Tracer Studies Research Articles

Systems biology of electrogenic Pseudomonas putida - multi-omics insights and metabolic engineering for enhanced 2-ketogluconate production

BackgroundPseudomonas putida KT2440 has emerged as a promising host for industrial bioproduction. However, its strictly aerobic nature limits the scope of applications. Remarkably, this microbe exhibits high bioconversion efficiency when cultured in an anoxic bio-electrochemical system (BES), where the anode serves as the terminal electron acceptor instead of oxygen. This environment facilitates the synthesis of commercially attractive chemicals, including 2-ketogluconate (2KG). To better understand this interesting electrogenic phenotype, we studied the BES-cultured strain on a systems level through multi-omics analysis. Inspired by our findings, we constructed novel mutants aimed at improving 2KG production.ResultsWhen incubated on glucose, P. putida KT2440 did not grow but produced significant amounts of 2KG, along with minor amounts of gluconate, acetate, pyruvate, succinate, and lactate. 13C tracer studies demonstrated that these products are partially derived from biomass carbon, involving proteins and lipids. Over time, the cells exhibited global changes on both the transcriptomic and proteomic levels, including the shutdown of translation and cell motility, likely to conserve energy. These adaptations enabled the cells to maintain significant metabolic activity for several weeks. Acetate formation was shown to contribute to energy supply. Mutants deficient in acetate production demonstrated superior 2KG production in terms of titer, yield, and productivity. The ∆aldBI ∆aldBII double deletion mutant performed best, accumulating 2KG at twice the rate of the wild type and with an increased yield (0.96 mol/mol).ConclusionsBy integrating transcriptomic, proteomic, and metabolomic analyses, this work provides the first systems biology insight into the electrogenic phenotype of P. putida KT2440. Adaptation to anoxic-electrogenic conditions involved coordinated changes in energy metabolism, enabling cells to sustain metabolic activity for extended periods. The metabolically engineered mutants are promising for enhanced 2KG production under these conditions. The attenuation of acetate synthesis represents the first systems biology-informed metabolic engineering strategy for enhanced 2KG production in P. putida. This non-growth anoxic-electrogenic mode expands our understanding of the interplay between growth, glucose phosphorylation, and glucose oxidation into gluconate and 2KG in P. putida.

Enhancing quantitative capacity for the health sector in post-Ebola Liberia, a tracer study of a locally developed and owned coding and biostatistics program

Background Despite the demonstrated value of quantitative research in understanding and responding to public health events, analytics capability is not always prioritized or available in settings that would greatly benefit from it. In Liberia, there are no university degree-granting programs in biostatistics or mathematical modeling, promoting dependence on external technical assistance. To address the gap, a local NGO, Quantitative-Data for Decision-Making (Q4D), was founded to enhance capacity and opportunities for analyzing quantitative data among Liberians. Methods To understand the relevance, utility, and impact of the skills being taught at Q4D, a tracer study was undertaken with current and former students. Participants completed an online survey that evaluated how often and in what ways they are applying course skills, as well as any personal or professional advancement they have attributed to their learning of coding and/or biostatistics through the program. Results Among 43 participants, 81% reported a high level of confidence in independently applying skills learned through Q4D classes in their jobs and/or academic programs. Most participants (81%) responded that they were actively demonstrating the skills they acquired; 74% were teaching the skills to others. Among the 83% of employed participants who reported using the skills currently in their jobs, 56% rated the skills they learned as very or extremely useful in their current positions. Several students attributed salary increments, consultancy opportunities, and scholarships to the skills gained through the program. Conclusions Program skills are being applied by students employed in health-related sectors, suggesting that the training content is relevant and useful for addressing some of the workforce’s analysis needs. Moreover, skills built through the program have positively impacted students by preparing them with the skills required for additional employment and training opportunities to advance in-country health research capacity and reduce inequities.

