Brief Summary of Minutes of Annual Meeting

The 2025 meeting was held in a hybrid mode. 6 people attended the meeting in person in Kansas City, Missouri, and 9 people attended the meeting virtually via Zoom.

• Welcome, Introduction, approval of 2024 meeting minutes with no changes or discussion, review of meeting agenda.
• Highlight: Multiple new investigators joined the NC1195 team across different states including Natasha Rayne (UW-Madison), Michael Castellano (Iowa State Univ), Ali Nafchi (South Dakota State Univ), Alexandra Huddell (Univ. of Delaware), and Alex Woodley (NC State Univ.)
• State reports. Four in-person and six virtual attendees gave 20-35 minutes presentations about their work relevant to the overall project theme, followed by a discussion of each topic area:
• Xia Zhu-Barker (University of Wisconsin-Madison): Crop and soil N response to manure and a winter rye cover crop.
• Peter Tomlinson (Kansas State University): Kansas report
• Javed Iqubal (University of Nebraska-Lincoln): In-Season Nitrogen Management for Irrigated Corn
• Debasish Saha (University of Tennessee): Long-term cover cropping and nitrogen fertilization impacts on soils’ net GHG balance under continuous no-till cotton cropping system
• Will Horwath (University of California Davis): Evaluating the interaction between organic amendments and fertilizer N under different environmental conditions
• John Jones (University of Illinois Urbana-Champaign): Corn nitrogen research, outreach, and fertilizer recommendation updates
• Jeanette Norton (Utah State University): Contrasting Nitrogen Source Impacts Nitrogen Use Efficiency and Soil Health Indicators under Silage Corn Production in a Semi-Arid Environment
• Michael Castellano (Iowa State University): The Iowa Nitrogen Initiative
• Ali Nafchi (South Dakoda State University): On-farm Research, Virtual Yield Mapping System and N Management
• Alexandra Huddell (University of Delaware): Cover crop biomass and heterogeneity effects on nitrogen processes
• Alex Woodley (NC State University): NC report
• Key discussions: 
• Collaborative use of the existing regional data to develop decision tools and publications
• Meeting in 2026: The group agreed to hold the next meeting on February 19-20, 2026, at Fairfield Inn and Suites, Kansas City, MO. (Motion: Peter Tomlinson; Second: Xia Zhu-Barker; Motion Approved)
• Executive Committee Changes: The current Secretary, Peter Tomlinson, will be the Chair in 2026; the current Member-at-Large, Xia Zhu-Barker will be the Secretary. The current Chair, Debasish Saha, will be the past Chair.

1. Impact Nugget:

Advancements

This research project has advanced our understanding of how emerging management practices, such as cover cropping and innovative manure processing technologies as well as environmental stressors like drought and excessive precipitation, influence nitrogen dynamics, nutrient use efficiency, soil and environmental health, and overall profitability in corn-based cropping systems. Project members developed practical tools and guidelines, including the Nitrogen Rich Biosensor Spot (NRBS) methodology that combines biosensors, satellite imaging, and field data, to support precision nitrogen management, create variable rate application maps tailored to field-specific variability, and improve nitrogen use efficiency using in-season remote sensing data.

Accomplishments

Drawing on multi-year, multi-state research, the project evaluated and optimized: i) the economic optimum nitrogen rate (EONR) for corn and associated soil biological health processes under varying cover cropping and manure management practices; ii) nitrogen rate and timing strategies to enhance profitability and sustainability under variable precipitation patterns and biophysical constraints (e.g., drainage limitations); and iii) the potential of alternative nitrogen sources, such as compost and processed manure, to reduce reliance on synthetic fertilizers, improve crop yields, and lower the carbon and nitrogen footprints of agricultural systems. To support these goals, the team established experimental field trials across multiple regions such as Commercial Nitrogen Optimization Pilot Grant Program (NOPP) in Wisconsin, conducted outreach through field days and workshops, developed decision support tools such as FACTS in Iowa, and created the NRBS methodology, which integrates biosensors, satellite imaging, and field data to generate actionable insights in South Dakoda, field specific nitrogen application maps, and in-season remote sensing strategies that improve nitrogen use efficiency.

Impacts

The multi-state project team generated critical insights to guide producers and consultants in adopting alternative nitrogen management practices, such as optimized application timing, accounting for cover crop effects on EONR, and the use of artificial drainage, composts, and processed manure. These practices support improved nitrogen use efficiency, greater resilience to climate variability (particularly precipitation), and enhanced profitability—key components of sustainable and regenerative agriculture in the U.S.

2. New Facilities and Equipment.

• Michael Castellano (Iowa State University) developed a web-based tool for yield prediction (FACTS; https://facts.extension.iastate.edu)
• Zhu-Barker (University of Wisconsin-Madison) installed nitrate and oxygen sensors in the long-term water quality monitoring station to monitor nitrate leaching and understand the fate of nitrate in soil profile from various cropping systems in Wisconsin.

3. Unique Project Related Findings. List anything noteworthy and unique learned this year.

• Corn maximum yields have lower optimum N rates with manure (average 94 kg ha^-1 lower) compared to no manure.
• Cover crop increases optimum N rates, regardless of manure application.
• Optimum N rates with and without manure are not different with a rye cover crop
• Solid manure increases fertilizer N retention in soils.
• Long-term (42-year) legume cover cropping and nitrogen fertilization increased soil carbon stock in a continuous cotton system, but also increased N₂O emissions, which could offset on average 116% (range 38 to 254%) of the soil carbon sequestration benefits
• Farmers using the NRBS approach reduced nitrogen fertilizer applications by up to 15% and field trials showed significant improvement in NUE (10–80% in different zones) by using NRBS approach. 

