Brief Summary of Minutes of Annual Meeting

Date of This Report:       30 June 2026

1. Executive Summary - NRSP11 strengthened the national framework supporting the Fertilizer Recommendation Support Tool (FRST) by expanding the relational database, advancing calibration science, and refining decision-support tools. The database exceeded 3,700 trials, sulfur data resources expanded, and national lime calibration efforts progressed, enhancing the foundation for data-driven soil-test-based recommendations.
2. Relevance to NRSP11 Mission and National Need: NRSP11 provides national research infrastructure that individual states cannot efficiently develop or maintain independently. The FRST project depends on coordinated multistate participation to compile historical and contemporary soil test correlation and calibration data, harmonize metadata and terminology, evaluate regional differences in fertilizer recommendation philosophies, and develop nationally relevant decision-support resources. This coordinated structure provides value to land-grant institutions, USDA-NRCS, private industry, agricultural laboratories, extension programs, and producers by improving access to data, promoting consistency in soil-test interpretation, and supporting science-based fertilizer recommendation frameworks.
3. Annual Meeting (8 June 2026) West Virginia University, Morgantown, WV
   1. Participants
      1. Virtual Attendees (22): Greg Buol (NC State), JC (??), Phyllis Carbone (??), Michele Francis (??), Ted Gaither (LSU AgCenter), Bryan Hopkins (BYU), Brad Joern (Precision Planting), Ashley Keough (?), Dan Kaiser (Univ Minnesota), Gene Kim (USDA-NRCS), Emma Matcham (Ohio State), Renuka Mathur (Univ New Hampshire), Stephanie Murphy (Rutgers), Nathan Nelson (Kansas State), Deanna Osmond (NC State),  Manbir Rakkar (Ohio State Univ.) Abby Reid (??), Haiying Tao (Univ Connecticut), Teferi Tsegaye (USDA), Forbes Walker (Univ Tennessee), & Matt Yost (Utah State Univ); Unknown participants include Laura (??)
      2. In-person attendees (21): Shannon Alford (Clemson), Bee Chim (Oklahoma State Univ), Gerson Drescher (Univ Arkansas), Don Edralin (NC Dept of Agric and Consumer Services), Bhupinder Farmaha (Clemson), John Filippi (Univ. Arkansas), Bronc Finch (Univ Arkansas), Robert Florence (Univ Tenn.), Luke Gatiboni (NC State), John Grove (Univ Kentucky), Quirine Ketterings (Cornell), Jay Lessl (Univ Georgia), Amber Moore (Oregon State), Rao Mylavarapu (Univ Florida), Shannon Nelson (BYU & NAPT), Rasel Parvej (Univ Missouri), Eugenia Pena (West Virginia), Vaughn Reed (Mississippi State), Raj Singh (Univ Arkansas), Nathan Slaton (Univ Arkansas), & Amy Shober (Univ Delaware)
4. Summary of Annual Meeting Minutes

1:00-3:15 pm

Nathan Slaton

Nathan presented updates on the FRST project's aspirations and database growth, highlighting plans to submit a new NRCS proposal focusing on modeling probability of response, multivariate correlations, and yield-specific calibration. He reported that the database now contains over 3,700 trials with phosphorus being the most represented nutrient at nearly 1,900 trials. The aspiration is to increase the database to over 4,000 trials in the next year while focusing on incorporating more data from the northeast and west. Details of the database growth and content across time and by nutrient, geographic region, state, and crop were provided.

Rajveer Singh

Rajveer presented on the FRST Lime Calibration Project, explaining how variations in lime recommendation methods across different states led to significant differences in lime recommendations, and outlined the standardized protocol developed for soil incubation studies to address this issue. Rajveer described the findings on soil pH and lime requirement prediction methods, noting that while buffer methods showed moderate relationships (R-squared values of 0.46-0.72), the performance was weaker than published studies conducted in specific regions. The presentation concluded that modified Mellick, modified Woodruff, and Adams-Evans buffer methods performed best, with field validation needed to confirm these relationships. John Felipe then began presenting on modeling soil test phosphorus and potassium calibration data, explaining the challenges in soil test calibration frameworks and outlining a two-step versus single-step modeling approach for estimating fertilizer nutrient rates.