Understanding the Source and Evolution of Precipitation Stable Isotope Composition across O‘ahu, Hawai‘i

Abstract Pacific Islands present unique challenges for water resource management due to their environmental vulnerability, dynamic climates, and heavy reliance on groundwater. Quantifying connections between meteoric, ground, and surface waters is critical for effective water resource management. Analyses of the stable isotopes of oxygen and hydrogen in the hydrosphere can help illuminate such connections. This study investigates the stable isotope composition of rainfall on O‘ahu in the Hawaiian Islands, with a particular focus on how altitude impacts stable isotope composition. Rainfall was sampled at 20 locations from March 2018 to August 2021. The new precipitation stable isotope data were integrated with previously published data to create the most spatially and topographically diverse precipitation collector network on O‘ahu to date. Results show that δ18O and δ2H values in precipitation displayed distinct isotopic signatures influenced by geographical location, season, and precipitation source. Altitude and isotopic compositions were strongly correlated along certain elevation transects, but these relationships could not be extrapolated to larger regions due to microclimate influences. Altitude and deuterium excess were strongly correlated across the study region, suggesting that deuterium excess may be a reliable proxy for precipitation elevation in local water tracer studies. Analysis of spring, rainfall, and fog stable isotope composition from Mount Ka‘ala suggests that fog may contribute up to 45% of total groundwater recharge at the summit. These findings highlight the strong influence of microclimates on the stable isotope composition of rainfall, underscore the need for further investigation into fog’s role in the water budget, and demonstrate the importance of stable isotope analysis for comprehending hydrologic dynamics in environmentally sensitive regions.

Beyond the Blackboard: Unveiling the Diverse Career Landscape of Education Graduates

This tracer study aimed to investigate the demographic, academic, and employment profile of 202 Bachelor of Elementary Education (BEED) graduates of Northern Iloilo State University (NISU), Philippines from A.Y 2016-2019. This study employed a quantitative approach with data collected through a modified questionnaire modeled from the Philippines’ Commission on Higher Education (CHED) Graduate Tracer Study. The findings showed that most graduates passed the Licensure Examination for Teachers and worked full-time, however, were underemployed. Most graduates acquired their first job in less than a year, but not in the field of education. The respondents found learned skills in communication, knowledge and technical, leadership, human relations, and ICT useful in the workplace to a great extent. However, research and problem-solving skills were found to be useful to a moderate extent. Among the difficulties faced by BEED graduates in finding a job, the limited job vacancies in the teaching profession or the lack of positions or permanent items in public elementary schools was pointed out as a major problem. The university is recommended to establish a dedicated unit for conducting regular tracer studies, integrate it into the college's quality assurance system, and strengthen partnerships with local employment offices and the private sector to ensure job opportunities for graduates. The Teacher Education Department may review and enhance its curriculum to align with the current demands of the teaching profession in public and private schools, both for local and international employment.

Enhancing Alumni Data Management through a Website-Based Tracer Study Application: A Case Study of Vocational High School

This research aims to evaluate the effectiveness of website-based tracer studies in collecting data on educational institutions and their alumni. The research methodology employed is A quasi- experimental design, specifically a Pretest-Posttest Control Group Design, was employed to establish cause-and-effect relationship. The result indicates that 20% of teachers met the minimum completeness criteria using the web-based application, while 80% did not. The experimental group showed improvement form pre-test to post test, meeting the minimal criteria for completeness. Challenges included difficulties in contacting alumni, which impacted data collection. The study concludes that while the web-based tracer study application is effective, challenges in alumni engagement need to be addressed for better data collection.

Modelling transport pathways of faults with low hydraulic connectivity in mudstones with low swelling capacity

Faults in some deep mudstones have poor hydraulic connectivity owing to high normal stress on the fault planes. Designing a method for modelling solute transport pathways in such faults/fractures using available data is a critical issue vis-à-vis the safety assessment of radioactive waste disposal. In this study, faults in deep siliceous mudstones with low swelling capacity are investigated using cross-hole hydraulic and tracer tests between two boreholes. The water pressures observed during the hydraulic test are reproduced via hydraulic simulations, assuming a one-dimensional (1D) flow channel with a length 8–80 times the linear distance (4.5 m) between the two borehole test sections. This flow channel length indicates a tortuosity remarkably higher than that previously reported in discrete fracture network simulations and laboratory experiments using a single fracture (i.e. 1–5). Advection–dispersion simulations using a pipe model with a tortuosity of 8–80 reproduces a time series of tracer concentrations observed during the tracer test. The radius of the pipe simulated in the tracer test was 7–39 times the flow channel radius estimated via the hydraulic test, which is in agreement with the ratio of 5–20 previously reported based on in situ tracer and hydraulic tests of faulted/fractured rocks. The simulated longitudinal dispersivity is 1/9–1/20 of the estimated flow path lengths, in agreement with the laboratory and field tracer study values. These results indicate that transport pathways in faults with low hydraulic connectivity can be modelled using a highly tortuous 1D pipe flow path.

