Progress 06/01/24 to 05/31/25
Outputs
Target Audience:During this reporting period, our efforts reached a diverse range of audiences across academic, professional, and industry sectors. At the College of Engineering Research Symposium at Auburn University, our team presented a poster on the current research on biochar. The symposium drew approximately 400 attendees, primarily composed of undergraduate and graduate students, faculty members, and university-affiliated researchers. We also presented our research at international conferences such as ASABE, engaging an audience of around 50 participants, including academic researchers, graduate students, and stakeholders focused on nutrient management and water resource sustainability. We also disseminated findings on MgCl?-modified biochar at the TriSociety Conference, targeting an audience of researchers, students, and professionals in fertilizer and water quality management. Communication has taken place with agricultural stakeholders involved in the production of biochar in the Republic of Ireland and Northern Ireland. In Northern Ireland, willow biochar has been produced by a local company, for use in greenhouse and field experiments. Thus, our project targets the worldwide scientific community and agricultural stakeholders in the United States, Ireland, and Northern Ireland. Changes/Problems: During this reporting period, a few modifications were made to the original research approach to address emerging challenges and expand the scope of the project. First, while initial efforts focused on modifying biochar using metal chloride salts to achieve metal oxide doping, this method was revised due to significant chlorine leaching observed during the adsorption process. The residual chlorine required additional washing steps, which added complexity and potentially impacted the biochar's surface chemistry. To address this, metal hydroxides were used instead, providing a cleaner and more efficient doping approach while eliminating the risk of chlorine contamination. Additionally, beyond the originally proposed objectives, the project scope was extended to include the application of the engineered biochar for phosphate removal from real-world wastewater, specifically, swine wastewater. This extension enhances the practical relevance of the research. Furthermore, density functional theory (DFT) modeling was incorporated to better understand the molecular-level interactions between phosphate ions and the surface-modified biochar. This computational approach is expected to provide valuable insights that can inform future optimization of adsorbent materials. Producing Mg-modified biochar in large quantities for field trials in Northern Ireland was challenging. Willow-based biochar is produced in a TLUD kiln, the efficiency and production of which is sufficient for the greenhouse experiments. However, large quantities were needed in Northern Ireland for field trials, which were difficult to produce in this way. We therefore approached a biochar producer to supply us with biochar in large quantities, so that it could be post-treated by us and our NI's partners for their field experiments. Collecting biochar from the pots after harvest was also challenging, especially at the lower rate (0.5% w/w). Therefore, in the second greenhouse experiment, it was decided to increase the amount of biochar from 0.5 to 1% w/w, so that it would be possible to collect a larger amount after harvest for isotope analysis. The start date of experimental work at AFBI was delayed due to several reasons: i) the post-doc commenced 5 months later than planned, due to completing her PhD, ii) the modification of the biochar has been a slower process than anticipated due to the large quantities required for the field experiment, and iii) the purchase of an appropriate commercial biochar product was also a slower process than anticipated, due to the large quantities required and other production issues. This resulted in a pushback to the planned date for applying the modified biochar to the field. What opportunities for training and professional development has the project provided?This project has provided valuable opportunities for training and professional development for the students, postdocs, and faculty involved. Participation in academic conferences, research symposiums, and regional career fairs provides an opportunity to significantly enhance their professional network and exposure to current research and industry trends. These events have not only allowed for the dissemination of research findings but also contributed to the development of essential communication, presentation, and networking skills, all of which are critical for future academic and career advancement. The project provides ways for the personnel to develop competencies in advanced analytical techniques and gain research skills (managing scientific literature, experimental design, precise data collection, data analysis, and written and verbal communication). How have the results been disseminated to communities of interest?The findings from this project have been actively disseminated to a broad range of communities, including students, academic researchers, technical experts, and industry stakeholders. At the university level, research outcomes were shared through several on-campus events, including the College of Engineering Symposium (2025), the Auburn University Research Symposium (2025), the Graduate School Three-Minute Thesis Competition (2025), the College