John Filippi

John discussed modeling approaches for fertilizer recommendations based on soil test values: quantile regression, soil test class interval, elastic net, and CART classification regression tree. They tested four frameworks across five datasets, finding that quantile regression produced the most consistent and agronomically interpretable recommendations with continuous curves. Quantile regression at 0.5 and 0.9 quantiles, along with soil test class interval, were selected for implementation as the primary frameworks for rate calibration in the FRST decision aid.

Ana Morales-Ona Smith

Anna presented a study on variability in soil test values across different sampling inference spaces using data from 47 trials across 15 states. She focused on quantifying how phosphorus test values change when aggregated from plot to replication and field levels, finding that the median mean absolute difference was around 4 parts per million. The study also revealed that most trials had high to very high coefficient of variation in phosphorus values, with similar patterns observed in other soil properties like pH, potassium, sulfur, and zinc.

3:30 – 5:00 pm Welcome, NRSP11 Business Meeting Luke Gatiboni (NCSU)

Luke started by reviewing the achievements from the past year for the NRSP11 project, which aims to build collaborative research networks to advance soil science. Key accomplishments discussed included increasing the number of trials in the database from 3,100 to 3,700, developing a new software tool with a third nutrient (sulfur) that will be publicly available soon, and successfully conducting monthly collaborator meetings. The group also finalized a calibration study by John Philippi, published several papers and fact sheets, and submitted additional papers for publication. The meeting was set to continue with committee reports and discussions about funding opportunities and elections for the incoming chair for 2027.

Soil Depth Report – Nathan Slaton for Steve Culman, Members of the FRST team will meet with Steve next week to move the Soil Sample Depth Project forward. FRST members who contributed soil samples provided input on the information in summer 2025. The goals for project outputs include the development of 2 refereed journal papers and one data publication. The status of these outputs are:

1. The primary manuscript is partially written with the need for additional literature review, discussion of results and evaluation the regional data that should be included. Steve Culman will lead with assistance from postdoctoral candidates on literature review and discussion.
2. A second (follow-up) manuscript has near complete data analysis but needs to be developed into a manuscript. Leadership will be determined after manuscript 1 is completed.
3. The third output is to publish the data in Ag Data Commons for future use. Rajveer Singh will work with Steve Culman to develop the data publication for Ag Data Commons.

Calibration Committee Report - Luke Gatiboni, North Carolina State Univ.

The calibration committee, led by Luke Gatiboni and John Philippi, completed their work testing four different approaches after two years with a 20-member committee . The quantile regression approach using 0.5 and 0.9 quantiles was selected as the preferred method for implementation as the primary framework for rate calibration in the FRST tool, along with the soil test class interval as an alternative method. It was reported the manuscript was finished and submitted for publication to the Soil Science Society America Journal two days prior to the meeting.

Lime Calibration Report - Amy Shober/Bob Miller/Raj Singh, Univ Delaware/ALP/Univ Ark.

Rajveer Singh provided an update on the lime calibration project, noting that 148 total soils were collected with 116 used in the study (all others had pH > 6.5). The dataset with informant for all soils will be published in Ag Data Commons by the end of 2026 with multiple expected publications resulting from the rich dataset including the lime calibration and data mined from the BpH measurement labs on the density of scooped soil using different size scoops. A paper on the Pilot Lime project was submitted to the Soil Science Society America Journal the week prior to the meeting. 

Sulfur Minimum Dataset and Database - Matt Yost (virtual), Utah State Univ.

Matt Yost reported significant progress on the sulfur minimum data set, announcing that over 300 sulfur trials have been entered into the database tool, and discussed plans for a sulfur review publication with student and postdoc assistance. The discussion concluded with questions about collaborations with external groups working on the global sulfur project. Matt clarified that most of the shared sulfur data comes from legacy or published studies.

Regional CIG Reports

Northeast - Haiying Tao, Univ. of Connecticut (virtual)

Haiying Tao presented the Northeast CIG progress, noting completion of second-year trials across six states with 53 trials conducted over three years, including soil and tissue sampling for analysis. Co-PIs are entering data into templates to get it reviewed and uploaded into the FRST database.

South – Luke Gatiboni for Jim Wang, Louisiana State Univ.

