A Novel Approach for Cover Crop Termination - Soil Savvy

Roller crimping of cover crops offers a novel approach to cover crop termination.

It provides multiple benefits ranging from weed suppression and soil erosion control to nutrient retention and water conservation. It offers a sustainable way to terminate cover crops without herbicides or tillage and supports the long-term health and productivity of farming systems.

It involves using a cylindrical device with blunt blades to flatten and crimp the stems of the crops impairing the vascular system and killing them. The cover crops form a thick mulch layer on the soil surface while retaining the roots anchored to soils.

Since the stems are not cut and chopped, or incorporated into the soils, the decomposition rate of the mulch layer slows down. This maximizes the benefits obtained from the residue mulch including weed suppression and moisture retention.

This system requires careful planning and management to obtain high efficacy and benefits especially given the short growing seasons in the Canadian Prairies. Ideally, cover crops get crimped when they reach the flowering or reproductive stage, as this is when they are least likely to regrow or produce viable seeds following crimping.

Operators need to use the roller crimper in the same direction as seeding to avoid residue wrapping around planter components. The suitability of different cover crops to roller crimping and the benefits can also be variable. Cereal rye, triticale, and hairy vetch are among the most suitable species for this technique as they can produce enough biomass to suppress weeds and are sensitive to crimping at their flowering or reproductive stage.

If you try this, adjust the seeding rate to achieve adequate ground coverage without risk of lodging. Make sure the roller crimper has sufficient weight and blade length to crimp the cover crop stems effectively. It should also have a flexible linkage system to adapt to the field contours or uneven terrain. Check out our first presentation on this project that explores the feasibility and benefits of this technique in southern Alberta irrigated farmlands.