of Agriculture Symposium (2025), and a departmental seminar presentation (2025). These venues provided valuable opportunities to engage with peers and faculty members across disciplines. The role of biochar in soil health was discussed at the ASC Clovis field day in August 2024 at the field site. Beyond the university, the project results have been presented at both state and international levels. Presentations were delivered at the TriSociety Conference (2024), the ASABE Annual International Conference (2024), the Alabama Water Resources Conference (2024), and the Alabama/Mississippi Water Joint Annual Conference (2025), reaching broader professional and industrial audiences involved in water quality, agriculture, and nutrient management. Project preliminary outcomes were also disseminated in the CANVAS 2024 meeting in San Antonio, TX. Peer-reviewed scientific articles are published, and some are under preparation. Planning is underway to host a knowledge transfer event for local agricultural stakeholders at our AFBI experimental field site. This will take place in summer 2025. A series of infographics and other educational materials will be produced. Also, the part of the team from the USA will be visiting the collaborator's field and greenhouse sites in Ireland and Northern Ireland in June 2025 to facilitate knowledge transfer between the project's researchers. What do you plan to do during the next reporting period to accomplish the goals?During the next reporting period, we plan to focus on applying the engineered biochar for phosphorus recovery from swine wastewater and evaluating its potential in fertilizer formulation. This will involve conducting adsorption experiments to assess the biochar's performance in capturing phosphorus from wastewater at alkaline pH conditions. The recovered phosphorus will then be used to formulate a biochar-based slow-release fertilizer. A simulated leaching experiment will be conducted to evaluate the nutrient release kinetics of the formulated fertilizer. Additionally, we will compare the performance of this wastewater-derived fertilizer to that of a similar formulation using phosphorus from conventional chemical sources to assess differences in slow-release behavior and nutrient retention efficiency. The next reporting period will also be dedicated to the more profound study of the P adsorption and desorption-related phenomena and mechanisms, following the way paved during the current research period. In particular, we will attempt to employ the developed approach to the studies of the incremental loadings of P as well as the consequent desorption studies in order to assess the preferential desorption from the surface-exposed cationic sites. We also plan to continue field demonstration, laboratory, and greenhouse experiments. Additionally, the choice experiment in the survey instrument is being finalized. The survey is expected to be ready for dissemination this coming winter, and data analysis is expected to occur before the end of Year 3 of this project.
Impacts
What was accomplished under these goals?
In the last year, we reported preparing biochar at different temperatures and conducting preliminary phosphorus adsorption experiments. We also mentioned our preparation for conducting field and greenhouse studies in the USA, Ireland, and Northern Ireland. This year, we made progress in these aspects, which are summarized below: We successfully developed a magnesium oxide (MgO)-doped biochar by pre-treating pine biomass with magnesium hydroxide, followed by pyrolysis at 450°C for two hours. The resulting engineered biochar demonstrated an adsorption capacity ranging from approximately 31 to 36 mg/g when used at a dosage of 4 g/L in phosphorus-containing solutions. We investigated the effects of contact time, ionic strength, and adsorbent dosage on phosphorus adsorption. The results showed that both contact time and dosage significantly enhanced adsorption performance, while ionic strength had a negligible influence. We evaluated magnesium leaching behavior during phosphorus adsorption in three distinct phosphate systems. Leaching remained stable over time in the initial stages of adsorption but exhibited a notable increase after four hours. At Auburn University (AU), we have also prepared Mg and Fe modified biochars using the rotary kiln at 700 oC. A total of three biochar samples, including a pristine biochar, were prepared using commercial biochar as feedstock. These biochar samples were then shipped to our collaborators at New Mexico State University and Delaware University to conduct advanced characterizations, understand adsorption-desorption kinetics, and conduct field and greenhouse studies. We conducted detailed characterizations of these samples, which include FTIR spectroscopy, ultimate and proximate analyses, cation exchange capacity, pH, and determination of trace metal contents through ICP-OES. To better understand how soil P pools isotopes can be used to distinguish biochar-source signals, we tested whether residual soil P pools can be used as tracers. Clusters of isotopes and enrichment between P pools along with C and N isotopes pointed to specific sources, and biogeochemical processes and confirmed that these P pools are more reliable proxies for identifying sources (manuscript under review). Compared amorphous and crystalline forms of calcium phosphate for dissolution in the presence of organic acids in root exudates and plant nutrition. The greenhouse plant studies showed higher crop