Nutrient Transport Processes Research Articles

Unraveling the declining Indian ocean primary productivity and key drivers

Climate change severely affects the third-largest maritime regions, disrupting physical and biogeochemical processes and Ocean Net Primary Productivity (NPP), which affects the marine food web, fisheries, and livelihoods of surrounding regions. This study examined changes in NPP in the Indian Ocean and its drivers. The Ocean warming, equatorial and Pacific warm pools, stratification fluctuations, circulation changes, nutrient transport, monsoons, and different seasonal processes significantly influenced these microbial mats. The Copernicus Marine Environment Monitoring Service (CMEMS) reanalysis data shows a high declining NPP trend in the Indian Ocean (-0.85 mgC/m3/day/yr). The high warming rate (0.01–0.02 °C/yr) primarily drives regional NPP alterations. The causal discovery analysis shows that sea surface temperature (SST) provides high negative feedback to NPP during all-time delays. Nitrate and phosphate show a positive association, reinforcing positive feedback, and Redfield stoichiometry holds paramount significance in fostering the NPP. Negative feedback is observed from the Western Pacific Index (WP), Oceanic Niño Index (ONI), Multivariate ENSO Index (MEI), and Pacific Decadal Oscillation (PDO). This climate pattern can modify mesoscale atmospheric circulation, influence currents, and change temperature and nutrient availability. The positive connection between the Southern Oscillation Index (SOI) and NPP underscores the complex interplay between climate patterns in the region. The Indian Ocean Dipole (IOD) negatively feedbacks the NPP. Various other climate patterns and events indirectly affect IO biogeochemical processes.

A new understanding of the regulatory mechanism by which Fe/Mn nanoparticles boost Bisphenol A removal using Comamonas testosteroni

Green synthesized iron/manganese nanoparticles (Fe/Mn NPs), acted as an exogenous promoter to enhance the lignin-degrading bacteria Comamonas testosteroni FJ17 resulting in more efficient removal of bisphenol A (BPA). Batch experiments demonstrated that removal efficiency of BPA via cells at a BPA concentration of 10 mg·L−1 increased by 20.9 % when exposed to 100 mg·L−1 Fe/Mn NPs after 48 h (93.63 %) relative to an unexposed control group (72.70 %). TEM and 3D-EEM analysis confirmed that the cell membrane thickness increased from 47 to 80 nm under Fe/Mn NPs exposure, and the TB-EPS secretion was promoted. Meanwhile, Fe/Mn NPs facilitated greater electron transfer capacity of c-cytochrome (0.55 V reduction peak) and an unknown cytochrome substance (0.7 V oxidation peak) on the surface of cells. Studies of the effect of Fe/Mn NPs on both the growth and activity of laccase cells showed that both biomass and laccase secretion increased significantly during the logarithmic growth period (6–36 h). LC-MS analysis and toxicity assessment indicated that Fe/Mn NPs decreased the degradation time of BPA and efficiently reduced the toxicity of its by-products. Transcriptomic analysis revealed 315 up-regulation of the key genes associated with energy supply, membrane translocation, and metabolic pathways upon exposure to Fe/Mn NPs. Such as MFS transporter (2.27-fold), diguanylate cyclase (1.76-fold) and protocatechuate-3,4-dioxygenase (1.62-fold). Overall, Fe/Mn NPs accelerated proliferation by enhancing metabolic capacity and nutrient transport processes, which serves to improve the efficiency of BPA removal.

