Considerations for Terminating Cereal Rye
We have talked about the benefits of cereal rye, what to look for as it greens up, and how to graze it. Now it is the end of the road for the cereal rye cover crop. Here are some things to consider when making your termination plans:
One double edged sword of cereal rye is its use of moisture. When springs have excessive moisture, cereal rye can be like a straw stuck in the soil to pull up and use that extra moisture. However, in ground that does not have moisture to spare, that moisture used by cereal rye can be a negative. A good way to manage this part of your termination decision is to know the soil types of fields and how they hold moisture. Using a soil moisture meter can also be a way to determine when to terminate your cereal rye.
We receive a lot of questions about the concern of the allelopathic effect of cereal rye on subsequent crops. While this can be evident in some cases, we have also seen that this is commonly a nutrient tie-up situation. Cereal rye is very fast growing in the spring, and with that comes a lot of nutrients being taken up into the plant, including nitrogen.
The timing of cereal rye termination decides how quickly those nutrients release back to the soil. Cereal rye terminated early, while still vegetaitve, will break down quickly and release nutrients that it accumulated. In some cases, this quick release can act as a starter fertilizer for the cash crop. On the other hand, cereal rye terminated late will take longer to break down. This is due to a higher carbon content of the plant. This delayed release of nutrients, nitrogen specifically, can cause issues with early growth of cash crops like corn.
Having equipment properly set up to handle cereal rye residue is important. In a no-till situation, having proper residue clearing equipment on the planter will help ensure uniform planting depth. Another equipment option that is used to terminate cereal rye is a roller crimper. This process is done when the cereal rye is at anthesis (when the seed head begins shedding pollen) and terminates the rye by snapping the stem and crimping the plant to let moisture out. This can be an effective weed control method as the cereal rye lays down and provides a protective barrier that can also keep soil moisture in to battle drought. Having your planter set up with adequate down pressure to plant into a rye mat is a key consideration.
What to Spray
If you are planning a chemical termination of your cereal rye, consult your local herbicide provider for specifics on what will work best on your ground. Below are the results of a 3 year study conducted in Missouri as a reference of what some common combinations are.
When to Spray
Just like we spoke about above, there are many factors that play into the timing of spraying. It is important to consider the moisture and nutrients the cereal rye will use before it is terminated. Below is one example of a study done on the termination date of cereal rye. Keep in mind this is just one study in one year, so things will vary from year to year and farm to farm.
In the end, the overall benefits of cereal rye make it a great cover crop option. Having the living root in the ground over the winter benefits soil biology and is a strong erosion control method. The quick growing fibrous root system is also working for you this spring by building soil structure and stimulating soil biology to prime your soil for your cash crops.
Watch for upcoming information on when to harvest your cereal rye as forage!
Gailans, Stefen. "Cereal Rye Cover Crop Termination Date Before Corn." Practical Farmers of Iowa,
3 May 2019.
"Terminating a Cereal Rye Cover Crop – Things to Consider." University of Nebraska Lincoln,
13 Apr. 2017.