Ohio Department of Agriculture Reminds Pesticide Applicators of June 30 Cutoff Date for Dicamba Products

The Ohio Department of Agriculture (ODA) is reminding pesticide applicators of the June 30 cutoff date for over-the-top dicamba products to soybeans. No additional applications can be made to this year’s crop after this date, regardless of growth stage.

Dicamba is an herbicide used to help limit unwanted weeds around crops. In 2018, the Environmental Protection Agency (EPA) designated new dicamba products as restricted use, meaning they can only be used by certified applicators.

In December 2021, the EPA released its 2021 incident report, which indicated that across the United States “more than 1 million acres of non-dicamba-tolerant soybean crops were allegedly damaged by off-target movement of dicamba.” In Ohio, there were 34 reported incidents involving dicamba.

If you have questions or concerns about dicamba please contact the Division of Plant Health’s Pesticide & Fertilizer Regulation Program at (614) 728-6987 or Pesticides@agri.ohio.gov.

Estimated and Soil Test Methods to Determine Supplemental N need after Flooding

Determining the amount of supplemental nitrogen, if any, that is needed after saturated soil conditions is a difficult question to answer. Soil conditions such as texture, temperature, and length of saturation plus nitrogen application factors timing, placement, source, inhibitors used along with the growth stage of corn which impacts the amount of N already taken up, affect the decision to apply additional N.

In Ohio, we have long used a tool adapted from the University of Minnesota that walks through five key questions. Points are assigned based on the answers to the questions posed and lead you to a recommendation. The tool is found in Bulletin 827 Corn, Soybean, Wheat, and Forages Field Guide (2019) on pages 81 and 82 or here. Given the current price of nitrogen and widely varying field conditions, an understanding of loss mechanisms and other estimates of loss or soil tests may help decide on 2022 management in fields where N has already been applied.

N Loss Mechanisms

The two primary loss mechanisms are leaching N below the soil root zone and denitrification with heavy rain and flooding. Leaching occurs with the nitrate form of N and is more typical on coarse-textured or sandy soils. Fine-textured soils with poor drainage where ponding occurs are where denitrification is most likely. Bacteria in the ground will use the oxygen from the nitrate molecule resulting in nitrogen gas. N gas formed is lost to the atmosphere. Bacteria will begin the denitrification process within two to three days of soil saturation (Lee et al., 2007).

Impact of N form applied

Nitrogen in the nitrate form is subject to leaching or denitrification losses. However, our fertilizer sources are a mix of nitrate and ammonium. The conversion of ammonium to nitrate requires time and the time needed depends upon soil temperatures and the use of a nitrification inhibitor. Using a nitrification inhibitor (e.g., nitrapyrin) can help delay the conversion of fertilizer nitrogen into the nitrate form. A nitrification inhibitor can potentially delay the conversion of ammonium to nitrate by 2 to 6 weeks, depending on environmental conditions (Omonode and Vyn, 2013; Havlin et al., 2014). However, this conversion delay is likely closer to 2 weeks at this point in the growing season due to warmer soil temperatures. A urease inhibitor can delay the conversion of urea to nitrate by 7 to 10 days.

Table 1. Approximate time until fertilizer nitrogen is in the nitrate form (Havlin et al., 1999)

Fertilizer Source Approximate Time Until Ammonium Approximate Time Until Nitrate
Ammonium sulfate, 10-34-0, MAP, DAP 0 weeks 1 to 2 weeks
Anhydrous ammonia 3 to 8 weeks
Urea 2 to 4 days 1.25 to 2.5 weeks
UAN 50% from urea in 2 to 4 days
25% is ammonium, 0 weeks
50% in 1.25 to 2.5 weeks
25% in 1 to 2 weeks
25% is nitrate, 0 weeks


Estimating Denitrification Losses

Soil temperature and how long soil is saturated also influence the amount of nitrate lost from denitrification. At soil temperatures between 55 to 65 degrees Fahrenheit, approximately 2 to 3% of soil nitrate is lost per day under saturated conditions. If the soil temperature exceeds 65 degrees Fahrenheit, around 4 to 5% of the soil nitrate is lost daily. Also, remember it takes approximately 1 to 2 days for saturated soil to reach anaerobic conditions.

Let’s think through an example where we made a side-dress application of 28% UAN at 150 lbs N/acre three weeks ago. Table 1 suggests that 100% of the UAN is now in nitrate form. If saturated soil conditions exist for 6 days with soil temperatures greater than 65 degrees, we expected a 20% loss [5% per day X 4 days (subtracted 2 days for the lag time until a saturated soil reaches anaerobic conditions)] of the 150 lbs N/acre was denitrified or lost (approximately 30 lbs N/acre). These calculations are strictly estimates and may not reflect actual N losses since so many factors interact in nitrate conversion and loss from the soil. An additional consideration is that corn submerged or ponded for 3 to 4 days may experience significant root damage, limiting supplemental nitrogen application benefits.