Nutrients transport behavior in inlet river in the Yellow River Delta in winter

The nutrients such as dissolved inorganic nitrogen (DIN, NH4+-N, NO2−-N, and NO3−-N), dissolved inorganic phosphorus (DIP, PO43−) and dissolved SiO2 (DSi) funneled by the inlet river are the dominant factors to coastal eutrophication. This study investigated nutrient transport process in typical inlet rivers in the Yellow River Delta. The indicator of coastal eutrophication potential and concentration ratio between upstream and downstream stations were used to evaluate the influence of different sources to the nutrient risks. It showed that urban areas are the most important source of the nutrients in studied rivers. The harbor and mariculture would have greater risk because of their proximity close to the coastal area. Wetland was a vital conversion to eliminate the river nutrients, and the retention could reach 80 %. It is imperative to protect and construct wetlands to reduce the nutrient pollution in the inlet river.

Cadmium accumulation in brown rice (Oryza sativa L.) depends on environmental factors and nutrient transport: A three-year field study

Cadmium (Cd) accumulation in brown rice is a complex process in agroecosystems and is influenced by multiple factors, such as climate, soil properties, and nutrient transport. However, during the Cd transport process (soil-root-straw-brown rice), it remains unclear how Cd concentration in brown rice (BCd) is causal relationship to environmental factors and nutrient transport. The differences in precipitation, soil properties, nutrient transport, and Cd transport were studied through a three-year fixed-point field trial and linked them to the standard of Cd and nutrient absorption and transport processes. The results showed that the available Cd concentration (ACd), and BCd in 2020 were lower than those in 2019 and 2021, but monthly precipitation (MP) was higher in 2020 than in 2019 and 2021. The MP and niche metrics were significantly negatively associated with ACd and BCd. However, the relationship between the form and location of different nutrient elements and Cd in roots, Cd in straws, and BCd also varied during the transport of nutrient elements and Cd from soil to root to straw to brown rice. Structural equation modelling analysis showed that nitrogen (N 15.5 %), phosphorus (P 14.1 %), silicon (Si 4.2 %), and iron (Fe 7.6 %) transport were more closely related to BCd than to potassium (K), calcium (Ca), magnesium (Mg), and manganese (Mn). The increase in MP significantly inhibited the increase in BCd, whereas the MP led to a decrease in BCd by affecting the transport of N and Fe. Among them, Si, Fe, and BCd had indirect causal relationships, whereas N, P, and BCd had direct causal relationships. Particularly, P is a crucial nutrient in reducing BCd in the Cd transport process. Our results highlight a strong causal relationship between environmental factors and nutrient transport and BCd, and provide a theoretical basis for fertiliser application in Cd-contaminated agroecosystems.

Proposed Business Strategy for New Healthcare Innovation of Electro-Capacitive Body Stimulation (ECBS) Technology

One of the greatest healthcare challenges in Indonesia is providing an adequate environment and healthcare infrastructure that ensures that people obtain the best treatment that conforms to their expectations, preferences, and needs. Therefore, healthcare technology players have a crucial role in overcoming this challenge and creating a better solution to the system. Electro Capacitive Body Stimulation (ECBS) is a technology that utilizes electric pulses to stimulate the body’s muscles and organs to optimize waste removal and nutrient transport process. As a result, the body will be conducive to physical well-being. For the elderly, who start to experience slowing down in physical ability and degeneration of organ functions, this technology is beneficial to maintain their health condition and prevent future chronic disease. However, the market performance is not live up to the fineness of this technology, even with all its benefits and technological advancement. As a matter of fact, sales have been disappointing by the year since the product is launched to the public. A number of factors contributed to this unsatisfactory sale encompassing internal and external conditions of the company. Through the analysis of internal and external environments as well as primary and secondary data, research is conducted to identify the contributing factors to the unsatisfactory sales and potential value of the technology. Based on the analysis and findings, a SWOT analysis that defines the unsatisfactory business performance factors and potential technology value and the TOWS matrix that bases the business strategy can be described. It includes the diamond model, STP and 7PS marketing, and business model canvas as the proposed solution for the business.