yield and much reduced P leaching from soils with these phosphate forms than commercial fertilizer (manuscript accepted for publication). Tested adsorption and desorption of P in three biochar types (pristine, Mg-, and Fe-doped and selectivity assessed by ToF-SIMS. Spatial distribution of P with doped elements and other micronutrients found to have specific trends (manuscript in the early stage of preparation). We completed a greenhouse experiment to evaluate the impact of three different biochars from AU on sorghum growth. The analysis included soil health parameters, plant agronomic traits, and mineral nutrient concentration in different plant compartments. A field experiment was established to evaluate biochar as a soil amendment; data collection and demonstration are continued. A second greenhouse experiment is in progress, which will evaluate how the P-radiolabeled biochar absorbs and desorbs radioactive P. The experiment is set up in the USA and the UK. The survey that will be used to assess producers' willingness to adopt biochar is currently in progress. The survey structure and most of the survey questions have been finalized. At Trinity College Dublin (TCD), biochar was produced and modified with magnesium salt according to a similar procedure to that of AU.It was observed that the Mg-modified biochar had a phosphorus removal efficiency of 64-67%, compared to the pristine, which had 8-51%. Greenhouse experiments (1st and 2nd year) with perennial rye were carried out at TCD. Soil samples for both experiments were selected and analyzed for soil nutrient concentrations. Plant growth parameters (fresh and dry weight, plant height, and root mass) were measured in the greenhouse experiment. The results showed that magnesium-modified biochar treatments favored perennial rye plant growth at all rates, compared to pristine biochar. Plant phosphorus uptake was also tested. Phosphorus analysis was performed in shoots and roots after harvest. It was observed that magnesium-modified biochar resulted in higher phosphorus concentrations in shoots and roots. More specifically, modified biochar at ratios of 5% w/w and 3% w/w resulted in a 32% and 19.2% increase in shoots and roots, respectively. At AFBI, Northern Ireland, a field experiment was established in late spring of 2024 to meet the aims of Objectives 3 and 4 of this project. Commercial (unmodified) woodchip biochar was incorporated into two fields in Northern Ireland in spring 2024, followed by sowing of a spring oats crop. The two fields contained contrasting initial soil phosphorus levels. Thirty-two experimental plots were established in each field, each receiving one of eight treatments (control, NPK fertilizer, Pristine biochar, Pristine biochar + P, Pristine biochar + NPK fertilizer, P fertilizer, Blank 1, Blank 2), replicated four times. Two blank treatments were included to allow the addition of the modified biochar, produced during the project timeline. The spring oats were harvested in September 2024, followed by sowing of a winter barley crop. Soil samples were collected from each experimental plot at the start of the experiment (spring 2024) and again following harvest of the oats (September 2024). Root and rhizosphere samples were extracted just prior to harvest. Soil samples were assessed for a number of chemical and biological parameters, such as pH, carbon, nitrogen, plant available nutrients including phosphorus and potassium, active carbon, and soil functional genes. Crop yields were recorded, along with grain analysis. The winter barley crop will be harvested in July 2025, followed by the sowing of a grass crop. Modified biochar will be incorporated into the blank plots within the field experiment, and soil and crop responses will be monitored. A greenhouse study has been planned, commencing in April 2025. This experiment will be a P-isotope study, replicated across all study sites and involving all project partners. A second greenhouse study is underway to understand the interaction between biochar rate and P fertilizer rate on grass growth and yield, which is the main crop grown in Northern Ireland.
Publications
- Type:
Other Journal Articles
Status:
Under Review
Year Published:
2025
Citation:
Sharma, B., R. Ghimire, S. Sapkota, P. Shrestha, C. Brewer, and S. Adhikari (2025). Estimating the potential of agricultural and forest residue biochars to mitigate nitrous oxide emissions using long-term incubation and nonlinear kinetic models. Journal of Environmental Quality
- Type:
Other Journal Articles
Status:
Submitted
Year Published:
2025
Citation:
Evaluation of Loblolly Pine Wood Biochar Properties Derived from the Slow-Pyrolysis Process for the Synergetic Benefit of Carbon Sequestration and Soil Conditioning Journal of Analytical and Applied Pyrolysis
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2025
Citation:
Vivian Chimezie Usha, Hossein Jahromi, Pradip Adhikari, Sushil Adhikari.
Surface-Engineered Adsorbents: Tailoring Carbon-Metal Oxide Composites for Selective Dissolved Reactive Phosphorus Removal and Slow-Release. Poster presentation at the Alabama/Mississippi Water Joint Annual Conference, Mobile, AL. April 2025.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2024
Citation:
Vivian Chimezie Usha, Hossein Jahromi, Sushil Adhikari.
Application of MgO-Doped Biochar for Optimal Nutrient Capture from Farmhouse Wastewater. Oral presentation at the TriSociety Conference, November 2024.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2024
Citation:
Jaisi, D.P.