Dimensions of program relevance towards employment success: Evidence from a graduate tracer study using principal component analysis

Dimensions of program relevance towards employment success: Evidence from a graduate tracer study using principal component analysis

Analysis on Work Status of Bachelor of Science in Biology Graduates for Curriculum Development: A Tracer Study

The research aims to assess the employment status of Bachelor of Science in Biology graduates to guide the curriculum enhancement that can meet the industry demands. Using a tracer study approach, the data was gathered from graduates. The results indicate that numerous graduates are working in sectors connected to BS Biology. The research identifies important areas for enhancement in the curriculum, such as improved hands-on experience and cross-disciplinary classes. The graduates emphasized the significance of abilities like research, laboratory methods, and critical reasoning which are essential in their careers. The study reveals that most graduates from the BS in Biology program have successfully secured employment by heeding their feedback and most of them secure full-time positions. The majority of the respondents completed their studies in 2023, with over half of them were male, 90.32% were unmarried, some are still in school, and nearly half of the respondents earn between Php10,001 - Php20,000 monthly. Around half of them held professional, technical, or supervisory roles. In addition, most graduates believed that their degree programs had equipped them with the necessary knowledge and skills to succeed in their desired professions. Moreover, the current job of the participants is fairly satisfying for the survey respondents. Recommendations from the study involve incorporating additional practical learning opportunities, cultivating relationships with professionals in the field, and consistently revising the curriculum to keep pace with evolving scientific discoveries. Thus, this research offers valuable information for schools looking to improve their biology programs, thereby better preparing the students for future careers.

The Role of Tracer Studies in Enhancing the Quality of Education: A Case in State Islamic Higher Education

A key factor in creating and improving higher education quality is data and information from tracer studies, which are also alumni feedback. Nowadays, educational institutions must to generate graduates with both academic proficiency and practical work-related abilities. This study aims to determine the extent to which the role of tracer studies in improving the quality of study programs at UIN Sunan Kalijaga. The survey approach is being used in this descriptive qualitative study. It can be inferred from survey results that data and information from tracer studies can be used as a medium for quality improvement study programs at UIN Sunan Kalijaga. These indicators included aspects of lecture activities and facilities, aspects of foreign languages, aspects of learning experiences that support work, and aspects of graduate competence.

A novel relative-equilibrium graphical plot for rapid reversible tracer studies in dynamic PET imaging

Objective. This study aims to address the issue of long scan durations required by traditional graphical analysis methods, such as the Logan plot and its variant, the reversible equilibrium (RE) Logan plot, for dynamic PET imaging of tracer kinetics. Approach. We propose a relative RE Logan model that builds on the principles of the Logan plot and its variant to significantly reduce scan time without compromising the accuracy of tracer kinetics analysis. The model is supported by theoretical evidence and experimental validations, including two computer simulations and one clinical data analysis. Main results. The proposed model demonstrates a significant linear relationship between the variable x and the slope DVT of the RE Logan plot, and the variable x′ and the slope DVT′ of the relative RE Logan plot. The Pearson correlation coefficients (r) of the linear fitting of the x′ to the x equal 0.9849 in the simulated data and 0.9912 in the clinical data. Similarly, the r values for the linear fitting of DVT′ to DVT equal 0.9989 and 0.9988 in the simulated data, and 0.9954 in the clinical data. Significance. These results demonstrate the model’s capability to maintain strong linear relationships and produce parametric images comparable to the traditional RE Logan plot, but with the considerable advantage of shorter scan durations. This innovation holds significant potential for enhancing the efficiency and feasibility of PET imaging in clinical settings.

