Row Crop Chemical Carryover – what you need to know when planting CRP

Chemical carryover caused by some new herbicides has become an increasingly frequent and potentially expensive problem for new CRP participants. If you used herbicide on the previous years’ crops, it may affect when you can plant your new CRP project. Some crop herbicides available on the market today have longer and longer carryover rates—sometimes 18 or even 24 months. This can adversely affect or prevent expensive CRP grasses and forbs from emerging if planted too soon.

If you are currently enrolled in, or looking to become enrolled in the CRP, chemical carryover can affect the seed mixes used for some continuous and general signup practices:

  • Native Grasses and Forbs
  • Pollinator Habitats
  • Cool Season Grasses and Legumes
  • Wetland Restorations
  • Wildlife Habitats

Generally, October 1st is the most common start date for your CRP contract, which gives you until September 30th of the following year to install the CRP practice. By the start of your CRP contract, you will have likely started harvesting your crops and will be anticipating planting your grasses.

Your CRP contract allows you to start planting in late fall following harvest or early the next spring, however depending on what chemicals you sprayed on your crops you may have to wait a full year before you can plant your CRP seed mix. Some of the new chemicals being used for corn and beans can stay in the soil for more than a year and you may have to wait until the following late November or even into the next year to allow the product to clear out of the soil.

Optimally, for planning purposes and as timing allows, we urge you to avoid using herbicides with long carry over times on crops prior to CRP enrollment. This will allow you to plant your CRP soon after you do your final crop harvest. If you did use a chemical with long carry over dates, there’s no reason to plant expensive CRP seed until the chemical is fully out of the soil.

Please let your USDA county office and FDCE know if chemical carryover will affect the ground you wish to enroll in CRP, as we will need to be aware of this as we plan the timing of your CRP practice.

The following products are examples that have residual carryover. Be aware of what you are applying and what the label directs outside of crop production usage.


  • Acruon
  • Outlook
  • Flexstar
  • Kyber


  • Matador