Source: UNIV OF WISCONSIN submitted to NRP
CARBON FARMING: DOES ENHANCING SOIL CARBON BOOST SOYBEAN YIELD?
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
AFRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
1030446
Grant No.
2023-67013-39817
Cumulative Award Amt.
$294,000.00
Proposal No.
2022-07306
Multistate No.
(N/A)
Project Start Date
Apr 15, 2023
Project End Date
Apr 14, 2025
Grant Year
2023
Program Code
[A1811]- AFRI Commodity Board Co-funding Topics
Recipient Organization
UNIV OF WISCONSIN
21 N PARK ST STE 6401
MADISON,WI 53715-1218
Performing Department
(N/A)
Non Technical Summary
Improving soil is a goal of farmers for both the long-term and the short-term. Improving soil health over the long-term will lead to the sustainability of their farm. However, the short-term benefits of soil improving soil health on their bottom line is unknown. There is some evidence that soils with greater soil health metrics are associated with greater soybean yield, but a complete dataset is lacking to truly know how true this is and if the effect is true outside of Wisconsin.There is a need for more research on how current soil health tests support the decisions of US Soybean farmers. Recent research in Wisconsin has demonstrated a link between POXC (a common soil health test) and soybean yield. The proposed project seeks to expand on this connection to determine other pools of soil organic carbon and soil health tests that relate to soybean yield. focused on available soil health and soil carbon indicators and how they support the decisions of soybean producers.In our study, we will utilizelong-term experiments (29 of them across the US) to connect if inherent soil properties (soil texture or pH) or if conservation management practices (such as reduced tillage or cover crops) have the greatest influence of measurements of soil health. We will then show the connection between soil health measurements and soybean yield. If shown to be true, this will provide a clear incentive for farmers to adopt conservation management practices to build their soil health, as it will benefit them by leading to greater agronomic and economic productivity.
Animal Health Component
100%
Research Effort Categories
Basic
0%
Applied
100%
Developmental
0%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1020110107070%
1021820107030%
Knowledge Area
102 - Soil, Plant, Water, Nutrient Relationships;

Subject Of Investigation
0110 - Soil; 1820 - Soybean;

Field Of Science
1070 - Ecology;
Goals / Objectives
The proposed study seeks to build more evidence for the link between soil organic matter and soybean yield. The objectives of the proposed project are to 1) Generate a dataset of soil health measures from 29 long-term soybean trials across different environments and with varying soil management treatments, including crop rotation, tillage, cover crops, and artificial drainage; 2) Identify impacts of soil management treatments on soil health measures and soybean yield at individual sites; 3) Using pooled data from all 29 sites, connect soil health measures to soybean yield and determine which pools of soil carbon, if any, are related to soybean yield; 3) Determine if local climate factors affect the relationship of soybean yield and soil health measures; 4) Generate information that will help soybean farmers understand how building soil organic carbon will impact their cropping systems.
Project Methods
This project was organized by a group of soybean Extension specialists termed "Science for Success" and recruited several other scientists for a total of 12 cooperating universities and 29 different long term research trials.Proposed activities-The long-term trials used in this study are maintained for other, ongoing research purposes, so typical maintenance of these trials will continue as usual (planting, harvest, etc.) and funded separately from this proposal. For the proposed project, we will collect soil samples to a 15 cm depth, one composite sample per plot, in spring 2023. This soil will then be air dried at room temperature and shipped to Brookside Labs in New Bremen, Ohio for analysis. Upon return of the data, soil carbon and routine soil analyses can be analyzed for each trial individually (Objective 2). Soybean yield will be collected in fall 2023 and reported to the project manager by January of 2024. Once the dataset is compiled (Objective 1), data analysis for objectives 3 and 4 will commence.Techniques (feasibility and rationale)-Long term research trials are an important and often underutilized resource. Since these trials are being maintained outside of the proposed project, conducting a wide-scale study like this one is relatively inexpensive compared to setting up and maintaining these trials. The oldest trial included in the study was established in 1911, representing an invaluable resource for information on the long-term impacts of certain cropping practices (Zhao et al., 2015).The proposed soil measurements are all available at a commercial testing facility, Brookside Labs. The soil tests include OM-LOI, SOC, WEOC, POXC, Min C, and wet aggregate stability (Table 1), in addition to routine tests for nutrient levels and pH. Typically, total SOM is quantified by a loss-on-ignition (LOI) method that burns away any organic material from a soil sample, so the lost mass is used to calculate a percentage of SOM. Since organic material is primarily composed of carbon, soil organic carbon (SOC) is often used as a proxy for SOM (Oldfield et al., 2019). Many soil health indicators focus on the fraction of SOM or SOC that is actively cycling, because this fraction tends to be more sensitive to changes in management and may be informative for crop management decisions (Morrow et al., 2016). This concept is the rationale behind choosing these five measures - they represent different pools of SOC, including water-soluble (WEOC) and recently processed (POXC) (Culman et al., 2012; Ghani et al., 2003). Soil respiration (Min C) quantifies both the pool of available organic carbon and the activity levels of microbes breaking it down (Hurisso et al., 2016). Wet aggregate stability measures how well small soil aggregates maintain their structure when wetted, representing resilience to water erosion (Hetrick et al., 2016).