Meta-analysis of soil and dust ingestion studies

The ingestion of soil and dust by children and adults is a potential source of exposure to environmental contaminants. To advance beyond the simple averaging of estimates used in the U.S. EPA's Exposure Factors Handbook (EFH), we describe a novel meta-analysis of all available studies that provided soil or dust ingestion estimates for children or adults conducted in the United States and Canada. Using meta-analytic techniques, we estimate the mean total soil plus dust ingestion rates and confidence intervals (CIs) for eleven age groups (0 - <1 month (m), 1 - <3 m, 3 - <6 m, 6 - <12 m, 1 - <2 years (y), 2 - <3 y, 3 - <6 y, 6 - <11 y, 11 - <16 y, 16 - <21 y, and 21+ y). These age groups were selected for consistency with the EFH update to Chapter 5 and the U.S. EPA's Age Grouping Guidance. For each age group, we calculated best estimates for the three main types of ingestion studies: tracer studies based on the aluminum tracer, biokinetic studies, and activity pattern (modeling) studies, as well as overall estimates for all three study types combined. Our meta-analysis combined study estimates using the alternative statistical approaches of the fixed effect method (inverse variance method, “I–V”) and two random effects methods, DerSimonian and Laird's method of moments (“DSL”) and the restricted maximum likelihood method (“MIXED”). For each approach, the mean total soil plus dust ingestion rate estimates for each study type generally aligned well with the EFH, ranging from 36 to 68 mg/day for infants, 56–72 mg/day for young children, and 12–32 mg/day for adolescents and adults. When all three study types were combined, the upper bounds of the 95% CI were generally the lowest for the I–V method and the highest for the MIXED method. The estimates produced here can be used for stochastic risk assessments and provide a better estimate of soil and dust ingestion rates across age groups.

MAZ-mediated up-regulation of BCKDK reprograms glucose metabolism and promotes growth by regulating glucose-6-phosphate dehydrogenase stability in triple-negative breast cancer

Tumour metabolic reprogramming is pivotal for tumour survival and proliferation. Investigating potential molecular mechanisms within the heterogeneous and clinically aggressive triple-negative breast cancer (TNBC) subtype is essential to identifying novel therapeutic targets. Accordingly, we investigated the role of branched-chain α-keto acid dehydrogenase kinase (BCKDK) in promoting tumorigenesis in TNBC. We analysed The Cancer Genome Atlas dataset and immunohistochemically stained surgical specimens to investigate BCKDK expression and its prognostic implications in TNBC. The effects of BCKDK on tumorigenesis were assessed using cell viability, colony formation, apoptosis, and cell cycle assays, and subsequently validated in vivo. Metabolomic screening was performed via isotope tracer studies. The downstream target was confirmed using mass spectrometry and a co-immunoprecipitation experiment coupled with immunofluorescence analysis. Upstream transcription factors were also examined using chromatin immunoprecipitation and luciferase assays. BCKDK was upregulated in TNBC tumour tissues and associated with poor prognosis. BCKDK depletion led to reduced cell proliferation both in vitro and vivo. MYC-associated zinc finger protein (MAZ) was confirmed as the major transcription factor directly regulating BCKDK expression in TNBC. Mechanistically, BCKDK interacted with glucose-6-phosphate dehydrogenase (G6PD), leading to increased flux in the pentose phosphate pathway for macromolecule synthesis and detoxification of reactive oxygen species. Forced expression of G6PD rescued the growth defect in BCKDK-deficient cells. Notably, the small-molecule inhibitor of BCKDK, 3,6-dichlorobenzo(b)thiophene-2-carboxylic acid, exhibited anti-tumour effects in a patient-derived tumour xenograft model. Our findings hold significant promise for developing targeted therapies aimed at disrupting the MAZ/BCKDK/G6PD signalling pathway, offering potential advancements in treating TNBC through metabolic reprogramming.

Higher education, gender, and job opportunities of engineering graduates in Ethiopia: An exploratory study

This study investigates the relationship between higher education and entry into the labor market in Ethiopia, with a focus on gender and job opportunities for engineering graduates. It uses a tracer study design to collect and analyze quantitative and qualitative data from 158 engineering graduates, 18 employers, and 16 higher education teachers. The findings suggest that higher education study conditions, curriculum relevance, and acquisition of employment skills influenced opportunities for engineering graduates to find employment shortly after graduation. In contrast to much of the existing research, our small sample of 31 female engineering graduates were not disadvantaged in comparison to males when they moved into employment immediately following graduation. Recommendations are suggested for improving the quality and relevance of engineering education to address gender gaps and challenges in higher education and employment. Future research to substantiate the findings in this exploratory study is also needed.

Alfred Otto Carl Nier: On the Shoulders of a Mass Spectrometry Giant.