Trials have been conducted in Corn, Cotton and Soybean as main crops and cereal rye and wheat as winter cover crops. Efforts were made to coordinate at least two states conducting the same trials. Currently, the project is in the last year for completing two seasons of data collection.  There was some delay in transmission of trial data to the national FRST database due to some laboratory analysis issues and uncertainty of harvest yields due to bad weather.  The project is expected to transmit all trial data by Fall 2026.

North Central - Daniel Kaiser (virtual), Univ of Minnesota.

Daniel Kaiser provided an update on the North Central CIG, reporting ongoing work at eight locations with plans to expand to around 20 locations across five states, and mentioned his leadership role in the corn N rate calculator database.

Officer Election and Wrap-up Comments

The meeting focused on funding opportunities and challenges for the NRSP 11 project. Nathan provided updates on three active funding proposals: waiting for results from a previous NIFA submission, requesting additional funding from Ag Innovation South, and preparing a new NRCS CIG proposal due in late July. The group discussed the need to better standardize soil test terminology and categories across states, with Vaughn scheduled to present on soil test variability terminology on Tuesday.

The meeting ended with a discussion on the NRSP11 leadership. During the 2025 annual meeting, Dr. Rasel Parvej (Univ. Missouri) was elected as incoming chair and he will be the chair of NRSP11 from July 2026 to June 2028. During the 2026 annual meeting it was discussed the plans to elect a new incoming chair for 2027, though no nominations were received during the meeting and the group decided to collect nominations via email and conduct online voting later.

