Final report for ONC24-157
Project Information
The Western Lake Erie Basin in Northwest Ohio needs to improve on agricultural practices that reduce nutrient runoff. Nutrient runoff contributes to algae blooms in Lake Erie which have caused water quality problems. Many farmers who produce corn, soybeans, and wheat, follow crop removal nutrient rates which result in over application and nutrient runoff. Nitrogen application rates are also standardized and not reflective of soil and crop needs for economical production. Standard chemical soil testing is only one measure of the soil’s ability for crop production. By using biological testing, farmers are able to better understand what fertility practices are needed for profitable crop production while limiting nutrient runoff. Biological testing can be used to better understand the soil’s capacity for nutrient cycling and availability to the growing crop. However, many farmers do not understand what biological tests are now available and lack knowledge on how to interpret test. Results from biological testing can be used by an ag professional experienced in regenerative practices to recommend a more sustainable cropping system. This grant will conduct soil health testing, soil micro-organism testing, and crop tissue testing biology to analyze sustainable cropping systems compared to standard chemical inputs.
Project Objective
On-farm research will be conducted on a range of soil, crop rotation, and sustainable management practices.
- Soil samples and crop tissue will be collected and analyzed. Biological tests will be compared to conventional commonly used tests.
- Nutrient application adjustments will reflect recommendations from biological testing. This will compare to standard nutrient rates normally applied.
- An economic study will be conducted on both systems.
- Develop interpretations and practical recommendations for using biological testing.
- Conduct outreach with field days, agronomy reports, factsheets, and conference presentations.
Success will be determined as more cover crops are planted and less fertilizer is applied.
Cooperators
- (Researcher)
- (Researcher)
Research
Cover crop biomass will be collected and analyzed before spring termination. Cover crop biomass test was conducted by removing above ground cover crop plant growth in a 2 x 2 foot area and having it analyzed for nutrient content. This is useful to help determine cover crop termination timing. The goal is to delay termination long enough to maximize nutrient content.
After crop establishment, soil samples will be collected for analysis. In all fields, the Haney soil health test will be collected . From the same soil sample, the permanganate-oxidizable carbon (POXC) test, the WEOC test from Haney analysis, the phospholipid fatty acid (PLFA) test, and the BeCrop microbiome test will be collected for analysis.
Tissue samples will be collected at three growth stages, seedling whole plant, mid- vegetative fully formed upper leaf, and reproductive stage. Plant SAP analysis will be conducted by New Age lab, South Haven Michigan. Standard tissue analysis will be conducted by A & L lab.
Corn plots will also have stalk nitrate samples collected at black layer stage.
Two nitrogen rates on corn were compared. Corn Yield and economic return were calculated.
CORN N RATE COMPARE Dinius TEMPLATE CORN N RATE COMPARE Seiler Farms TEMPLATE (1) final Carter eFields_Data_Sheet_2024_Template
Cover Crop Biomass
In 2024 three different types of cover crops were sampled at the same time to compare nutrient content. The red clover field showed the most biomass and nutrients. In 2025 a single field was sampled 4 times from April 15 to May 30. Maximum nutrient values were on May 22.
Biomass analysis = $50
See below
POX-C & WEOC
POX-C: Permanganate oxidizable carbon (POXC) is a measure of the biologically active carbon fraction of the soil.
WEOC – Water Extractable Organic Carbon measures the most easily dissolved organic carbon compounds in soil. This represents the readily available food energy for soil microbes.
CRN = reduced rate nitrogen, Full = full or normal rate of nitrogen
Both of these tests are indicators of active soil carbon. WEOC is water extraction while POX-C is a chemical extraction. Therefore, WEOC is more sensitive to soil microbial changes than POX-C. However, both of these tests more accurately reflect soil management practices versus the total organic matter combustion test.
In this study, POX-C values were higher compared to WEOC values. This may be due to using a potassium permanganate chemical extract removing more carbon.
POX-C = $25 WEOC is part of the Haney test = $60
BeCrop & PLFA
PLFA Test: Phospholipid Fatty Acids (PLFA) are the main components of living microbial cell membranes. The PLFA test can provide a real-time snapshot of the soil microbial community.
BeCrop Test: soil microbiome analysis testing which reports soil nutrient cycling, soil health, and biodiversity.
The following samples were analyzed from duplicate soil samples.
These tests are used to determine the microbial content of soil. The PLFA can quantify the amount of microbial biomass and percentage of fungi and bacteria. This is useful to track soil management practices to improve fungi and microbe amounts. The BeCrop is more detailed giving the species of fungi and bacteria along with nutrients available. The BeCrop also gives indication of harmful microbes present.
