This proposal leverages a large NCSRP project to establish a multi-site experiment that will assess attainable yield, the effect of maturity group, and the magnitude of nutrient deficiencies for different representative localized environments across Minnesota. This information is not currently available and it will provide further insight on location-specific management across soybean cropland of the state.

Quantifying crop production capacity with available resources on every acre of current farmland is needed to guide on- ground actions by local producers to increase crop yield. The differences between soybean attainable yields and actual producers’ yields define the yield gaps. Closing the yield gaps via crop management practices provides an opportunity to increase soybean production for MN cropping systems.
The goal of the project is to benchmark attainable yield, to identify key management practices explaining the gap between producers' actual yield and attainable yield as determined by climate, soil, and genetics. At each site, the effect of the maturity group and additional fertilizer will be assessed. This information will help producers identify the factors that are preventing them from fully realizing the potential of their soybean fields and fine-tune their current management to increase yield and profit. We propose to leverage resources supplied by a new NCSRP project “Using data-driven knowledge for profitable soybean management systems” to allow us to extend the value of each on-farm research site by adding farmer and researcher implemented treatments and additional sampling and scouting at each site.

The proposed experimental approach will also contribute to the development of crop simulation tools. These models can dynamically simulate yield and other crop variables for different specific regions, for various management practices, and for current and future weather trends. Nevertheless, to be useful, simulation models must prove that they can read the variation in crop growing conditions across different environments. This proposal will also contribute to efforts to validate and recalibrate a soybean crop simulation model for the different local production environments of Minnesota. Locally calibrated and validated crop simulation models constitute a powerful tool to assess and adequate crop management practices.

1. Estimate the attainable yield for a range of representative environments across the state.
2. Understand the role of maturity group in yield determination for localized environments.
3. Identify and quantify nutrition limitation on yield for different environments.
4. Validate and recalibrate crop simulation models for local environments.

The experimental network will be integrated by 8 to 12 sites with contrasting edapho-climatic characteristics around Minnesota soybean crop land area. All the experiments will be carried out under rainfed conditions.
Crop management: The trials will be planted with the technology available by the producer. Planting date will be the earliest recommended for each site. Plant density and row spacing will be adjusted considering local recommendations and seed will be treated. Crops will be maintained free of weed, insects, and diseases. At each site, two modern varieties of contrasting maturity groups will be evaluated. Maturity group selection would change depending

on the target environment (latitude and planting date used by the producer). At each site the fertility management program will be compared against a full nutrition treatment.
Experimental design: A split plot design with at least two replicates will be used at all sites, where the maturity group will be the main plot and nutrition management the sub-plot. The plots will be sized on a farm-by-farm basis based on each farmer’s planting and harvesting equipment. The Naeve project will visit each site after planting to apply additional fertilizer treatments to ensure no fertility-based yield limitations.
• Treatment factors are presented in the table below:

Treatment Number

Treatment Number

Maturity Group

Nutrition

1 short full
2 long full
3 short control
4 long control

Field measurements:
Pre-planting characterization:
• With help from our staff, each producer will fill out a detailed (~6 page) summary of field history and current management practices as part of the larger NCSRP project. This background field data is also important for this more detailed Minnesota-specific project.
• 0-6" soil cores will to characterize texture, SOM, P, CEC, and pH;
• 0-24" soil cores will be used for initial water content, NO3, NH4, and SO4 analysis. In-season samplings:
• Biomass sampling stages will be R3 and R6, to determine crop growth rate during the critical period: 5-foot sample for recording fresh weight and number of plants;
– From the 5-ft sample, 5 whole plants will be kept (fresh and dry weight);
– From the same 5-ft sample, 5 main stems from 5 plants (fresh and dry weight).
• Fraction of soil cover at R3 and R6: Two photographs per plot taken from above and at a minimum distance of 1.5 m from the top of the canopy will be analyzed using Canopy application to obtain fraction of soil cover (%). This variable will be an estimator of the fraction of intercepted radiation that will be also useful to indirectly estimate radiation use efficiency during the critical period.
• Remote-sensed data will be captured from each site after emergence, at canopy closure, and at additional time sequences as frequently as possible. Multispectral imagery will be employed to capture NDVI as well as to evaluate for disease and water stress.
Crop harvest (R8 stage):
• Seed yield will be recorded from combine yield monitor data.
• A 2-lb seed sample per plot will be collected for seed compositional and seed size analysis. Additional information:
• Location descriptors (coordinates, previous crop, amount of residue, tillage system);
• Phenology (VE, R1, R3, R6, and R7) and fertilization records (dates);
• Weather data (temp., prec., radiation, RH, ET). Laboratorial analysis:
• Soil samples:
– as noted above.