Progress 04/15/23 to 04/14/25

Outputs
Target Audience:The target audience includes farmers, crop consultants, agricultural industry, and government agencies. All these groups have different interests in understanding and utilizing soil carbon and soil health measurements. Presentations were given at events that specifically target the Wisconsin and Midwest agricultural industry (fertilizers and chemical dealers and retailers) at educational conferencesand Wisconsin farmers at field days and workshops. Changes/Problems:Changes from the initial proposal included the removal of a few trials due to issues with collaborators budget constraints and insufficient labor for soil sample collection. As a result, 21 trials were used for the analyses instead of the 29 initially planned. Additionally, soil protein (ACE-N) was added to the soil health tests, alongside the originally proposed tests: total carbon, organic matter loss-on-ignition, total organic carbon, permanganate oxidizable organic carbon, water-extractable organic carbon, mineralizable carbon, and wet aggregate stability. No other major changes were made to the project. What opportunities for training and professional development has the project provided?The postdoctoral researcher, Tatiane Severo Silva, participated in group meetings with the PI, Dr. Matthew Ruark, and Co-PI, Dr. Shawn Conley, to discuss project methods, data analysis, results, and the format of data presentation. Through these meetings, she gained insights, received answers to her questions, and developed a more critical perspective. Tatiane also met with collaborators and co-authors to discuss data interpretation, presentation, and results, allowing her to consider different perspectives and insights to better interpret and report the findings. Tatiane attended various conferences, field days, and symposiums to receive educational training and expand her knowledge on soil health. These included the 2025 Wisconsin Agribusiness Classic Conference in Wisconsin Dells, WI, and the Dodge County Farmers for Healthy Soil and Healthy Water event in Columbus, WI (August 2023), where specialists and growers gave presentations and field demonstrations. She also attended soil health presentations at the 2024 ASA, CSSA, SSSA International Annual Meeting in San Antonio, TX. Additionally, through this project collaboration, she gained valuable experience in teamwork, enhancing her ability to communicate effectively, share insights, and integrate diverse perspectives into the research. How have the results been disseminated to communities of interest?The results have been disseminated to farmers, crop advisors, agricultural students, and stakeholders through field days and agronomic meeting presentations. Additionally, oral presentations at conferences and symposiums have provided opportunities to reach diverse audiences. For example, presentations were given at the 2024 Postdoc Symposium at the University of Wisconsin-Madison in Madison, WI, which included postdocs from various disciplines, including the arts and humanities, as well as the biological, physical, and social sciences. Another presentation was delivered at the 2024 ASA, CSSA, SSSA International Annual Meeting in San Antonio, TX, attended by agronomy, crop, and soil scientists, along with students, and industry professionals. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? This project provides valuable insights into how sustainable management practices impact soil health and their connection to soybean yield. By making the dataset publicly available, researchers can further explore these relationships, leading to more effective and sustainable farming strategies. For farmers and agricultural stakeholders, the findings offer practical knowledge to better understand how their management practices influence soil health, supporting informed decision-making to improve long-term productivity. Soil health management practices can also help farmers enhance profits, reduce costs, and limit risks. Beyond agriculture, this project benefits society by emphasizing the importance of sustainable farming practices in maintaining soil health. Healthier soils contribute to more resilient food production systems, ensuring a stable and sustainable food supply for future generations, while conserving our society's resources. 1) Major activities completed / experiments conducted; Soil samples were collected and analyzed for wet aggregate stability, permanganate oxidizable carbon, organic matter loss-on-ignition, mineralizable carbon, water-extractable organic carbon, total carbon, total organic carbon,soil protein, total nitrogen, pH, soil test phosphorus, soil test potassium, clay, silt, and sand content. Additionally, data analysis was conducted, followed by manuscript writing and submission to a journal. 2) Data collected; Soil samples, agronomic management field histories, and soybean yield. 3) Summary statistics and discussion of results: A meta-analysis approach was used to assess the effects of management practices on soil health parameters, and Conditional inference trees were used to identify influential factors associated with soybean seed yield. Two-crop rotations were associated with greater STP values and no-tillage was linked with lower soil pH levels. Cover cropping was associated with greater carbon-based soil health indicators (mineralizable carbon, water-extractable organic carbon), suggesting that cover crops can play an important role in building soil health in soybean-based cropping systems. Drained and undrained practices exhibited similar soil health indicators. The three most important variables influencing soybean yield, in decreasing order of importance, were planting date, soil protein, and sand content. Soil protein can be valuable indicator for soil health assessments and, in the long term, is likely to improve soybean productivity due to its association with soil organic carbon, soil organic matter, and total nitrogen. Future research should evaluate soil protein and its association with soil organic carbon pools over time to assess its reliability and impact on long-term yield outcomes and cropping system sustainability. 4) Key outcomes or other accomplishments realized. Change in knowledge: Farmers, consultants, and agronomists now know the potential value of soil health testing and improvement in soybean production. Change in practice: Cover cropping was associated with positive changes in carbon-based soil health parameters. Farmers, consultants, and agronomists are now likely to implement practices like cover cropping that will lead to improvements in soil health. Change in environment: Based on this research, we can expect to see an improvement in soil health over the long term.