Cost of PLFA = $60 Cost of BeCrop = $200
SAP & Tissue Tests
SAP tissue test: Sap analysis measures the active liquids in the vascular tissues, the xylem and phloem. Analysis of sap can detect nutrient issues often long before visible symptoms appear.
Tissue test – The plant tissue test will show what nutrients the plant is taking up and whether the levels are adequate for normal plant needs.
Both tests will detect if plants have enough or too much of essential nutrients even before visual symptoms occur. The SAP test compares older lower located leaf tissue compared to recently developed upper tissue. Therefore, plant nutrient movement can be tracked to monitor that upper leaf tissue has adequate nutrients. The tissue test analyzes only one tissue location on the plant.
Both tests are used to determine if supplemental nutrients are needed and optimum application timing.
In this site, 3 nutrients , N, P, and K were analyzed. Sufficient levels are shown to compare to analysis results. Multiple dates were sampled to track nutrient changes.
Less = reduced rate nitrogen, Full = full or normal rate of nitrogen
Tissue nutrient levels tended to decrease over the course of the season as the plant matured. The SAP test showed that upper new leaves tissue was higher in nutrient content, concluding that adequate movement of nutrients occurred.
The SAP test is best suited to higher value crops where frequent foliar applications are made.
SAP test = $90 Tissue test = $25
Corn Stalk Nitrate test
Corn Stalk Nitrate test: end of season test to evaluate how efficient nitrogen was utilized by the plant.
This test is an end of season checkup to determine if the corn plant had adequate nitrogen. If excess nitrogen is detected, then there may have been a surplus of nitrogen available and a reduced nitrogen rate would have been sufficient. Also, a grass cover crop would be recommended to capture the excess nitrogen available at the end of season. If below optimal levels were detected, then there was a shortage of nitrogen for the plant and yields may have suffered.
Less = reduced rate nitrogen, Full = full or normal rate of nitrogen
Stalk nitrate test = $15
Nitrogen Economics
The following tables reflect the economic return of reducing corn nitrogen rates. In only one example was the lower nitrogen rate more economical ($2.27 savings). All other fields showed that a full rate of nitrogen returned the better economics.
Carter Impact of Nitrogen (N) Fertilizer
sidedress N Rate Corn Yield Value of Grain Cost of N Return Minus N Cost
(gal/ac of 28%) (bu/ac) ($/ac) ($/ac) ($/ac)
23 178.5 $714.00 $40.25 $673.75
17 167.1 $668.40 $29.75 $638.65
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Based on $4.00/bu corn price and $1.75/gal. N cost
Dinius Impact of Nitrogen (N) Fertilizer
N Rate Corn Yield Value of Grain Cost of N Return Minus N Cost
(# N/ac ) (bu/ac) ($/ac) ($/ac) ($/ac)
168 174.4 $697.60 $30.24 $667.36
129 173.2 $692.80 $23.22 $669.58
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Based on $4.00/bu corn price and $0.18/# N cost
Dinius Impact of Nitrogen (N) Fertilizer
N Rate Corn Yield Value of Grain Cost of N Return Minus N Cost
(# N/ac ) (bu/ac) ($/ac) ($/ac) ($/ac)
160 159.0 $636.00 $28.80 $607.20
145 141.0 $564.00 $26.10 $537.90
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Based on $4.00/bu corn price and $0.18/# N cost
Seiler Impact of Nitrogen (N) Fertilizer
sidedress N Rate Corn Yield Value of Grain Cost of N Return Minus N Cost
(gal/ac of 28%) (bu/ac) ($/ac) ($/ac) ($/ac)
35 164.1 $656.40 $61.25 $595.15
25 158.4 $633.60 $43.75 $589.85
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Based on $4.00/bu corn price and $1.75/gal. N cost
Educational & Outreach Activities
Participation summary:
Factsheet - Biology Testing Options
On farm demonstrations - 4 farmers were taught how to conduct biology testing , biomass collection
Press articles in Ag media
presentations given at CTC conference, and CAP meetings
Northwest State community college workshops
Ag service providers were educated in soil health testing
Learning Outcomes
Knowledge of biological testing
Project Outcomes
By conducting biological testing, farmers are better informed what fertilizer nutrients are needed, test results may indicate a reduction of fertilizer can be done. Tracking of soil and plant biology over time will promote farmers to adopt sustainable production practices. Confidence in test results will indicate farmer acceptance of biology testing as a means to economic profitability.
A farmer stated that he felt that he was chasing the rabbit. Always adding more fertilizer inputs without economic return. His sustainable practices were confirmed by biology testing. and gave confidence to reduce inputs.