• Seed samples:
– Protein, oil, and amino acid concentrations.

Update:
Due to a confluence of events that were largely outside of our control we were not able to make significant progress on this project this year. We have not expended any resources from this grant and plan to request a no-cost extension for FY 2023, for the full project.

The supporting NCSRP project is a very large and ambitious endeavor. Production of survey instruments intended to engage farmer audiences was not available until after our winter season. This made connecting with farmers to identify on-farm research sites in 2023 difficult. Likewise, weather delays in the spring of 2022 led to unusually high anxiety levels among farmers. We had several farmers state that they simply did not have time to assist with our project this year. We were able to line up three farmers for this project, but that did not allow a critical mass of experimental units. Late this spring we determined that it would be best to abort the mission and do it the right way in 2023. We are embarrassed that we were not able to carry out the work as promised but feel that under the circumstances that this is our best path forward.

Update:
From August report: Due to a confluence of events that were largely outside of our control we were not able to make significant progress on this project this year. We have not expended any resources from this grant and plan to request a no-cost extension for FY 2023, for the full project.

The supporting NCSRP project is a very large and ambitious endeavor. Production of survey instruments intended to engage farmer audiences was not available until after our winter season. This made connecting with farmers to identify on-farm research sites in 2023 difficult. Likewise, weather delays in the spring of 2022 led to unusually high anxiety levels among farmers. We had several farmers state that they simply did not have time to assist with our project this year. We were able to line up three farmers for this project, but that did not allow a critical mass of experimental units. Late this spring we determined that it would be best to abort the mission and do it the right way in 2023. We are embarrassed that we were not able to carry out the work as promised but feel that under the circumstances that this is our best path forward.

November update: Although we were not able carry out any of the MSR&PC supported grant, we were able to get started on the deliverables for the main NCRSP project. We were able to scout three farms in the summer of 2022. This activity helped to highlight strengths of challenges of both the NCSRP and the MSR&PC project. We used this information to help inform our plans for 2023. We plan to alter our attack on the main project as well as the state funded project and will in the end have a much better outcome, overall.

View uploaded report

Update:

View uploaded report

Update:
PM reviewed

Update:
This project received a one-year no cost extension, so this report will serve as a progress report.

Progress: We are back on track with this project. Despite working hard and twisting arms, farmers have not been willing to fill out surveys. We have tried almost everything including personal pleas to farmer leaders. Yet, we received just a handful of surveys. However... We do have enough fields to conduct the work this summer that was originally promised in this grant in 2022. We are planning to put 2 studies out in each of 7 farmers across the state. Currently, farms are centered in South Central Minnesota, so we are reaching out to farmers in SW, WC, and the RR Valley to participate. We currently have commitments from 5 farmers and will begin putting plots out in the first week of June, 2023.

This project will allow us to generate science-based recommendations to Minnesota soybean growers so they can maximize yield for different localized environments across the state.
Identification of yield gaps relative to management and environment will allow for tailored recommendations by extrapolation across the state of Minnesota.
Results will help to more precisely determine optimum cultivar maturities by location across the state.
Results will identify frequency and soil and climatic environments where nutrient deficiency is limiting soybean yield.
Minnesota growers will have a calibrated and validated simulation tool to assess future questions.