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No-till is a crop-production practice that limits soil disturbance to the planting operation itself, so that crop residue stays on the soil surface year-round. In the USDA Natural Resources Conservation Service (NRCS) definition it is “limiting soil disturbance to manage the amount, orientation and distribution of crop and plant residue on the soil surface year around.” This page is for researchers, agronomy and field-trial staff, and students writing a methods section: it sets out the formal criteria, separates no-till from looser terms, and lists what a protocol should report.
Short answer
No-till means no full-width tillage between harvesting or terminating one cash crop and planting the next, at any depth. Only in-row soil disturbance during planting, plus a seed-row or furrow closing device, is allowed. It is a stricter category than “reduced tillage” or “conservation tillage”, and it is one of three components of the wider FAO concept of conservation agriculture.
Definition and scope
The reference text used here is NRCS Conservation Practice Standard 329, Residue and Tillage Management, No Till (the Indiana version dated October 2014, read 2026-11-08). NRCS publishes a state-specific version of the standard through each state’s Field Office Technical Guide, so numerical limits differ by state and year; check the current version for the state a study sits in.
- Scope: the standard applies to all cropland.
- Disturbance rule: only in-row tillage during planting and a seed-row or furrow closing device; no full-width tillage from harvest or termination of one cash crop to the next, regardless of depth.
- Residue rule: residues are uniformly distributed and not burned; moving residue away from the row area at planting is acceptable.
- Implements named: no-till and strip-till planters, certain drills and air seeders, and strip-type fertilizer or manure injectors.
- Synonyms the standard lists: no-till, quality no till, never-till, zero till, slot plant, zone till, strip till and direct seed.
How it is assessed in practice
NRCS uses the Soil Tillage Intensity Rating (STIR) to quantify disturbance. STIR counts all field operations in the crop interval, including fallow. The Indiana 2014 standard sets the maximum at no greater than 20; other state versions and years set different caps (some cite 15), so a STIR value should always be quoted with the state standard and year it was judged against.
The same standard lists the purposes the practice serves: reducing sheet, rill and wind erosion; reducing tillage-induced particulate emissions; maintaining or increasing soil quality and organic matter; reducing energy use; increasing plant-available moisture; and providing food and escape cover for wildlife. These are stated purposes of the practice, not measured outcomes for any given site.
No-till compared with conservation agriculture
The FAO describes conservation agriculture as “a farming system that promotes minimum soil disturbance” (FAO, Conservation Agriculture, read 2026-11-08). No-till on its own meets only the first of FAO’s three principles.
| Dimension | No-till (NRCS Standard 329) | Conservation agriculture (FAO) |
|---|---|---|
| Soil disturbance | No full-width tillage between cash crops; in-row disturbance at planting only | Minimum mechanical soil disturbance; seed and fertilizer placed directly |
| Soil cover | Residue kept on the surface and not burned; no cover threshold in the Indiana text | Permanent organic soil cover of at least 30 percent |
| Crop diversity | Not a criterion of the standard | Species diversification, at least three different crops |
| Unit of definition | A practice applied to cropland | A farming system of three combined principles |
Where it matters for research and field protocols
Because “no-till” is used loosely, two studies can claim it and differ in disturbance. A methods section or trial protocol that names the standard it follows removes that ambiguity. As an editorial checklist, a report of a no-till treatment should state:
- The planter, drill or injector used, and whether any in-row tool disturbed soil beyond the seed row.
- Whether any full-width tillage occurred between cash crops, including during fallow.
- The STIR value and the state standard and year used, if STIR was computed.
- What happened to residue: retained, redistributed, or moved from the row area; and whether it was burned.
- Whether cover or diversification criteria of conservation agriculture were also met, with the threshold cited.
- How the treatment was assigned and replicated; see blocking in experimental design and the experimental design entry.
For general reporting practice see writing the methods section so it can be reproduced and what is a research protocol. Wider field context is in what is agronomy and crop science and what is soil science.
Common misunderstandings
- “No-till” and “reduced tillage” are the same. They are not: under the NRCS standard any full-width tillage between cash crops, at any depth, disqualifies a field.
- No-till equals conservation agriculture. FAO’s system adds soil cover of at least 30 percent and at least three crop species.
- Strip-till is excluded. The standard names strip-till planters among approved implements and lists strip till among its synonyms, because disturbance stays in the row.
- One national number applies. STIR caps and other limits are set in state versions of the standard.
Frequently asked questions
What is no-till farming?
A system that limits soil disturbance to in-row planting and keeps crop residue on the surface year-round, as defined in NRCS Conservation Practice Standard 329.
Is strip-till the same as no-till?
The NRCS standard lists strip till as a name for the practice and approves strip-till planters, because soil disturbance is confined to the seed row.
Does no-till count as conservation agriculture?
Only partly. It covers the minimum-disturbance principle; FAO also requires permanent soil cover of at least 30 percent and diversification across at least three crops.
What is STIR?
The Soil Tillage Intensity Rating, which NRCS uses to score the disturbance of all field operations in the crop interval. The Indiana 2014 no-till standard sets a maximum of 20.
Sources
- USDA NRCS, Conservation Practice Standard 329, Residue and Tillage Management, No Till (Indiana, October 2014), Field Office Technical Guide: efotg.sc.egov.usda.gov. Read 2026-11-08.
- FAO, Conservation Agriculture: fao.org/conservation-agriculture. Read 2026-11-08.
