Conservation Agriculture — Core Principles

The foundational framework underpinning direct drilling, no-till, and zero-till systems. Adopted by the UN FAO in their publication Save and Grow.

The Three Linked Principles (FAO / Cornell)

  1. Minimum mechanical soil disturbance — seed directly into untilled soil; no inversion of the soil profile
  2. Permanent organic soil cover — maintain crop residues, cover crops, or mulch on the surface year-round
  3. Diversification of species — crop rotations and/or associations; annual and perennial; may include trees, shrubs, cover crops

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

US National Soil Resources Shorthand

  • Disturb the soil as little as possible
  • Keep the surface covered throughout the year
  • Have plants growing all the time

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

Terminology

Term Meaning
Zero-till No cultivations whatsoever
No-till Fractionally softer — very occasional light surface pass if absolutely necessary
Min-till Reduced tillage; risks of “light-till creep” damaging soil structure
Conservation Agriculture (CA) Broader FAO term; the three-principle system
Direct drilling UK common usage; seeds sown directly into stubble/residue

Note: “No-Till can become ‘light-till’ which can then damage the natural soil structure which the system relies on.”

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

Quantified Benefits (Prof Amir Kassam, Reading University)

Compared to conventional tillage, CA can reduce:

Input Reduction
Fertiliser 30–50%
Water 20–30%
Fuel 50–70%
Pesticide / herbicide 20%

Practical example — Tony Reynolds, Thurlby Grange Farm, Lincs:

  • Crop establishment: £266/ha (conventional) → £30/ha (zero-till)
  • Diesel: 96 litres/ha (2004–05) → 41 litres/ha (2013–14)

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

Global Adoption (as of 2018)

  • 117 million hectares globally under no-till / CA
  • Strong adoption in: Brazil (since 1971–72), Argentina, USA, Canada, Australia/NZ, Kazakhstan, China, parts of Africa
  • UK and Europe: adoption “very slow”

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

Associated Practices

  1. Use of green manures / cover crops to produce residue cover
  2. No burning of crop residues
  3. Integrated disease and pest management
  4. Controlled/limited traffic (CTF) over agricultural soils

Historical Context

  • 1943/1945: Edward Faulkner’s Plowman’s Folly — first published critique of the plough with no scientific justification found for inversion tillage
  • 1971–72: Brazil leads no-till revolution
  • 2004: Prof Kassam’s personal conclusion that “intensive tillage-based interventionist farming… is no longer fit to meet the agricultural and rural resource management needs of the 21st century”
  • 2018: 117m ha globally; Europe still lagging

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

Why Tillage Causes Harm

  • Severs capillary connections from water table to surface → soil dries out, plants struggle until structure recovers
  • Mouldboard smears and seals the ploughpan under wet conditions
  • Exposes sequestered carbon to oxidation → organic matter loss
  • Destroys soil aggregate structure, pores, and biological channels
  • Creates bare soil → worst erosion risk of any land condition
  • Lifts weed seeds to germination zone

[Source: dd-issue-01, 2026-04-11] (Faulkner, 1943)

Related Pages