Glyphosate Alternatives for Cover Crop Termination

Many no-till systems rely on glyphosate to terminate cover crops before drilling. Uncertainty over glyphosate’s regulatory future and demand from organic systems is driving investigation into mechanical alternatives.

The Challenge

  • Glyphosate is the standard tool for cover crop termination in no-till and min-till systems
  • Regulatory uncertainty in EU (as of 2018: ongoing re-approval debates)
  • Organic farmers cannot use glyphosate — must reduce tillage reliance without it
  • Goal: terminate cover crop to create weed-suppressing mulch, then direct drill through

[Source: dd-issue-01, 2026-04-11]

Roller Crimper

Mechanism

  • Rolls over cover crop with ridged drum, flattening and bruising stems of most plant species
  • Creates a lying mulch of killed crop
  • Weed suppression: the mat of biomass suppresses weed germination
  • Direct drill through the crimped mat — no tillage; minimal compaction

Origin

  • Rodale Institute concept (USA); also used in Japan
  • andrew-woof (Weston Farm, Oxfordshire, 500 acres organic) — first UK trialler reported in Direct Driller

Results (UK, 2018)

  • “Results have been few and mixed” — technique unproven at scale in UK at time of writing
  • More established in US and organic systems

Research (Innovative Farmers / Anglia Farmers Field Lab)

  • Field lab running through Anglia Farmers and the Innovative Farmers network
  • Combining organic farmers seeking to reduce ploughing with conventional farmers seeking glyphosate independence
  • Partners: ADAS, Duchy College, Centre for Agroecology Water & Resilience (Coventry University), Food Security & Land Research Alliance, IBERS, Harper Adams University, Rothamsted Research, University of Bristol
  • Backed by: LEAF, Innovation for Agriculture, Organic Research Centre, Soil Association
  • Funded by: Duchy Future Farming Programme / Prince of Wales’s Charitable Foundation
  • Supported by: Waitrose

[Source: dd-issue-01, 2026-04-11]

Other Approaches Under Investigation

  • Mechanical flailing/mowing
  • Rolling without crimping
  • Shallow cultivation (min-till compromise — partial soil disturbance)
  • Overwintering covers that winter-kill naturally (mustard, phacelia, some brassicas)

Standard Glyphosate Method (for reference)

  • Spray cover crop on the same day as drilling (or just before)
  • Moisture translocation stops ~24 hours after spraying
  • Critical: no rain between spraying and drilling — otherwise cover becomes mulch that prevents soil from drying
  • Blackgrass management: spray by end of January if blackgrass present
  • Organic farmers / anti-glyphosate: graze cover lightly (no overgrazing) instead

[Source: dd-issue-01, 2026-04-11]

Detailed Crimper Roller Technique (from TCS/Arvalis Research)

For a comprehensive treatment of roller crimper design, conditions for effective use, species susceptibility, and combined rolling+herbicide trials, see Roller Crimper.

Key additions from Issue 2 (Matthieu Archambeaud, TCS Magazine No. 64, 2011):

Effective Conditions

  • Most effective on well-developed vegetation — especially after flowering when plant reserves redirect to reproduction
  • Frost dramatically improves effectiveness — rolling during frost recommended for hardy species
  • Large-diameter crimpers more consistent than flat rollers; helical blade arrangement better than straight-mounted blades (reduces vibration, more even pressure)

Combined Rolling + Herbicide (Arvalis/Labreuche, 2009–2011)

  • Rolling before glyphosate saves 50% herbicide on volunteer rapeseed (360 g/ha + rolling = same as 720 g/ha without rolling)
  • Spray within 2 hours of rolling for maximum effect — injured plant tissue better absorbs herbicide
  • Effect diminished after 24 hours; negligible after 15 days
  • Broadleaf weed destruction improved 40%; cruciferous 70–99%; crimson clover 95%

Species Susceptibility

  • Easy to kill: mustard (green), crimson clover, field bean, rye (at flowering with blade crimper)
  • Resistant: perennial species (red clover, alfalfa), turnip, hardened rapeseed

[Source: dd-issue-02, 2026-04-11]

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