1. Project Management/Staffing: Greg Buol (NCSU) continues serve as the programmer and decision aid modeling expert. Postdoctoral fellow Megan Bourns took a faculty position at Purdue University in August 2025. In December 2025, Dr. John Filippi was hired on the NRCS-CIG grant as a post-doctoral fellow working in Raleigh, NC under the supervision of Luke Gatiboni. Rajveer Singh continued to work in a post-doctoral fellow position in Fayetteville, AR as part of the fund matching requirement of the CIG grant.  No changes were made to the FRST Executive Team.
2. Accomplishments: Following release of the FRST decision aid, project activities focused on improving tool functionality, expanding and curating the database, and advancing calibration-related analyses.
   1. Progress Toward Objectives: NRSP11 advanced its objectives through continued database expansion, development of calibration frameworks, incorporation of sulfur datasets, progress on national lime calibration, and ongoing coordination of multistate research and outreach activities.
   2. Building Community & Stakeholder Engagement and Beneficiaries: NRSP11 engages land-grant universities, USDA-NRCS, agricultural laboratories, industry partners, extension specialists, and producers through webinars, professional presentations, monthly collaborator meetings, and project committees. These activities support information exchange, data sharing, and broader adoption of soil-test-based nutrient management approaches.
   3. Collaboration with individuals in private Industry continues to be emphasized. We currently have private industry collaborators in the NRSP11 from FFAR, Precision Planting, and Rock River Laboratories, and collaborate with the Agricultural Lab Proficiency Coordinator and the Agricultural Lab Testing Association leadership on FRST activities. Other private industry collaborations involve representatives that regularly attend the meetings but are not officially listed in NIMSS as NRSP11 participants and include individuals from Calcium Products Inc., The Fertilizer Institute, The Sulfur Institute, OCP, North America, Phospholutions, the Nature Conservancy, and Ward Laboratories. Presentations from The Sulfur Institute and Nutrien were given by Ron Olsen and Alan Blaylock, respectively.
   4. Plans for 2026-2027 include
      1. Publish the data from
         1. National lime survey, activity led by Rajveer Singh Megan Bourns
         2. OCP-NA phosphorus field trials, Ana Morales-Ona Smith
         3. Soil depth project, led by Steve Culman
      2. Publish a paper on the national lime calibration study, manuscript development led by Rajveer Singh
      3. Completing a laboratory study from 120+ soils collected by Bob Miller and collaborators using protocols established by the Lime Calibration committee and publishing the dataset, led by Amy Shober, Bob Miller & Rajveer Singh
      4. Plan a symposium for the Fall 2027 ASA-CSSA-SSSA meeting that will be held in Columbus, OH.
      5. Add a calibration model to the FRST decision tool and publish a paper on modeling soil-test calibration, led by Dr. Luke Gatiboni and John Filippi
      6. Submit proposal to NRCS for funding
      7. Continue to recruit industry representatives as participants in NRSP11
   5. Outputs
      • Produced peer-reviewed publications, fact sheets, and presentations supporting soil-test-based nutrient management.
      • Maintained and expanded the FRST website, decision aid, and user resources.
      • Conducted monthly executive and collaborator meetings (30–40 participants) to coordinate research and foster a national community of practice.
   6. Outputs
      • Produced peer-reviewed publications, fact sheets, and presentations supporting soil-test-based nutrient management.
      • Maintained and expanded the FRST website, decision aid, and user resources.
      • Conducted monthly executive and collaborator meetings (30–40 participants) to coordinate research and foster a national community of practice.
      • Outcomes summary:
        1. Short-term outcomes: NRSP11 activities increased awareness of the FRST decision aid, improved coordination among scientists working in soil test correlation and calibration, and expanded access to standardized data templates, fact sheets, and peer-reviewed information related to soil-test-based nutrient management.
        2. Medium-term outcomes: Project activities are improving consistency in approaches used to evaluate calibration data, supporting harmonization of terminology and data structures across states, and creating a stronger scientific foundation for future fertilizer and lime recommendation tools.
        3. Long-term outcomes: Continued database growth, calibration research, and stakeholder engagement are expected to improve data-driven nutrient management recommendations, enhance nutrient use efficiency, reduce uncertainty in fertilizer and lime decision-making, and support agronomic and environmental benefits across diverse production systems.
      • Group Activities In 2025-2026, committees with representatives from multiple regions were launched to
        • 1-hour collaborator meetings and an in-person annual meeting were held on 08.08.2025 (38 attendees), 09.12.2025 (36 attendees), 10.10.2025 (38 attendees), 11.11.2025 (ASA-CSSA-SSSA, 2-hour symposium with 60-80 attendees), 12.12.2025 (42 attendees), 01.16.2026 (41 attendees), 02.13.2026 (42 attendees), 03.13.2026 (31 attendees), 4.10.2026 (42 attendees), 05.08.2026 (37 attendees), & 06.08.2026 (Zoom, in-person & Zoom, 2 hours + business meeting, 43 attendees)
        • Lime Pilot Study Led by Bob Miller (independent researcher and ALP Program Coordinator) & Rajveer Singh (Univ Arkansas)
        • Lime calibration project (Led by Amy Shober, Univ Delaware, & Rajveer Singh, Univ Arkansas),
        • Develop a minimum dataset for sulfur (Led by Matt Yost, Utah State Univ),
        • Model calibration data to develop data-based P- and K-rate recommendations (Led by Luke Gatiboni, North Carolina State Univ., & John Filippi, Univ Arkansas)
        • Refine the decision support tool programming (e.g., programming committee; Led by Greg Buol, North Carolina State University).
        • Stakeholder survey (Publish data and manuscript, Led by Bourns (Purdue Univ.), Osmond (NC State Univ., retired), & Slaton (Univ. Arkansas). Committee also included two members from industry.
        • Populate the FRST database, especially for underrepresented states and crops (Bourns, Singh, Filippi, & Collaborators)
        • Review soil test terms and fertilizer recommendation strategies used by land grant institutions (Led by V. Reed, Mississippi State Univ.)
        • Soil Depth Project, (Led by Steve Culman, Oregon State Univ.)
        • OCP-NA Data Publication and data mining, (Led by Ana Ona-Morales Smith and Nathan Slaton, Univ. Arkansas, John Spargo, Penn State Univ., & Brian Bohman, OCP-NA
      • Milestones
        • Database exceeded 3,700 trials
        • Sulfur integrated into database structure
        • Stakeholder survey published
        • National lime dataset completed
        • Pilot lime manuscript submitted
        • Calibration modeling manuscript submitted

Leveraged Resources and Return on Investment: NRSP11 continues to provide substantial return on investment by serving as the collaborative framework from which competitive proposals, shared datasets, publications, and coordinated multistate research activities are developed. In addition to the four currently funded NRCS proposals, during this reporting period, FRST-related collaborations supported proposals and funded activities totaling millions of dollars in public and private investment, including NRCS-funded projects and industry-supported field research. These outcomes demonstrate that NRSP11 serves as enabling infrastructure that amplifies the value of state, federal, and partner contributions well beyond the direct support provided for the project.