This Perspective pays homage to Alfred Otto Carl Nier, whose substantial contributions were fundamental in shaping the mass spectrometry field into a key technology in research and industry. On the 30th anniversary of his passing, on May 16, 1994, this paper explores Nier's role in the field of mass spectrometry through an overview of his published works, key interviews, and archival material. Nier, originally an electrical engineer turned physicist, spent most of his scientific career at the University of Minnesota. His many innovations, both instrumental and methodological, encompassed advanced fields such as isotopic research, tracer studies, geochronology, or space research. Nier improved sector mass spectrometers, participated in the development of the isotope-ratio mass spectrometry field, developed a double-focusing sector mass spectrometer, and was a relevant member of the Manhattan Project. Today, Nier's influence persists, inspiring new generations of scientists engaged in cutting-edge research, from environmental studies to planetary exploration. His legacy thrives as current technologies and scientific strategies still echo his innovations and foresight.

A deoxyviolacein-based transposon insertion vector for pigmented tracer studies.

Pigments provide a simple means to rapidly visually ascertain the quantities or presence of specific microbes in a complex community. The selection of pigment-producing colonies that are simple to differentiate from common colony phenotypes provides a high degree of certainty for the identity of pigment-tagged strains. Successful employment of pigment production is dependent on various intrinsic factors related to proper levels of gene expression and pigment production that are not always easy to predict and vary within each microbe. We have constructed a simple transposon system that incorporates the genes for the production of deoxyviolacein, a pigment produced from intracellular reserves of the amino acid tryptophan, to randomly insert these genes throughout the genome. This tool allows the user to select from many thousands of potential sites throughout a bacterial genome for an ideal location to generate the desired amount of pigment. We have applied this system to a small selection of endophytes and other model bacteria to differentiate these strains from complex communities and confirm their presence after several weeks in natural environments. We provide two examples of applications using the pigments to trace strains following introduction into plant tissues or to produce a reporter strain for extracellular nitrogen compound sensing. We recognize that this tool could have far broader utility in other applications and microbes, and describe the methodology for use by the greater scientific community.

Enhanced dehydroaromatization of methane with methanol on Mo-ZSM-5/ZSM-11 intergrown zeolite materials

Methane dehydroaromatization (MDA) represents an appealing route for the direct utilization of abundant methane resources. Currently, the major challenge of MDA reaction lies in the rapid catalyst deactivation via coke formation, hindering large-scale industrialization of the process. Herein we report an enhanced conversion route of MDA in the presence of methanol on Mo-based zeolite materials. Compared to regular ZSM-5, ZSM-11, and their mechanically mixed counterparts, Mo embedded in ZSM-5/ZSM-11 intergrown matrix exhibits higher methane conversion (16.0%) and aromatics selectivity (62.5%) while limiting coke production to 12.1% under the co-feeding of methane and methanol (nCH4/nCH3OH = 30). If no methanol addition, coke selectivity is up to 45.1% in MDA reaction. Additionally, hydrogen enriched syngas (nH2/nCO = 6) was obtained as a co-product of the methane and methanol co-aromatization. NH3-adsorbed 1H MAS NMR, Co2+ titrated UV-vis and Raman spectroscopy characterizations reveal that a proper amount of Brönsted acid sites and the binuclear Mo anchored on the Al pairs at the intersection cavity may account for the superior reaction performance of the intergrown zeolites. A catalytic mechanism was also proposed via 13CH3OH isotopic labeling tracer and in-situ13C solid-state NMR studies. Methanol is first decomposed into CO/H2, while CO is hydrogenated to CH4 and converted into CO2 via the water-gas shift reaction. Alternatively, methanol is converted into CO/CO2 through formate intermediates. Subsequently, CO2 reduces coke deposition via the reverse Boudart reaction, which improves the catalytic performance.

Evaluating the Effects of Reduced N Application, a Nitrification Inhibitor, and Straw Incorporation on Fertilizer-N Fates in the Maize Growing Season: A Field 15N Tracer Study