A new framework to model the distributed transfer and retention of nutrients by incorporating topology structure of small water bodies

Small water bodies such as interval water-flooded ditches, ponds, and streams serve as important nutrient sinks in many landscapes, especially in the multi-water continuum system. Yet watershed nutrient cycling models often fail to or insufficiently capture these waters, resulting in great uncertainty in quantifying the distributed transfer and retention of nutrients across diverse landscapes in a watershed. In this study, we present a network-based predictive framework of the nutrient transport process in nested small water bodies, which incorporates topology structure, hydrological and biogeochemical processes, and connectivity to perform a nonlinear and distributed scaling of nutrient transfer and retention. The framework was validated and applied to N transport in a multi-water continuum watershed in the Yangtze River basin. We show that the importance of N loading and retention depends on the spatial context of grid source and water bodies because of the great variation in location, connectivity, and water types. Our results demonstrate that hotspots in nutrient loading and retention could be accurately and efficiently identified through hierarchical network effects and spatial interactions. This offers an effective approach for the reduction of watershed-scale nutrient loads. This framework can be used in modeling to identify where and how to restore small water bodies for reduced non-point pollution from agricultural watersheds.

A method for quantitation of apoplast hydration in Arabidopsis leaves reveals water-soaking activity of effectors of Pseudomonas syringae during biotrophy

The plant apoplast has a crucial role in photosynthesis and respiration due to its vital function in gas exchange and transpiration. The apoplast is also a dynamic environment that participates in many ion and nutrient transport processes via plasma membrane-localized proteins. Furthermore, diverse microbes colonize the plant apoplast, including the hemibiotrophic bacterial pathogen, Pseudomonas syringae pv. tomato (Pto) strain DC3000. Pto DC3000 initiates pathogenesis upon moving through stomata into the apoplast and then proliferating to high levels. Here we developed a centrifugation-based method to isolate and quantify the apoplast fluid in Arabidopsis leaves, without significantly damaging the tissue. We applied the simple apoplast extraction method to demonstrate that the Pto DC3000 type III bacterial effectors AvrE1 and HopM1 induce hydration of the Arabidopsis apoplast in advance of macroscopic water-soaking, disruption of host cell integrity, and disease progression. Finally, we demonstrate the utility of the apoplast extraction method for isolation of bacteria proliferating in the apoplast.

Integrating source apportionment and landscape patterns to capture nutrient variability across a typical urbanized watershed

Effective integrated watershed management requires models that can characterize the sources and transport processes of pollutants at the watershed with multiple landscape patterns. However, few studies have investigated the influence of landscape spatial configuration on pollutant transport processes. In this study, the SPARROW_TN and SPARROW_TP models were constructed by combining direct pollution source data and landscape pattern data to investigate the source composition and nutrient transport processes and to reveal the influence of landscape patterns on nutrient transport in the urbanized Beiyun River Watershed. The introduction of landscape metrics significantly improved the simulation results of both models, with R2 increasing from 0.89 to 0.85 to 0.93 and 0.91, respectively. Spatial variations existed in TN and TP loads and yields, as well as the source compositions. Pollution hotspots were effectively identified. Source apportionment showed that for the entire watershed, TN came from atmospheric nitrogen deposition (35.25%), untreated sewage (28.23%), agricultural sources (22.60%), and treated sewage (13.92%). In comparison, TP came from untreated sewage (44.94%), agricultural sources (40.22%), and treated sewage (11.51%). In addition, the largest patch index of grassland correlated positively with both TN and TP, whereas the largest shape index of buildup land and interspersion and juxtaposition index of forest were negatively correlated with TN and TP, respectively. The results of this study will provide insight into effective nutrient control measures that consider spatially varying nutrient sources and associated nutrient transport processes.

The Ton Motor.