• Bourns, M. (Purdue), Shober, A.L. (Univ. Delaware), Gatiboni, L. (North Carolina State Univ.), Reed, V. (Mississippi State Univ), & Slaton (Arkansas). (2025, submitted) PARTNERSHIP: Lime Logic - Standardizing lime recommendations to improve soil health and build agricultural productivity. Funding Opportunity USDA-NIFA-AFRI-011134. Purdue University Lead Institution. $866,866 (Not funded)
• In development for late July submission, Slaton, The FRST Decision Aid: Enhancing Farmer Decision-Making Through Data-Driven, Risk-Informed Soil Test Fertilizer Recommendations. Notice of Funding Opportunity No. USDA-NRCS-NHQ-CIGCLASSIC-26-NOFO0001449. $________ (TBD)
• In development for late July submission, Yost et al. (2026). Titel TBD. Western On-farm CIG. Notice of Funding Opportunity No. USDA-NRCS-NHQ-CIGCLASSIC-26-NOFO0001449 $______(TBD)

Presentations – the NRSP11/FRST Project hosted a Symposium at the 2026 CANVAS international meeting in Salt Lake City, UT and participated in other professional engagements involving stakeholders.

1. Slaton, N.A. (2025). An overview and demonstration of the Fertilizer Recommendation Support Tool [Oral]. 4R Technology Review Field Day. 17 August 2025. Springfield, OH, USA.
2. Miller, R.O. (2025, September 16). FRST Lime Pilot Project Update [Webinar]. Agricultural Laboratory Testing Association. 16 September 2025. ALTA Webinars
3. Spargo, J.T., Bourns, M.A., Buol, G., Gatiboni, L., Kaiser, D.E., Osmond, D.L., Slaton, N.A., & Yost, M.A. (2025, November 11). Fertilizer Recommendations Support Tool (FRST): A Foundation for Modernizing Fertilizer Recommendations [Invited Presentation]. Symposium--Innovative Approaches to Soil-Test-Based Fertilizer Recommendations: Fertilizer Recommendation Support Tool. 2025 Canvas ASA, CSSA, and SSSA International Meeting. Salt Lake City, Utah. 11 November 2025. https://scisoc.confex.com/scisoc/2025am/meetingapp.cgi/Paper/168854
4. Buol, G., Slaton, N.A., Spargo, J.T., Gatiboni, L., Bourns, M.A., Singh, R., & Osmond, D.L. (2025, November 11). Quantifying Probability of Soil Test Based Crop Yield Loss Using Fertility Trial Data and Kernel Density Estimation [Invited Presentation]. Symposium-Innovative Approaches to Soil-Test-Based Fertilizer Recommendations: Fertilizer Recommendation Support Tool. 2025 Canvas ASA, CSSA, and SSSA International Meeting. Salt Lake City, Utah. 11 November 2025. https://scisoc.confex.com/scisoc/2025am/meetingapp.cgi/Paper/168906
5. Gatiboni, L., Filippi, D., Slaton, N.A., Spargo, J.T., Osmond, D.L., Buol, G., Bourns, M.A., Yost, M.A., Correndo, A.A., Matcham, E., Bolster, C., Shober, A.L., Nelson, N.O, Spackman, J.A., Reed, V., Parvej, R., Flynn, R.P., Nelson, K.A., & Gan, H. (2025, November 11). Relating Soil Test Value to Fertilizer Rate: Approaches for Soil Test Calibration [Invited Presentation]. Symposium--Innovative Approaches to Soil-Test-Based Fertilizer Recommendations: Fertilizer Recommendation Support Tool. 2025 Canvas ASA, CSSA, and SSSA International Meeting. Salt Lake City, Utah. 11 November 2025. https://scisoc.confex.com/scisoc/2025am/meetingapp.cgi/Paper/168872
6. Mott, J., Reed, V., Adotey, N., Drescher, G.L., Farmaha, B.S., Jones, J.D., Kaiser, D.E., Kleinman, P.J.A., Margenot, A.J., Miner, G.L., Osmond, D.L., Phillips, S., Rakkar, M.K., Ruiz Diaz, D.A., Sadeghpour, A., Spargo, J.T., Slaton, N.A., & McGrath, J.M. (2025, November 11). Improving Soil Test P Recommendations: A Multi-Site Investigation of Source, Timing, Rate and Associated Inadvertent Nitrogen Losses. [Invited Presentation]. Symposium--Innovative Approaches to Soil-Test-Based Fertilizer Recommendations: Fertilizer Recommendation Support Tool. 2025 Canvas ASA, CSSA, and SSSA International Meeting. Salt Lake City, Utah. 11 November 2025. https://scisoc.confex.com/scisoc/2025am/meetingapp.cgi/Paper/169114
