Minnesota
Representative warm-season temperature is 18.5°C, inside the 16–24°C optimum. Annual rainfall is 704 mm, inside the 500–800 mm optimum rainfall band.
Compared on representative regional temperature and rainfall.
Commercial crop requirements
Growing Flax: climate, soil and water requirements
Flax has an optimum temperature range of 16–24°C within an absolute 5–30°C envelope.
Its profile calls for 400 mm of seasonal water and an optimum soil pH of 6–6.5.
How to read the figures
Profile figures come from the source cited at the foot of this page. Regional figures are representative reference values, not coordinate-level measurements.
Climate envelope
Use the optimum band for screening normal crop development and the absolute range as an outer tolerance boundary. Accumulated heat still depends on the local planting window and daily temperatures.
| Requirement | Profile value |
|---|---|
| Optimum temperature | 16–24°C |
| Absolute temperature range | 5–30°C |
| Heat to maturity | 1,675 growing degree days above a 5°C base |
| Photoperiod | Long-day response; 14-hour critical daylength |
| Vernalisation | Not required |
Soil and pH
| Requirement | Profile value |
|---|---|
| Optimum pH | 6–6.5 |
| Tolerated pH range | 5.5–7 |
| Waterlogging tolerance | Intolerant |
An intolerant rating means drainage is a screening constraint. Check infiltration, perched-water risk, field outlets and the duration of saturation before committing land.
Water
| Requirement | Profile value |
|---|---|
| Seasonal water requirement | 400 mm |
| Optimum rainfall band | 500–800 mm |
| Absolute rainfall range | 250–1,300 mm |
Irrigation becomes necessary when effective in-season rainfall is below the 400 mm seasonal requirement. Convert that gap into a field schedule only after accounting for soil water storage, application efficiency and local rainfall timing.
Nitrogen demand
The profile assigns Flax nitrogen-demand category 3, which translates to moderate demand. It is a relative category, not a fertiliser rate.
Set the field program from soil and tissue evidence, expected removals, prior-crop effects and local nutrient rules.
Crop-level reference profile
| Requirement | Profile value |
|---|---|
| Average yield | 0.83 t/ha reference average |
| Growing period | About 110 days to maturity, derived from 1,675 growing degree days above 5°C at a 20°C mean season temperature. Modelled from the crop profile. |
Where it grows well
These examples pass a stated temperature or rainfall comparison using representative regional values. Regional screening, not parcel-level.
North Dakota
Representative warm-season temperature is 17.3°C, inside the 16–24°C optimum. Annual rainfall is 506 mm, inside the 500–800 mm optimum rainfall band.
Compared on representative regional temperature and rainfall.
Iowa
Representative warm-season temperature is 21°C, inside the 16–24°C optimum. Annual rainfall is 771 mm, inside the 500–800 mm optimum rainfall band.
Compared on representative regional temperature and rainfall.
Regional guides
Research basis
These papers support the qualitative interpretation of the crop profile. No paper-derived figure is used on this page; the named crop and region fields remain the only sources of displayed agronomic numbers.
- Genome-wide analysis of drought induced gene expression changes in flax
Flax responds to water deficit in roots and shoots, supporting field water status as a crop-development constraint.
Taking this to a field decision
This profile cannot set planting depth, row spacing, seeding rate, cultivar choice, fertiliser rate, harvest timing, irrigation schedule or drainage design. Those decisions depend on cultivar, local practice and field conditions.
Use a coordinate-level audit, local field evidence and commercial terms before a land or lending decision.
Crop profile source
Wikidata & Literature (Field Crops Research, 1989, Agronomic importance of adverse soil conditions).