Multi-species grass/herb leys as a tool for building soil organic matter, drought resilience, and animal health. Based on Ian Wilkinson’s article for Cotswold Seeds (Direct Driller Issue 3).
The Case for Herbal Leys
Ian Wilkinson (Cotswold Seeds) argues that arable rotations have become too narrow and that reintroducing grass — particularly diverse herbal leys — delivers:
- Soil organic matter building — deep-rooting species add carbon at depth
- Drought resilience — deep roots access moisture conventional crops cannot reach
- Animal health benefits — bioactive compounds in certain species reduce worm burden in livestock
- Break crop benefits — disrupts pest and disease cycles more effectively than a single-species break
[Source: dd-issue-03, 2026-04-11]
Key Results
Rob Richmond — SOM Transformation
- Soil organic matter increased from 2–4% to 8–9% in 12 years using herbal leys
- One of the most dramatic SOM increases documented in UK farming
Charles Hunter-Smart — Bradwell Grove Estate (2,500 acres)
- Uses sainfoin and birdsfoot trefoil in herbal leys
- No ewes wormed for 2 years — the condensed tannins in sainfoin and birdsfoot trefoil act as natural anthelmintics
- Significant veterinary cost saving alongside soil benefits
[Source: dd-issue-03, 2026-04-11]
Best Species for Drought Resilience
The 2018 drought highlighted which species within herbal leys performed best under extended dry conditions:
| Species | Drought performance |
|---|---|
| Chicory | Excellent — deep taproot accesses subsoil moisture |
| Sainfoin | Excellent — deep-rooting legume; also anthelmintic |
| Birdsfoot trefoil | Excellent — deep-rooting; tannin content reduces worm burden |
[Source: dd-issue-03, 2026-04-11]
Optimal Ley Duration
4-year ley recommended for optimal soil-building results. Shorter leys deliver some benefit but do not allow full root system development or maximum SOM accumulation.
[Source: dd-issue-03, 2026-04-11]
Integration with No-Till
Herbal leys fit within no-till rotations as a restorative phase:
- Drill ley mix with a direct drill into cereal stubble
- Graze with livestock (see Livestock Integration in No-Till Systems)
- Terminate after 3–4 years using Glyphosate Alternatives for Cover Crop Termination or grazing + frost
- Drill cash crop directly into terminated ley residue
The deep root channels left by chicory and sainfoin improve water infiltration and drainage for subsequent arable crops.
[Source: dd-issue-03, 2026-04-11]
Related Pages
- Soil Carbon and Organic Matter — SOM building methods
- Cover Crops — Shorter-term green cover approaches
- Livestock Integration in No-Till Systems — Grazing herbal leys
- Soil Farmers of the Year 2018 — Angus Gowthorpe grazing cover crops with cattle
- Conservation Agriculture — Core Principles — Diverse rotations as CA pillar