7. Yost, M.A., Slaton, N.A., Spargo, J.T., Kaiser, D.E., Gatiboni, L., Spackman, J.A., Buol, G., Jones, C.A., Mathur, R.R., Volenec, J.J., Arnall, D.B., Ruiz Diaz, R.A., & Drescher, G.L. (2025, November 11). A National FRSTt Collaborative to Coordinate Past and Future Sulfur Fertilizer Research in the United States [Invited Presentation]. Symposium - Innovative Approaches to Soil-Test-Based Fertilizer Recommendations: Fertilizer Recommendation Support Tool. 2025 Canvas ASA, CSSA, and SSSA International Meeting. Salt Lake City, Utah. 11 November 2025. https://scisoc.confex.com/scisoc/2025am/meetingapp.cgi/Paper/164990
8. Bourns, M.A., Slaton, N.A., Osmond, D.L., Spargo, J.T., Gatiboni, L., Lacey, C., & Sawyer, D. (2025, November 11). From Soil Test Data to Fertilizer Decision Making: Insights from a FRST Stakeholder Survey [Invited Presentation]. Symposium--Innovative Approaches to Soil-Test-Based Fertilizer Recommendations: Fertilizer Recommendation Support Tool. 2025 Canvas ASA, CSSA, and SSSA International Meeting. Salt Lake City, Utah. 11 November 2025. https://scisoc.confex.com/scisoc/2025am/meetingapp.cgi/Paper/168850
9. Miller, R.O., Singh, R., Slaton, N.A., & Shober, A.L. (2025, November 11). An Assessment of Lime Source, Lime Rate and Incubation Time on Neutralization of Soil Acidity. [Invited Presentation]. 2025 Canvas ASA, CSSA, and SSSA International Meeting. Salt Lake City, Utah. 10 November 2025. https://scisoc.confex.com/scisoc/2025am/meetingapp.cgi/Paper/165442
10. Singh, R., Bourns, M. A., Alford, S., Osmond, D. L., Joern, B., Jones, J. D., Kissel, D. E., Gatiboni, L., Rakkar, M., Schroeder, K. L., Yost, M. A., Moore, A. D., Kaiser, D. E., Spargo, J. T., Murphy, S., Shober, A. L., Slaton, N. A., & Miller, R. O. (2025) A National-Scale Lime Rate Calibration Effort By Fertilizer Support Recommendation Tool [Abstract]. CANVAS 2025, Salt Lake City, UT. 12 November 2025. https://scisoc.confex.com/scisoc/2025am/meetingapp.cgi/Paper/169707
11. Miller, R.O. (2025). FRST Lime Project: Results of Pilot Study of Lime Source, Lime Rate and Incubation Time on Neutralization of Soil Acidity. 2025 North Central Soil Fertility Conference Program. Des Moines, IA. 19-20 November 2025. Program At-A-Glance: North Central Soil Fertility Conference
12. Yost, M. 2025. Advancing nutrient management with the Fertilizer Recommendation Support Tool (FRST): Science, application, and impact. Department of soil and crop sciences seminar. Colorado State University. 1 Oct. 2025. Ft. Collins, CO. Invited.
13. Gatiboni, L. (2025). The FRST aid. Lecture to graduate students enrolled in SSC 541 Soil Fertility at North Carolina State University (November 2025, 16 students)
14. Gatiboni, L. (2025). Development of FRST, the Fertilizer Recommendation Support Tool. Southeast Certified Crop Advisor Training held in Smithfield (Johnston County Ag Center), NC. 9 December 2025 (~60 attendees). https://johnston.ces.ncsu.edu/event/5267794643/certified-crop-adviser-training/
15. Gatiboni, L. (2026). The FRST aid. Lecture to graduate students enrolled in SSC 541 Soil Fertility at North Carolina State University (April 2026, 14 students)
16. Slaton, N.A. (2026). FRST Fertilizer Recommendation Support Tool [Oral]. 2026 Ohio Agribusiness Association Industry Conference. Columbus, OH. 27-28 January 2026. https://oaba.net/aws/OABA/pt/sp/events_conference
17. Shober, A. & Culman, S. (2025). How Reliably Can We Estimate Soil Test Values at Different Depths? Insights from the FRST Soil Depth Sampling Project. Mid-Atlantic Crop Management School. November 20, 2025. https://extension.umd.edu/programs/agriculture-food-systems/meetings-and-events/mid-atlantic-crop-management-school/  