Reducing fertilizer-N rate, applying a nitrification inhibitor (NI), and incorporating straw are widely recommended to improve N use efficiency of crops and decrease N losses. A field 15N tracer study was conducted to compare their effectiveness on fertilizer-N fates during the maize growing season in Northeast China. The following six treatments were used: (1) no N fertilization (control); (2) 200 kg urea-N ha−1 (100%N); (3) 200 kg urea-N ha−1 and straw (100%N + S); (4) 160 kg urea-N ha−1 (80%N); (5) 160 kg urea-N ha−1 and NI (Nitrapyrin in this study) (80%N + NI); and (6) 160 kg urea-N ha−1, NI, and straw (80%N + NI + S). The results showed that the five N fertilization treatments yielded 16–25% more grain and 39–60% more crop N uptake than the control, but the differences among the five treatments were not statistically significant. Compared with the 100%N, 20% fertilizer-N reduction (80%N) decreased the 15N concentration in topsoil and plant pools but increased the proportion of plant 15N recovery at harvesting (NUE15N, 60% vs. 50%). Compared with the 80%N, NI co-application (80%N + NI) delayed soil nitrification and increased soil 15N retention at harvesting (52% vs. 36%), thereby decreasing NUE15N significantly. Straw incorporation decreased fertilizer-N retention in soil compared with NI co-application because it promoted NUE15N significantly. In conclusion, the results demonstrate that NI and straw additions are efficient strategies for stabilizing fertilizer-N in soils and potentially minimizing N loss; however, their effects on NUE15N vary and the related mechanism must be further clarified in long-term trials.

Employability of bachelor of science in hotel and restaurant management graduates: a tracer study in LSPU Siniloan batch 2014-2021

This research aims to determine the employability of Bachelor of Science in Hotel and Restaurant Management (BSHRM) graduates from LSPU Siniloan, spanning the years 2014 to 2021. Employing a descriptive methodology, the study focuses on unbiased observation and summarization of relevant phenomena, utilizing both quantitative and qualitative approaches. The sampling technique involves 100 randomly selected respondents from the BSHRM batches, using a modified questionnaire based on the Commission on Higher Education Graduate Tracer Study. The findings present a comprehensive view of the employability landscape. Demographic analysis reveals diverse age, gender, civil status, and geographical distributions among respondents, emphasizing the need for tailored support services. Educational insights highlight the unanimous attainment of undergraduate degrees, with passion for the profession being the primary motivator for choosing the BSHRM course. Post-college training trends show a commitment to skill development, with TESDA NC2 being a key tool. Employment profiles display varied occupational roles, with a majority in the Hotels and Restaurants sector and a significant portion working abroad. Factors influencing career decisions include job retention, academic relevance, and reasons for changing jobs. This research offers valuable insights for educational institutions, employers, and policymakers to improve programs and strategies for BSHRM graduates.

Integrating Tyler and Banks' Theories in Curriculum Development: A Tracer Study Approach at UIN Sunan Kalijaga

Integrating Tyler and Banks' Theories in Curriculum Development: A Tracer Study Approach at UIN Sunan Kalijaga

Effect of ridge-furrow with plastic mulching and organic amendment on fertilizer-N fate in maize-soil system: A 15N isotope tracer study

The implementation of ridge-furrow with plastic film mulching has the potential to enhance crop yields and water productivity, particularly in black soil regions. However, the synergistic impacts of combining ridge-furrow with plastic mulching alongside with various organic amendments on maize yield and nitrogen fertilizer utilization efficiency remain unclear. Using 15N-labeled tracing technology, we investigated fertilizer-N recovery of maize, distribution, fertilizer-N residual in soil, and nitrogen fertilizer loss across six treatments: non-mulched flat with non-organic amendment (FN), non-mulched flat with straw amendment (FS), non-mulched flat with biochar amendment (FBC), ridge-furrow with plastic mulching without organic amendment (RN), ridge-furrow with plastic mulching with straw amendment (RS), and ridge-furrow with plastic mulching with biochar amendment (RBC). The results revealed that ridge-furrow with plastic mulching in comparison to non-mulched flat, led to a significant increase in maize dry biomass accumulation, yield, and the rate of fertilizer-N recovery in maize (NRE) by 8.57%–12.36%, 10.08%–15.13%, and 2.22%–3.18%, respectively. The rate of fertilizer-N residual in soil (NSR) and fertilizer-N loss (NLS) decreased by 0.5%–2.04% and 0.78%–3.21%, respectively. In addition, the straw and biochar amendments under different planting methods promoted NRE in plants and NSR in soil, reducing NLS. Compared with non-organic amendment treatments, the inclusion of straw and biochar amendments resulted in increased NRE and NRS by 1.64%–6.20% and 0.12%–2.18%, while NLS decreased by 1.76%–7.78%. Biochar amendment treatment exhibited significantly higher nitrogen accumulation and NRE compared to the straw amendment treatment. Overall, ridge-furrow with plastic mulching combined with biochar amendment proved to be an effective method to enhance nitrogen fertilizer utilization of maize in the black soil regions, improving both yield and nitrogen fertilizer utilization efficiency.