The challenging 2025 planting season may result in a challenging 2025 harvest season. Producers will have several factors to consider before the choppers hit the fields and may need some added patience to ensure harvesting the highest quality forage possible. This year there is a possibility that nitrates could be an issue in some harvested forages. Elevated plant nitrate levels are the result of the plant’s inability to convert soil nitrate into plant proteins due to growth being slowed by environmental conditions. Soil nitrates are taken up through the roots and once in the plant are converted to nitrite, then ammonia, then amino acids, and finally to plant proteins. In our situation, we have adequate soil moisture for the plant to continue to take up nitrates, but the cool temperatures are slowing growth preventing their full conversion.
First, target harvest based on plant moisture
A producer’s focus should first be on targeting harvest of each field based on plant moisture. In last week’s edition of the CORN Newsletter, Jason Hartschuh, OSU Extension Dairy Specialist, provided several recommendations for estimation of standing moisture content. He reminds everyone that the ideal plant moisture at harvest should be between 62 and 70%. Kernal milk line can be used to estimate total plant moisture content. He states that when the kernel is at 1/3 milk line, the silage moisture is generally 68 to 72% and by 2/3 it is at 62 to 68% moisture.
If cool temperatures persist up to harvest, it would be advisable to add nitrate testing to your forage analysis. Since we rely on the conversion of nitrates in the plant during growth, nitrate levels will not be reduced in harvested forages. Increasing chopper harvest height can reduce concentrations as nitrates typically accumulate in the lower portion of the plant. However, fermentation can reduce the concentration of nitrates in silage from 10 to 65%. Samples should be less than 1,000 ppm Nitrate Nitrogen on a dry matter basis. Those feeds that are above the limit can be diluted with low Nitrate silage to achieve the desired levels.
I should also remind you that fermentation of high nitrate corn can lead to safety concerns from gases produced during the process. Nitrogen Dioxide and Carbon Dioxide can reach deadly levels just 24 hrs. after harvest. This is most critical for those utilizing upright silos. As this year’s harvest may be spread out, you will want to be very cautious entering a silo between harvested fields. At a minimum, you should run the blower for 1 hour prior to entry. I would highly recommend you purchase a gas detector to measure concentrations before entry. You can be quickly overcome by the gases and rescuers are in danger as well.
Upcoming: Wayne County Fair, ruminant field day, Ag Lenders Seminar
I hope to see everyone at the Wayne County Fair this week. It looks as though the weather is going to be ideal for animals, showmen, and spectators alike. We have a couple programs coming up. On October 18th, we will be hosting a small ruminant field day at the OSU Small Ruminant Research Center on Fredericksburg Rd. The program will run from 9:00 AM to 2:00 PM. We will have a mix of presentations and demonstrations covering: care of newborns, dystocia management, estrus synchronization, estimating forage yield and quality, and developing a flock nutrition program. The program costs $10 per person and lunch will be provided. We ask that you register by October 16th. On October 21st we will be hosting our annual Ag Lenders Seminar at Secrest Arboretum Welcome Center. This year we will discuss: The impacts of the “Big Beautiful Bill” on Ag, tariffs on US trade, a new building construction outlook, and a 2026 grain outlook. Finally, on October 21st we have the first session of Small Farm Business College. The program will cover developing a business plan and understanding legal concerns for small farm owners. The program will be held one night each week for four weeks. As always, I hope that you have a safe and prosperous harvest season. If you have any questions or would like to register for one of our programs, please contact me at 330-264-8722 or yost.77@osu.edu
John Yost is an extension educator IV, Agriculture and Natural Resources, at OSU Extension-Wayne County.
This article was previously published in The Daily Record.