4. Accomplishment Summaries.

Determine the roles of innovative management practices, the environment, and their interactions on the optimum use of nitrogen in agroecosystems.

• Project members showed how practices like manure application and planting winter rye cover crops affect how much nitrogen fertilizer corn needs. The results reveal that using manure can reduce the need for added fertilizer, while cover crops tend to increase it. Project members also tested new manure processing methods that separate solids from liquids, which may help reduce environmental risks while still supporting strong crop yields. Project members also successfully established experimental field trials in multiple states (e.g., South Dakoda and Wisconsin) to test multiple nitrogen rates and application strategies.

Understand the role of soil biological processes in controlling plant available nitrogen and their relationships with soil health and system resilience.

• By tracing how nitrogen moves through the soil and into crops, project members learned how fertilizer gets stored in different parts of the soil and how much is taken up by plants. This helps us understand how soil organisms and organic matter influence nitrogen availability, soil health, and the long-term resilience of farming systems.

Translate field and laboratory research into nitrogen management decision-making tools and educational resources promoting improved profitability and sustainability of corn-based cropping systems.

• Michael Castellano (Iowa State University) and multistate project members developed decision-support tools (FACTS) that integrate public weather and soil data with field experiments, crop simulation modeling (APSIM), and advanced analytics (e.g., machine learning, GIS). These tools benchmark nitrogen and water conditions, guide corn and soybean management decisions, and enhance predictive capabilities. By translating research into scalable, data-driven resources, the project aims to help farmers make informed nitrogen decisions that improve profitability and sustainability in corn-based systems.
• To boost the adoption of NRBS methodology, Ali Mirzakhani Nafchi (South Dakoda State University) engaged over 50 stakeholders and demonstrated the improved nitrogen use efficiency and yields through biosensor-satellite detection and optimized application rates.
• Xiaofei Li (Mississippi State University) examined different methods to estimate site-specific corn yield responses to nitrogen, and their applications in deriving site-specific optimal nitrogen rate recommendations.

• Curtright, A., D Zapta-Rojas, R. Horwath, X Zhu-Barker. 2025 Quantifying nitrogen provisioning and release from cover crops in walnut orchards. Agriculture, Ecosystems & Environment 383, 109529
• Moore, E.B., M De, M.R. Nunes, D Saha, V Jin, L Li, J.M.F. Johnson, D.L. Karlen, D. McDaniel. 2025. Connections between roots and soil health across agriculture management practices. Plant And Soil, doi.org/10.1007/s11104-025-07367-w
• Mieno, T., Li, X., and Bullock, D. S. 2024 Bias in Economic Evaluation of Variable Rate Application based on Geographically Weighted Regression Models with Mis-specified Functional Form. Journal of the Agricultural and Applied Economics Association, 3(1), 135–151. https://doi.org/10.1002/jaa2.102
• Park, E., Brorsen, W. B., and Li, X. 2024 Using Data from Uniform Rate Applications for Site-Specific Nitrogen Recommendations. Journal of Agricultural and Applied Economics, 56(1), 138–154. https://doi.org/10.1017/aae.2023.44
• Dew, J., Li, X., Oglesby, C., Fox, A., Sharma, R., Singh, G., McCoy, J., Kaur, G., Gajula, P., and Dhillon, J. 2024 Assessing the Effect of Cultural Practices on Mississippi Corn Production 1: Grain Yield. Crop, Forage, & Turfgrass Management, 10(1), e20267. https://doi.org/10.1002/cft2.20267
• Sharma, R.K., Dhillon, J., Oglesby, C., Gajula, P., Bheemanahalli, R., Li, X., Cox, M.S., Reed, V. and Reddy, K.N. 2024 Corn Response to Multiple Rates of Nitrogen and Sulfur. Field Crops Research, 319, 109625. https://doi.org/10.1016/j.fcr.2024.109625
• Mirzaee S, AM Nafchi. 2025 Enhancing NUE in corn through optimized sensor-based prescription maps. Sensors, accepted.
• Mirzaee S, AM Nafchi. 2025 Advancing global nitrogen use efficiency for environmental sustainability. Land Degradation and Development 1-12.
• Kumari K, AM Nafchi, S Mirzaee, A Abdalla. 2025 AI-driven future farming for achieving climate-smart and sustainable agriculture. Agriengineering 7, 89.
• Mirzaee S, AM Nafchi, Y Ostovari, M Seifid, S Ghorbani-Dashtakie, H Khodaverdiloo, S Chakherlou, R Taghizadeh-Mehrjardi, B Raei. 2024 Monitoring and assessment of spatiotemporal soil salinization in the Lake Urmia region. Environmental Monitoring and Assessment Journal 196, 958.
• AM Nafchi, J Clark, S Mirzaee. 2023 Monitoring corn nutrient deficiencies: the traditional and precision ag approach. SDSU Extension Factsheet.
• AM Nafchi, Y Askarzadeh, S Mirzaee. 2024 Cover crops in modern agriculture. SDSU Extension Factsheet.
• Mirzaee S, AM Nafchi. 2024 Pros and cons of yield goal-based variable rate nitrogen prescription maps. Innovations in Precision Agriculture Session, ASABE Annual International Meeting.
• Mirzaee S, AM Nafchi. 2024 Enhancing nitrogen use efficiency and crop yields integrating biosensors-rich spots and remote sensing. Latest Developments in Precision Crop Protection and Fertilizer Applications Session, ASABE Annual International Meeting.