Essential Tips for Terminating Cover Crops in Spring

By Blake Jackson

As spring arrives in Missouri, soybean growers face a crucial decision: when and how to terminate cover crops. When managed well, cover crops can improve soil health, suppress weeds, and conserve moisture. However, poor termination can lead to issues at planting time. Here’s a guide to help Missouri soybean farmers navigate this critical step.

Timing Is Key
For lower biomass cover crops, the general rule is to terminate 10 to 14 days before planting. This gives the biomass time to decompose, preventing the formation of wet, matted residue and reducing the risk of pest or disease problems. Early termination also helps avoid creating a "green bridge" that can transfer pests or diseases between crops.

Planting Green Considerations
More farmers are experimenting with planting green, where cover crops are terminated after planting. While this method can be effective, farmers need to ensure their equipment is prepared for heavy residue and monitor soil moisture closely to prevent creating cool, damp seedbeds. It’s recommended to start small and expand gradually as you gain experience.

Know Your Cover Crop
Different cover crops respond differently in spring. For instance, cereal rye is popular for its weed suppression properties, while legumes like crimson clover improve soil fertility by fixing nitrogen. Brassicas like radishes and turnips may winter-kill but should be monitored to confirm survival.

Termination Methods
Most Missouri growers use herbicides like glyphosate, which works well when cover crops are actively growing. Roller crimpers are effective on mature cereal rye, while mowing or light tillage may be used when other methods are not suitable.

Weather and Equipment Check
Spring weather can impact termination. Cool temperatures can reduce herbicide effectiveness, while wet soil may delay field entry. In dry conditions, cover crops may absorb moisture needed for the main crop. Be sure to check the forecast and ensure your planter is set up properly to handle residue.

Align with Herbicide Program
Your herbicide strategy should complement your termination plan. Avoid tank-mixing glyphosate with products that may reduce its effectiveness, and wait until the cover crop is fully terminated before applying residual herbicides. 

By following these tips, Missouri soybean farmers can optimize their cover crop termination strategy, ensuring better soil health and a successful planting season.

Photo Credit: gettyimages-eugenesergeev