The Ton complex is a molecular motor at the inner membrane of Gram-negative bacteria that uses a proton gradient to apply forces on outer membrane (OM) proteins to permit active transport of nutrients into the periplasmic space. Recently, the structure of the ExbB–ExbD subcomplex was determined in several bacterial species, but the complete structure and stoichiometry of TonB have yet to be determined. The C-terminal end of TonB is known to cross the periplasm and interact with TonB-dependent outer membrane transport proteins with high affinity. Yet despite having significant knowledge of these transport proteins, it is not clear how the Ton motor opens a pathway across the outer membrane for nutrient import. Additionally, the mechanism by which energy is harnessed from the inner membrane subcomplex and transduced to the outer membrane via TonB is not well understood. In this review, we will discuss the gaps in the knowledge about the complete structure of the Ton motor complex and the relationship between ion flow used to generate mechanical work at the outer membrane and the nutrient transport process.

Changes in porcine nutrient transport physiology in response to Ascaris suum infection

BackgroundThe roundworm Ascaris suum is one of the parasites with the greatest economic impact on pig farming. In this context, lower weight gain is hypothesized to be due to decreased nutrient absorption. This study aims at characterizing the effects of A. suum infection on intestinal nutrient transport processes and potential molecular mechanisms.MethodsThree groups of six piglets each were infected orally (10,000 embryonated A. suum eggs) in a single dose (“single infection”). Another three groups were infected orally (1000 embryonated eggs) for 10 consecutive days (“trickle infection”). Animals were necropsied 21, 35 and 49 days post-infection (dpi). Three groups served as respective controls. The Ussing chamber technique was applied for the functional characterization of small intestinal tissues [short-circuit currents (Isc) as induced by glucose, alanine and peptides; 3H-glucose net flux rates; tissue conductance (Gt)]. Transcription and expression levels of relevant cytokines and nutrient transporters were evaluated (qPCR/western blot).ResultsPeptide- and alanine-induced changes in Isc were significantly decreased in the jejunum and ileum of the trickle-infected group at 49 dpi and in the ileum of the single-infected group at 49 dpi. No significant differences regarding glucose transport were observed between the Ascaris-infected groups and the control group in Ussing chamber experiments. Transcription levels of the glucose and peptide transporters as well as of selected transcription factors (transcription of signal transducer and activator of transcription 6 [STAT6] and hypoxia-inducible factor 1-alpha [Hif-1α]) were significantly increased in response to both infection types after some periods. The transcription of interleukins 4 and 13 varied between decrease and increase regarding the respective time points, as did the protein expression of glucose transporters. The expression of the peptide transporter PepT1 was significantly decreased in the ileal single-infected group at 35 dpi. Hif-1α was significantly increased in the ileal tissue from the single-infected group at 21 dpi and in the trickle-infected group at 35 dpi. The expression levels of Na+/K+-ATPase and ASCT1 remained unaffected.ConclusionsIn contrast to the current hypothesis, these results indicate that the nutrient deprivation induced by A. suum cannot be explained by transcriptional or expression changes alone and requires further studies.Graphical abstract

Modelled estimates of fine sediment and particulate nutrients delivered from the Great Barrier Reef catchments

The eWater Source modelling framework has been modified to support the Great Barrier Reef (GBR) Dynamic SedNet catchment modelling concept, which is used to simulate fine sediment and particulate nutrient generation, loss, and transport processes across GBR catchments. Catchment scale monitored data sets are used to calibrate and evaluate models. Model performance is assessed qualitatively and quantitatively. Modelling predicts that approximately half of generated sediment is delivered to the GBR lagoon; the remainder is deposited on floodplains, trapped in reservoirs or lost through other minor processes (e.g. irrigation extractions). Gullies are the major source of sediment, with comparable contributions from hillslopes and streambanks. Hillslope sources are considered the major source of particulate nutrients across the GBR catchments. We demonstrate that using locally developed, customised models coupled with a complementary monitoring program can produce credible modelled estimates of pollutant loads and provide a platform for testing catchment scale assumptions and scenarios.

Does resin tapping affect the tree-ring growth and climate sensitivity of the Chinese pine (Pinus tabuliformis) in the Loess Plateau, China?