Estimating Leaching Losses

Determining the amount of N loss from leaching, like denitrification, also depends on the amount of nitrogen fertilizer applied in the nitrate form (Laboski, 2016) (Table 1).

Using an example of 150 lbs of N/acre of UAN containing a nitrification inhibitor applied 1 week ago in a side-dress application, only 25% of the UAN is likely in the nitrate form. Therefore, approximately 37.5 lbs N/acre has the potential to be leached with heavy rainfall. Keep in mind the crop has also taken up some nitrogen since application, so the potential N leaching loss is less than 37.5 lbs N/acre. Furthermore, nitrogen leaching is also dependent on soil drainage patterns and the total amount of water required for soil to reach field capacity (White, 2018). More significant nitrogen leaching loss is likely to occur on coarse-textured, sandier soil types than on fine-textured, loam, and clay soil types. Established rooting depth is also necessary to estimate potential nitrogen loss from leaching. Just because nitrogen has moved downward in the soil profile doesn’t mean the nitrogen has moved out of the root zone. This is especially true in seasons where dry conditions occur early and rooting depth increases.

With delayed planting and side-dressing in 2022, considering the timing of nitrogen applications compared to when flooded conditions existed in your fields is important to answer the question of if any supplemental N is needed?

Can a Pre-Sidedress Nitrogen test provide a better answer?

Taking the time to soil test, which gives a number to develop a recommendation, is an option for quantifying soil available N. For many years, the Pre-sidedress Nitrogen Test (PSNT) has been a valuable tool in making nitrogen recommendations in manured fields. Camberato and Nielsen, 2017 shared their thoughts on using a PSNT test to assess soil N availability from previous fertilizer applications.

Chart, scatter chart Description automatically generatedThe PSNT sampling method is to take 12-inch deep cores from representative areas of the field. Where fertilizer N was broadcast-applied rather than banded, collect 20 to 30 random soil cores per sample. If fertilizer N was banded rather than broadcast-applied, collect 15 to 20 groups of 5 soil cores each that proportionally represent areas with and without banded fertilizer. Take one core in the center of the band, then two cores on both sides of the center at a quarter and half of the band spacing.

The lab results showing either a nitrate (ppm) or nitrate plus ammonium (ppm) can be compared to expected N levels shown in Table 2. The recommendation is If the corn is healthy and the growing season is expected to be typical from here on out, they suggest applying no more than 10 pounds of N for every 2 ppm reduction in soil sample N below the expected levels listed in Table 2.Table 2

Table 2

Recognize that as a healthy crop moves through the rapid growth phase before pollination, soil N levels will naturally decrease in response to rapid N uptake by the plants. However, by the time a healthy crop reaches the V9 leaf stage (about 30 inches tall), only 19 lbs/ac N (equivalent to 5 ppm soil NO3-N in a 1-foot deep sample) have typically been taken up by the plants (Mengel, 1995). But, by the time a healthy crop reaches shoulder-high (~V15 or 60 inches tall), approximately 116 lbs/ac N (equivalent to 29 ppm soil NO3-N in a 1-foot deep sample) have been taken up by the plants. With later corn, the amount of N in the plant should be considered when evaluating soil N.


Lee, C., J. Herbek, G. Schwab, and L. Murdock. 2007. Evaluating Flood Damage in Corn. AGR-193. University of Kentucky Cooperative Extension Service. http://www2.ca.uky.edu/agcomm/pubs/agr/agr193/agr193.pdf

Omondoe, R.A., and T.J. Vyn. 2013. Nitrification Kinetics and Nitrous Oxide Emissions when Nitrapyrin is Coapplied with Urea-Ammonium Nitrate. Agron. J. 105:1475-1486.

Havlin, J.L., J.D. Beaton, S.L. Tisdale, and W.L. Nelson. 1999. Soil Fertility and Fertilizers. An Introduction to Nutrient Management. 6th ed. Prentice Hall. Upper Saddle River, NJ.

Havlin, J.L., S.L. Tisdale, W.L. Nelson, and J.D. Beaton. 2014. Soil Fertility and Fertilizers. An Introduction to Nutrient Management. 8th ed. Prentice Hall. Upper Saddle River, NJ.