Publications

  • Type: Other Status: Under Review Year Published: 2025 Citation: Silva, T. S., Malone, L. C., Ruark, M. D., Mourtzinis, S., Lee, C. D., Jordan, D., Kandel, H. J., Ross, J., Gaska, J. M., Lauer, J. G., Lindsey, L. E., Singh, M. P. Licht, M. A., Plumblee, M., Vann, R. A., Werle, R., Naeve, S. L., Roberts, T. L., & Conley, S. P. Soil health measurements and long-term management practices associated with soybean yield. Field Crops Research.
  • Type: Other Status: Under Review Year Published: 2025 Citation: Silva, T. S., Malone, L. C., Ruark, M. D., Lee, C. D., Jordan, D., Poffenbarger, H. J., Kandel, H. J., Ross, J., Gaska, J. M., Lauer, J. G., Lindsey, L. E., Singh, M. P. Licht, M. A., Plumblee, M., Vann, R. A., Werle, R., Mourtzinis, S., Naeve, S. L., Roberts, T. L., & Conley, S. P. Comparing the impacts of cover crops, tillage, and tile drainage on soil health indicators: evidence from long-term cropping system trials. Agriculture, Ecosystems, and the Environment.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2024 Citation: Silva, T. S., Malone, L., Ruark, M. D., Lee, C. D., Jordan, D. L., Poffenbarger, H., Kandel, H. J., Ross, J., Gaska, J. M., Lauer, J. G., Griesheim, K., Lindsey, L. E., Singh, M. P., Licht, M. A., Plumblee, M., Vann, R. A., Werle, R., Mourtzinis, S., Naeve, S. L., Roberts, T. L., & Conley, S. P. (2024) Soil Health Indicators Response to Long-Term Management Practices in Soybean Cropping Systems [Abstract]. ASA, CSSA, SSSA International Annual Meeting, San Antonio, TX.


Progress 04/15/23 to 04/14/24

Outputs
Target Audience:This project was discussed among farmers and crop advisors as part of extension efforts aimed at assisting farmers in making management decisions based on factors that could contribute to both their soil resilience and their farm's financial sustainability. Changes/Problems:The Brookfield laboratory, initially proposed to analyze the samples, was replaced by Regent Ag Lab due to logistical purposes and uniformity in analyses. Regent Ag Lab offered a package with all the required soil analyses. The initially proposed dataset included 29 long-term trials across different environments, but only 24 studies were included. Trials in Alabama, Louisiana, and Ontario were not sampled due to budget constraints at each location, as this grant did not allocate funds for sampling purposes. South Carolina site was also excluded due to complications in data materials transfer research agreements related to field data sharing. Although one trial in South Dakota was sampled for soil health data analyses, the crop yield was not harvested. Nevertheless, we will use the soil health data for the initial analysis, but this trial will not be included in assessing the relationship between soil health indicators and crop yield. North Carolina trials encountered issues with yield in some plots due to weed pressure and stand establishment. What opportunities for training and professional development has the project provided?One post-doctoral scholar, who commenced in March 2023, is funded by the project. This opportunity involves coordinating and organizing soil sampling and soil analysis, working with a large dataset, and gaining additional knowledge and skills in statistical analysis. Conference attendance and presentations will take place this year after analyzing the data. How have the results been disseminated to communities of interest?The project concept was presented at the Arlington Soil & AgronomyField Day August 30, 2023. The audience was farmers, crop consultants, and government agencies. What do you plan to do during the next reporting period to accomplish the goals?During the next reporting period, we will complete the analysis of the data that has been collected. Currently, we have been discussing different approaches to analyzing a dataset like this (simple machine learning, linear mixed effects models, principle component analysis).

Impacts
What was accomplished under these goals? The soil samples were collected at each location in the spring of 2023, and the samples were sent to Regen Ag Lab in Pleasanton, Nebraska. The lab concluded the soil analysis in December of 2023. After that, we combined the field data information that we obtained from each site with the soil results. Objective 1 of generating a dataset of soil health measures from 24 long-term soybean trials across different environments and with varying soil management treatments, including crop rotation, tillage, cover crops, and artificial drainage, was completed at this stage of the project. Currently, we are working on this dataset to decide the best approach for statistical analyses to accomplish objectives 2-4.

Publications