations including biogeochemistry performed using ELM with and without model calibration showed important influences of soil hydrology, precipitation intensity, and runoff parameterization on the magnitude of nitrogen runoff loss and the leaching pathway. Despite such sensitivities, both ELM simulations produced reduced WTD and increased runoff and accelerated nitrate–nitrogen runoff loading during Hurricane Ida in August 2021, consistent with the observations. With observations suggesting more pronounced effects of Hurricane Ida on nitrogen runoff than the simulations, we identified factors for model improvement to provide a useful tool for studying hurricane-induced nutrient losses in the LMRB region.