Quinn, D. 2021. Should Supplemental Nitrogen Be Applied To Corn Following Heavy Rainfall?. Pest and Crop Newsletter. Purdue University. https://extension.entm.purdue.edu/newsletters/pestandcrop/article/should-supplemental-nitrogen-be-applied-to-corn-following-heavy-rainfall/

Camberato, J and R. Nielsen. 2017. Soil Sampling to Assess Current Soil N Availability. Purdue University. https://www.agry.purdue.edu/ext/corn/news/timeless/AssessAvailableN.html

Crop Observation and Recommendation Network

C.O.R.N. Newsletter is a summary of crop observations, related information, and appropriate recommendations for Ohio crop producers and industry. C.O.R.N. Newsletter is produced by the Ohio State University Extension Agronomy Team, state specialists at The Ohio State University and the Ohio Agricultural Research and Development Center (OARDC). C.O.R.N. Newsletter questions are directed to Extension and OARDC state specialists and associates at Ohio State.

Agronomy Breakfast Series Pt. 1

Want to know the best way to start the day? FREE BREAKFAST! That’s right FREE BREAKFAST! Join Adams Brown Clermont & Highland Farm Bureau and OSU Extension Brown County for the first part of the Agronomy Breakfast Series this Friday, June 10, 2022 from 8:00am-9:00am. During this one hour session participants will get FREE BREAKFAST, 30 minutes of Privat Pesticide Category CORE recertification, 0.5 CCA Continuing Education Unit: Integrated Pest Management and updates on field research from OSU Extension Brown County. If you are wanting to attend this FREE event today is the last day to register. Participants can register by calling the Brown County Extension Office at 937-378-6716 or by emailing Amanda Perkins at perkins.715@osu.edu. We look forward to seeing you there!                                                                                                                                                                                                                                                                                                                                 















Black Cutworm Trap Update

This was the 2nd week for our Black Cutworm Trap. This week we collected 7 adult moths. Understanding BCW numbers before planting will help identify regions that may be at increased risk for BCW. As planting continues and trap numbers increase, plan to monitor for BCW larvae after corn is planted, especially in fields with a lot of broadleaf weeds, such as chickweed and purple dead nettle. You can learn more here.

Agronomy Breakfast Summer Series & On Farm Research Tour

Are you looking for something to do this summer? Look no further this summer there will be the Agronomy Breakfast Series and an On-Farm Research Tour. The series will consist of 2 sessions held on Friday, June, 10 and Friday, July 8, 2022  and the On-Farm Research tour will take place on August 27, 2022. These events are open to the public and are FREE for Brown County Producers. Non-Brown County Producers will be charged $10/hr for pesticide credits and will not be charged until after the events have been completed.

 Agronomy Breakfast Series:
          When: Friday, June 10 & July 8, 2022 from 8:00-9:00am
Where: Brown County Fairgrounds: Ag. Administration Building (Next to Farm Bureau Office) 325 W. State St. Georgetown, OH, 45121
Registration: REQUIRED Participants can register online at Agronomy Breakfast Series.
Cost: Free for Brown County Producers, $10/hr. for Non-Brown County Producers (Payments will be collected after the series has concluded)
Friday, June 10, 2022 will include:
30 minutes of Private Pesticide Category CORE recertification
0.5 CCA Continuing Education Unit: Integrated Pest Management
Brown County Extension insect monitoring update: black cutworm, true armyworm, fall armyworm, western bean cutworm, european corn borer, and corn earworm.
Additional reports from the field (insect, weeds, disease).
Friday, July 8, 2022 will include:
30 minutes of Private Pesticide Category CORE recertification
0.5 CCA Continuing Education Unit: Integrated Pest Management
Brown County Extension field reports (insect, weeds, disease).

On-Farm Research Tour:
          When: Saturday, August 27, 2022
Where: Fussnecker Farms- 10068 Hamer Rd., Georgetown, OH 45121
Dailey Farms- 1193 Fite-Hauck Rd., Sardinia, OH 45171
Registration: REQUIRED Participants can register online at On-Farm Research Tour
Cost: Free for Brown County Producers, $10/hr. for Non-Brown County Producers (Payments will be collected after the event has concluded)
Fussnecker Farms- Here participants will be ale to receive:
30 minutes of Private Pesticide Category 1 (grain and cereal crops) recertification
0.5 CCA Continuing Education Units (Integrated Pest Management)
Overview of Fussnecker Farm’s/OSU Extension’s on-farm research plat: Soybean Fungicide
Dailey Farms- At this tour spot participants will be able to:
30 minutes of Private Pesticide Category 1 (grain and cereal crops) recertification
0.5 CCA Continuing Education Units (Integrated Pest Management)
Live drone demonstration: fungicide/cover crop application methods
Dinner and overview of Dailey Farm’s/OSU Extension’s on-farm research plat: Soybean Seeding Rates

*See the flyer below for more information.