Resin tapping could affect water and nutrient transport processes in Chinese pine trees, rendering them more vulnerable to extreme climatic events, such as drought, and affecting the ecological function of forests in semi-arid regions. This study evaluated how resin tapping affects the tree-ring growth and climate sensitivity of Chinese pine in the Loess Plateau. We compared tree-ring growth patterns between the tapped and untapped faces of tapped trees, and investigated tree-ring growth and its response to climate between tapped and untapped trees in a forest stand during the 1967–2017 period. Tapped trees showed asymmetrical growth patterns after resin tapping, with narrower rings near the tapped face and wider ones near the untapped face. Furthermore, tapped trees had inter-annual variations consistent with those of untapped trees except for the years 2000 and 2001, with significantly lower values following resin tapping, and tree-ring growth then returning to normal. The climate response analysis indicated that the tree-ring growth of both tapped and untapped trees was negatively affected by monthly mean temperatures during the early growing season (May to July) in the post-resin-tapping period. Furthermore, tree-ring growth in tapped trees also revealed significant correlation with water vapour deficit and the Palmer drought index, which indicates that tapped trees are more vulnerable to drought. Further studies based on stable isotopes (i.e. δ13C, δ18O, and δ15N) could improve our understanding of the physiological mechanisms that regulate the effects of resin tapping on tree-ring growth.

Evaluating the dynamics of groundwater, lakebed transport, nutrient inflow and algal blooms in Upper Klamath Lake, Oregon, USA

Transport of nutrients to lakes can occur via surface-water inflow, atmospheric deposition, groundwater (GW) inflow and benthic processes. Identifying and quantifying within-lake nutrient sources and recycling processes is challenging. Prior studies in hypereutrophic Upper Klamath Lake, Oregon, USA, indicated that ~60% of the early summer phosphorus (P) load to the lake was internal and hypothesized to be lakebed sediment release. Dynamic nutrient transport processes were examined to better characterize the nutrient sources. One-dimensional heat transport models calibrated to observed lakebed temperatures and a cross-sectional GW flow model provided estimates of GW-inflow rates that were greatest in spring and decreased through summer. One-dimensional solute transport models calibrated to observed lakebed pore-water dissolved silica (Si) and dissolved phosphate-phosphorus (DP) concentrations indicated that nutrients were transported from the lakebed by advection, diffusion, and enhanced mixing by benthic organisms and waves, and that DP removal occurred near the lakebed interface. Estimated water, Si, DP and total-phosphorus (TP) budgets indicated that GW contributed 21% of lake water inflow and at least 26, 20 and 16% of total Si, DP and TP inflow, respectively, when conservatively assuming background GW nutrient concentrations. However, lakebed GW (LGW) is enriched in nutrients during flow through lakebed sediment and the estimated GW contribution increased to 29 (33), 49 (67) and 43% (61%) of total Si, DP and TP inflow, respectively, if 20% (50%) of GW inflow to the lake was assumed to have LGW concentrations. Net nutrient inflow to the lake was greatest in spring and coincident with the annual diatom bloom. Inflowing dissolved nutrients appear to be assimilated by diatoms during the spring and become available for the summer Aphanizomenon flos-aquae bloom when the diatoms senesce. Thus, nutrient-enriched GW inflow and nutrient recycling by successive algal blooms must be considered when evaluating internal nutrient loading to lakes.