Advanced analytical methods for biochar characterization: Current usage and future promises. Annual Meeting of the Soil Science Society of America. San Antonio, TX
- Type:
Peer Reviewed Journal Articles
Status:
Accepted
Year Published:
2025
Citation:
Sakhno, Y., Vaidya, S., Nikolenko, M., White, J.C., Iafisco, M., and Jaisi, D.P. Comparative analysis of crystalline hydroxyapatite and amorphous calcium phosphate for dissolution and Plant nutrition. Journal of Nanoparticle Research
- Type:
Other Journal Articles
Status:
Under Review
Year Published:
2025
Citation:
Anton, J., Jiang, Z., Ishida, T., and Jaisi, D.P. Identification of phosphorus sources using isotope signatures of the residual phosphorus pools in soils and sediments. Soil Science Society of America Journal
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2025
Citation:
Sorrentino, L., Ivanchenko, P., and Jaisi, D.
Synthesis and characterization of hydroxyapatite nanoparticles as slow-release fertilizer. Symposium for Undergraduate Research and Creative Activity. University of Delaware, Newark, DE
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2024
Citation:
Lee, J., Rahbany, C., and Jaisi, D.P.
Tracking of transformations of phosphorus pools in agricultural soil using oxygen-18-labeled phosphate. Symposium for Undergraduate Research and Creative Activity. University of Delaware, Newark
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2024
Citation:
Vista, S., Higgins, S., Ghimire, R., Jaisi, D.P., Adhikari, S., and OConnell, D.
Effectiveness of Mg-modified biochar on P sorption and desorption in perennial ryegrass. Annual Meeting of the Soil Science Society of America. San Antonio, TX
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2024
Citation:
Vivian Chimezie Usha, Hossein Jahromi, Sushil Adhikari.
Quantifying Phosphorus Adsorption Mechanism of Magnesium-Doped Biochar for Slow-Release Phosphorus Fertilizer. Oral presentation at the Alabama Water Resources Conference, September 2024.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2024
Citation:
Vivian Chimezie Usha, Hossein Jahromi, Dale Hartman, Bijoy Biwas, Sushil Adhikari.
Evaluation of Loblolly Pine Wood Biochar Properties Derived from the Slow-Pyrolysis Process for the Synergetic Benefit of Carbon Sequestration and Soil Conditioning. Oral presentation at the ASABE Annual International Conference, Anaheim, CA. July 2024.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2024
Citation:
Jaisi, D.P.
Environmental biogeochemistry of nutrient pollution and potential technological solutions with biochar as a model. Nepal Academy of Science and Technology (NAST), Kathmandu
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2024
Citation:
Jaisi, D.P.
Methods of source tracking using isotopes in different environments, from soil to water bodies. Workshop on Microbiomes of Indoor Environment. University of Delaware- Hiroshima
- Type:
Other
Status:
Under Review
Year Published:
2025
Citation:
Educational PowerPoint Slides. These are PowerPoint slides explaining the biochar basics, their characterization, and modifying techniques. The slides also include biochars application geared towards farms.
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Progress 06/01/23 to 05/31/24
Outputs
Target Audience:During this period, the target audiences were mainly graduate students and researchers that are interested in bioenergy and biofuels production from biomass and utilizing biochar that was produced from the thermochemical conversion process. The group also interacted with several companies working on bioenergy and biochar production, where the research findings were highlighted. The results were shared through peer-reviewed journal articles. Also, the target audience for this project is agricultural producers. They will be reached by survey during the project to assess their attitudes and preferences toward biochar. Producers will also be a focus of Extension materials produced in future years of the project. Communication has taken place with agricultural stakeholders involved in the production of biochar in the Republic of Ireland and Northern Ireland. In Northern Ireland, commercial woodchip willow biochar has been purchased for use in demonstration field experimental plots. Literature searches have been completed to establish an appropriate application rate of biochar for the field experiments. Planning meetings have taken place with technical field staff at AFBI and New Mexico State University to plan the experimental protocols for the field. Changes/Problems:The production of pre-treated biochar was a very slow process and producing large quantities of biochar for field experiments and even greenhouse studies can be challenging. With our rotary kiln, the biochar yield from pine biomass is about 20% on a dry basis at 700 C. To produce 1 kg of biochar, we need about 5 kg of biomass, and it can take about one week for each sample. Therefore, we decided to dope Mg and Fe on commercial biochar to speed up the process. Once we understand the properties of metal-doped biochar, we will produce biochar from biomass in our lab. For example, our Irish collaborators soaked the raw material (willow woodchips) in two (2) different concentrations of MgCl2 (1M and 0.5M), dried, and then pyrolyzed. However, due to the Irish climate, the high humidity did not favor the rapid drying