You can register for the Agronomy Series and the On-Farm Research Tour online by using the links above or  by calling the Brown County Extension Office at 937-378-6716 or by emailing Amanda Perkins at perkins.715@osu.edu.



4-H Updates 4.28.22

Check out all the 4-H things coming up!

As we head further into spring and summer is closing in there are LOTS of opportunities for you and some are right around the corner! We wanted to send out an update on upcoming events; this list isn’t everything. Read carefully and don’t miss out! As always, keep an eye out for project letters which will be emailed out on a rolling basis starting very soon. Letters all get posted on our website also. We try really hard to keep the calendar up to date (http://go.osu.edu/brown4hcalendar)  and this also loads into our 4-H Now App. If you see something missing, feel free to reach out!

  • Virtual Quality Assurance – Saturday, April 30th at 10 am. Pre-Register and see QA information on the website here: http://go.osu.edu/brownqa
  • Camp Open House – Sunday, May 1st – Noon-4 pm at Canter’s Cave 4-H Camp, Jackson, OH. Bring out the whole family to check out camp!
  • Workforce Skills Contest Registration Due – May 5th; Contest Date- May 11th
    • Open to all project age members. Youth will compete in age divisions by selecting from our list of jobs, preparing a cover letter, resume, and completing an interview. Full details are on the website http://go.osu.edu/workforceskills
    • Thank you to our generous Sponsors – Bane Welker Equipment, Howsers One Stop Shop, Triple S Boer Goats, and the Brown County 4-H Committee. We will be giving out prizes per age division. 1st Place – $100; 2nd Place – $75; 3rd Place – $50.
  • Quality Assurance – In-person – May 10th, 6 pm – Rhonemus Hall
  • Camp – 4-H Camp is a great opportunity for all youth. Campers stay in cabins, get a chance to hike, make friends, go to campfires and SO MUCH MORE! There is also a camp for everyone. Not all registration links are posted but as they are they can be found at http://brown.osu.edu/4hcamp
    • Camp Scholarships – there are multiple camp scholarships available for youth attending Beginner, Jr. High, Teen, STEM, and Junior Shooting Sports Camps. The deadline to apply is May 11th. Scholarship can be found on the camp link above below the table with camp dates.
    • Beginner Camp – Registration deadline – May 16th
    • Junior High Camp, Special Needs Camp – Registration Deadline – June 1st
    • Jr. and Senior Shooting Sports Registration deadline – June 15th
    • Others will be posted as available
  • Workforce Skills Contest Interview & Awards – May 11th; Rhonemus Hall
  • Shooting Sports Safety Meeting – May 12th, 6:30 pm – Rhonemus Hall – Required for all youth taking a shooting sports project to be eligible for range activities
  • Junior Leaders May 17th– open to all 4-Hers who are 13+ at the time of the meeting. Junior Leaders is designed to be educational, service, and social-based. Teens who are involved help with various activities throughout the year and plan activities. Meetings are at 5:30 pm at the Extension Office. Email me at clary.42@osu.edu to be added to the email list. New members are always welcome!
  • June 1st – Major Deadline Day (more details will be sent with project letters on all the deadlines)
    • Horse and Dog paperwork due; State Fair QA Deadline; Jr. High Camp Registrations Due; Beef Breeding, Sheep, Goat, Swine Ownership Deadline

We hope you will all consider taking advantage of the many opportunities available!

Please remember that failure to read and understand provided information is not an acceptable reason for unmet requirements or missed deadlines. If you do not understand, please ask clarifying questions. We are happy to help clarify information and help you complete the process in advance of deadlines.

Monarch Way Station Spring Makeover

The Brown County Master Gardeners spent some time this week giving the Monarch Way Station a makeover for the spring. During the makeover the gardeners weeded, mulched and trimmed some of the plants that are in the way station. Enjoy the way station on the Brown County Fairgrounds on the left side of the Extension Office. Below you will see some of the master gardeners with the way station in the background.


Are you looking for something fun to do this summer? 4-H Camp has something fun for everyone! At camp you will get to stay in a cabin, go swimming, fishing, hiking, dancing and so much more! The best part is you don’t have to be enrolled in 4-H to go to 4-H camp. Registration is now open for both Beginner and Jr. High Camps. Registration for Beginner Camp closes May 16, 2022. Registration for Jr. High Camp closes June 1, 2022. Camp Scholarships are available to help offset the cost of camp and are due MAY 11, 2022. In addition to the Beginner and Jr. High Camps there are also specialty camps. These specialty camps include Special Needs, Jr. Shooting Sports, Sr. Shooting Sports, STEM, and Teen Camp! There is something out there for everyone!  More details and registration links and deadlines can be found here.