On modelling of glucose transport in hollow fibre membrane bioreactor for growing three‐dimensional tissue

AbstractHollow fibre membrane bioreactors (HFMBs) have been shown to overcome the diffusion limitation of nutrients (e.g., glucose) from the hollow fibres (lumens) to the porous regions of a scaffold (extracapillary space). However, direct monitoring of glucose diffusion inside the HFMBs is almost impossible because of their small size; thus, various computational modelling frameworks have been developed in the past. These models have defined that the glucose diffusivity in the cell culture medium used in the HFMBs was similar to the diffusivity in water. Similarly, other assumptions have been made that do not represent the nutrient transport processes in the HFMB accurately. In addressing these issues, a mathematical model is presented in this paper, where we employ experimentally deduced effective glucose diffusivities of tissue engineering membranes and scaffolds with and without cells along with glucose diffusivity in cell culture medium. The governing equations are non‐dimensionalized, simplified and solved numerically. The results demonstrate the roles of various dimensionless numbers (e.g., Péclet and Damköhler numbers) and non‐dimensional groups of variables on determining the glucose concentration especially in the scaffold region. The result of this study is expected to help optimize designs of HFMB as well as carry out more accurate scaling analyses.

Pore-scale lattice Boltzmann modeling of solute transport in saturated biochar amended soil aggregates

Biochar has been increasingly used as an amendment to enhance soil structure and improve soil hydraulic properties. Nevertheless, there are very limited physically based studies to investigate solute transport in biochar-amended soils at pore scale. In this study, for the first time, synchrotron-based X-ray micro-computed tomography (SR-μCT) was used to obtain high-resolution pore geometries of two clayey soils and their biochar amended samples, then the three-dimensional lattice Boltzmann (LB) method was implemented to simulate solute transport using the pore structure information. By using the innovative method of combining SR-μCT and LB simulation, we found that biochar amendment reduced the spatial variability of pore water velocity and increased the dispersion coefficient by one order of magnitude. In addition, we observed that anomalous dispersion was more likely to occur in soils with biochar amendment. Furthermore, soils after biochar amendment had relatively higher thresholds of both the transition zone and advection-dominated zone for the dispersion coefficients. These results are crucial in understanding nutrient transport processes and contaminant migration occurring at pore scale.

Agricultural Water Quality in Cold Environments

Agricultural Water Quality in Cold Environments

Agricultural Water Quality in Cold Climates: Processes, Drivers, Management Options, and Research Needs.

Cold agricultural regions are important sites of global food production. This has contributed to widespread water quality degradation influenced by processes and hydrologic pathways that differ from warm region analogues. In cold regions, snowmelt is often a dominant period of nutrient loss. Freeze-thaw processes contribute to nutrient mobilization. Frozen ground can limit infiltration and interaction with soils, and minimal nutrient uptake during the nongrowing season may govern nutrient export from agricultural catchments. This paper reviews agronomic, biogeochemical, and hydrological characteristics of cold agricultural regions and synthesizes findings of 23 studies that are published in this special section, which provide new insights into nutrient cycling and hydrochemical processes, model developments, and the efficacy of different potentially beneficial management practices (BMPs) across varied cold regions. Growing evidence suggests the need to redefine optimum soil phosphorus levels and input regimes in cold regions to allow achievement of water quality targets while still supporting strong agricultural productivity. Practices should be considered through a regional and site-specific lens, due to potential interactions between climate, hydrology, vegetation, and soils, which influence the efficacy of nutrient, crop, water, and riparian buffer management. This leads to differing suitability of BMPs across varied cold agricultural regions. We propose a systematic approach (""), to achieve water quality objectives in variable and changing climates, which combines nutrient transport process onceptualization, nderstanding BMP functions, redicting effects of variability and change, onsideration of producer input and agronomic and environmental tradeoffs, practice daptation, nowledge mobilization, and valuation of water quality improvement.

A Mathematical Model of Corneal Metabolism in the Presence of an Iris-Fixated Phakic Intraocular Lens

Corneal endothelial cell loss is one of the possible complications associated with phakic iris-fixated intraocular lens (PIOL) implantation. We postulate that this might be connected to the alteration of corneal metabolism secondary to the lens implantation. A mathematical model of transport and consumption/production of metabolic species in the cornea is proposed, coupled with a model of aqueous flow and transport of metabolic species in the anterior chamber. Results are presented both for open and closed eyelids. We showed that, in the presence of a PIOL, glucose availability at the corneal endothelium decreases significantly during sleeping. Implantation of a PIOL significantly affects nutrient transport processes to the corneal endothelium especially during sleep. It must still be verified whether this finding has a clinical relevance.