Publications: The NRSP11 Project produced peer-reviewed publications, datasets in Ag Data Commons, fact sheets, and updated data submission.

1. Bourns, M., Osmond, D., Slaton, N.A., Spargo, J.T., Gatiboni, L., Lacey, C., Sawyer, D., & Yost, M. (2026). Stakeholder engagement with soil testing: practices and perspectives in U.S. agriculture. Agronomy Journal, 118, e70379. https://doi.org/10.1002/agj2.70379
2. Bourns, M.A., Osmond, D.L., Slaton, N.A., Spargo, J.T., Gatiboni, L., Lacey, C., Sawyer, D., & Yost, M. (2025). Stakeholder engagement with soil testing: Practices and perspectives in U.S. agriculture [Data set]. Ag Data Commons. https://doi.org/10.15482/USDA.ADC/29656808
3. Jones, J. D., Miller, R. O., Spargo, J. T., Sikora, F. J., Rakkar, M. K., Slaton, N. A., & Osmond, D. L. (2025). Assessment of soil pH and lime requirement methods and recommended lime rates for six reference soils across U.S. land grant institutions. Soil Science Society of America Journal, 89,e70116. https://doi.org/10.1002/saj2.70116
4. Filippi, J., Gatiboni,, Buol, G., Spargo, J.T., Bolster, C.H., Bourns, M.A., Correndo, A., Gan, H., Kaiser, D., Matcham, E., Nelson, K., Nelson, N.O., Osmond, D.L., Parvej, R., Reed, V., Shober, A.L., Singh, R., Spackman, J., Yost, M.A., & Slaton, N.A. (2027). Soil test calibration frameworks for estimating fertilizer phosphorus and potassium rate recommendations for the Fertilizer Recommendation Support Team. Soil Science Society of America Journal (In Review, Submitted June 2026)
5. Singh, R., Miller, R.O., Spargo, J.T., Kissel, D.E., Shober, A.L., Gatiboni, L., & Slaton, N.A. (2027). Short‑term calcium carbonate and calcium hydroxide incubations for soil lime rate calibration. Soil Science Society of America Journal, (Submitted June 2026, In Review, Submitted June 2026)
6. Bourns, M., Osmond, D.L., Slaton, N.A., Gatiboni, L., Spargo, J.T., & Yost, M. (2026). Stakeholder Perspectives on Soil Test-Based Fertilizer Recommendations. Fact Sheet #10 (updated June 2026). https://soiltestfrst.org/resources/how-stakeholders-view-soil-testing/
7. Bourns, M., Osmond, D.L., Slaton, N.A., Gatiboni, L., Spargo, J.T., & Yost, M. (2026). Stakeholder Insights on soil sampling and fertilizer management practices. Fact Sheet #11 (May 2026). https://soiltestfrst.org/resources/how-stakeholders-view-soil-testing/
8. Singh, R., Miller, R.O., Spargo, J.T., Kissel, D.E., Shober, A.L., Gatiboni, L., & Slaton, N.A. (2026). Soil pH Response to Lime Source and Incubation Period: A Pilot Study to Guide a National Lime Calibration Project. Fact Sheet #12 (June 2026). file:///C:/Users/nslaton/Downloads/Fact-Sheet-12_Lime-Pilot-Study.pdf
9. Data Templates (revised)
   1. Phosphorus and Potassium FRST Data Submission Template (Updated 02/12/2026) https://soiltestfrst.org/resources/
   2. Sulfur FRST Data Submission Template (Updated 02/26/2026) https://soiltestfrst.org/resources/