of the raw material (about 3 weeks). Thus, the production of post-treated biochar was tested. More specifically, the raw materials were pyrolyzed, and the produced biochar was cooled, crushed, and sieved. The produced biochar was soaked in 1M MgCl2 solution and then oven-dried at 80oC for 8 hours. The properties of the two engineered biochars and their effect on phosphorus adsorption and desorption will be examined so that the two production methods can be compared. What opportunities for training and professional development has the project provided?This project provided opportunities to learn research skills for undergraduate and graduate students and Post-docs. Undergraduate students learn about experimental design and data collection with accuracy. Graduate students learn analytical skills to characterize biochar and perform phosphorous sorption and desorption studies along with writing manuscripts. Post-docs assisted in biochar production using a rotary kiln, biochar modification, and testing nutrient uptake in greenhouse studies. How have the results been disseminated to communities of interest?We are at the initial stage of the project. Limited results were disseminated mainly through published peer-reviewed papers and presentations at local and national meetings. In some cases, research findings were also shared with industry stakeholders through targeted meetings. What do you plan to do during the next reporting period to accomplish the goals?In the next reporting period, we hope to make significant progress towards the project goals. First, we wanted to understand whether Mg- and Fe-doped biochars were effective in phosphorous utilization. This would be informed based on the results of ongoing greenhouse studies. Second, we will examine the role of pre-and post-modification of biochar samples using chloride salts of Mg, Fe, and Ca to generate engineered biochar. Third, the team will explore the amount of metal that can be loaded on biochar to make adsorption and desorption effective. Fourth, the team will conduct phosphorous sorption using labeled P to understand how P is being sorbed in metal-doped biochar.
Impacts
What was accomplished under these goals?
Biochar production was carried out using a rotary kiln for three different temperatures (450°C, 550°C, and 650°C) for residence time of 5-10 minutes. These samples were characterized for proximate, elemental analysis, pore size distribution, SEM, and particle size analysis. The biochar samples were used for phosphorous adsorption and results show that all biochar samples were leaching inherent phosphorous instead of adsorbing. To solve the leaching problem, we generated modified biochar samples using pre- and post-modification processes. The pre-modification was achieved by treating the pine biomass with MgCl2 salt before pyrolysis using a tube furnace for a residence time of 2 hours in a temperature range of 450°C, 550°C, and 650°C. Also, the post-modification was carried out by first producing the biochar samples using the tube furnace for 2 hours at the temperature range of 450°C, 550°C, and 650°C before treating it with MgCl2 salt. The pre-modified biochar samples were used to carry out phosphorous adsorption tests at phosphorous concentrations of 10ppm, 50ppm, and 100ppm using the UV-VIS, and more than 70% phosphorous adsorption capacity was observed for all the biochar samples tested. Field demonstration plots were established at NMSU Agricultural Science Center Clovis, and baseline soil samples were collected from the field and analyzed for various soil health parameters. AU team prepared three biochar samples (pristine, Mg-doped, and Fe-doped ) for the greenhouse trial at NMSU, and the setup is ready for the e-biochar study. A research associate is recruited to work on the experiment Characterization of phosphorus speciation on biochar prepared at different pyrolysis temperatures was done to identify the effect of physicochemical properties relevant to nutrient retention and release (in collaboration with the AU team). It was found that the ratio of readily bioavailable P to less-bioavailable P pools increased with temperature, but the amount of less-bioavailable P increased precipitously with temperature. With regard to our international partner, production of amended biochar is underway at Trinity College Dublin and greenhouse studies have commenced at Trinity College Dublin. A field experimental site at AFBI has been identified, and a suitable crop rotation has been planned (spring oats - winter barley - grass). Seeds have been purchased. Commercial biochar has been purchased for the field demonstration plots.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2024
Citation:
Sundar Sapkota, Rajan Ghimire, Prakriti Bista, Dale Hartmann, Tawsif Rahman, Sushil Adhikari. Greenhouse gas mitigation and soil carbon stabilization potential of forest biochar varied with biochar type and characteristics. Science of The Total Environment. Vol. 931. pg. 172942
- Type:
Journal Articles
Status:
Accepted
Year Published:
2024
Citation:
Bijoy Biswas, Sushil Adhikari, Hossein Jahromi, Mohamed Ammar, Jonas Baltrusaitis, Allen Torbert, John Linhoss, Jasmeet Lamba. Magnesium doped biochar for simultaneous adsorption of phosphate and nitrogen ions from aqueous solution. Vol. 358. pg. 142130
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