Genome-wide identification of MST, SUT and SWEET family sugar transporters in root parasitic angiosperms and analysis of their expression during host parasitism

BackgroundRoot parasitic weeds are a major constraint to crop production worldwide causing significant yearly losses in yield and economic value. These parasites cause their destruction by attaching to their hosts with a unique organ, the haustorium, that allows them to obtain the nutrients (sugars, amino acids, etc.) needed to complete their lifecycle. Parasitic weeds differ in their nutritional requirements and degree of host dependency and the differential expression of sugar transporters is likely to be a critical component in the parasite’s post-attachment survival.ResultsWe identified gene families encoding monosaccharide transporters (MSTs), sucrose transporters (SUTs), and SWEETs (Sugars Will Eventually be Exported Transporters) in three root-parasitic weeds differing in host dependency: Triphysaria versicolor (facultative hemiparasite), Phelipanche aegyptiaca (holoparasite), and Striga hermonthica (obligate hemiparasite). The phylogenetic relationship and differential expression profiles of these genes throughout parasite development were examined to uncover differences existing among parasites with different levels of host dependence. Differences in estimated gene numbers are found among the three parasites, and orthologs within the different sugar transporter gene families are found to be either conserved among the parasites in their expression profiles throughout development, or to display parasite-specific differences in developmentally-timed expression. For example, MST genes in the pGLT clade express most highly before host connection in Striga and Triphysaria but not Phelipanche, whereas genes in the MST ERD6-like clade are highly expressed in the post-connection growth stages of Phelipanche but highest in the germination and reproduction stages in Striga. Whether such differences reflect changes resulting from differential host dependence levels is not known.ConclusionsWhile it is tempting to speculate that differences in estimated gene numbers and expression profiles among members of MST, SUT and SWEET gene families in Phelipanche, Striga and Triphysaria reflect the parasites’ levels of host dependence, additional evidence that altered transporter gene expression is causative versus consequential is needed. Our findings identify potential targets for directed manipulation that will allow for a better understanding of the nutrient transport process and perhaps a means for controlling the devastating effects of these parasites on crop productivity.

KINEROS2-based simulation of total nitrogen loss on slopes under rainfall events

Soil, water and nutrient losses are major causes of environmental pollution, with runoff accompanied by nutrient transport and sediment loss. The existing runoff and erosion models focus on estimating the total amount of pollutants in the long term. There are few studies on the process of nutrient transport during individual rainfall events, and there are still some shortcomings in the mathematical models that describe the nutrient transport process on slopes with consideration of both the dissolved and adsorbed solute in the runoff. In this study, a mathematical model was constructed for describing the nutrient transport process during individual rainfall events by combining a dissolved solute transport model and an adsorbed solute transport model. After adding the nutrient model to the runoff and erosion model KINEROS2, the runoff, sediment yield, and total nitrogen loss on slopes during individual rainfall events were simulated, and the simulation results were verified using a field experiment with different rainfall intensities and different slope lengths. The results showed that the behaviour of the total nitrogen loss was consistent with the runoff and the sediment yield. The values all first increased and then gradually stabilized, and the time to reach steady state was shortened with the increase in rainfall intensity. The runoff and sediment yield simulated by KINEROS2 were consistent with the measured data, indicating that KINEROS2 could successfully simulate the processes of runoff and erosion in runoff plots (NSE > 0.22; R2 > 0.35). Likewise, the amount of total nitrogen loss at different time points was simulated well (NSE > 0.36; R2 > 0.54). Therefore, KINEROS2 shows potential for simulating nutrients and has good applicability on the runoff plot scale in the arid and semi-arid regions of China.