Farmland · soils

What to grow when the usual rotation drowns

Heavy clay, lowland peat and silty floodplain soils are the UK types that stay wet longest in autumn and winter. When winter wheat is written off, the investor question is paludiculture, flood-tolerant food, or a rescue cover — not another year of the same crop. Identify on the map infers a likely family from ALC, flood zone and geography; it is not a Cranfield texture test.

There is no free nationwide API of topsoil texture at a coordinate (NATMAP / Soilscapes is licensed). This briefing plus Identify is a screen. Spade a pit, and if the holding is coastal or Fen-edge, pay for salinity (EC) before you change the rotation.

How those soils behave under water

Heavy clay

Common across the Midlands and South East (London Clay, Weald, clay vales). Particles are tiny and compact. Heavy rain fills the pores, drives out oxygen, and the field can stay anaerobic for weeks after the rain stops. Machinery smears the surface. Winter wheat and oilseed rape are the usual cash crops — and the first to fail in a wet autumn.

Lowland peat and Fen soils

East Anglia and the Fens, Somerset Levels, Humberhead Levels. Often ALC Grade 1 or 2 — among the most productive soils in the UK — sitting on a high water table. Pumping and deep drains keep wheat and beet going, but they also shrink the peat, drop field level and release carbon. Identify treats a point inside those geographies as paludiculture-first when it is also wet.

Silty and alluvial soils

River valleys and washlands. Fertile, then a hard cap as the silt dries, and rapid flooding when the river comes out. If Identify shows Flood Zone 2 or 3 and the point is not Fen peat, this is the family we attach.

Other soils (so you do not over-apply wetland crops)

Chalk (Downs, Chilterns, Wolds) and sands (Breckland) drain. Flood-tolerant horticulture is the wrong default there unless a valley floor actually inundates. Upland peat and gleys (ALC 4–5, Wales, Pennines) stay wet from rain and slope — restoration and grazing, not Fen-style typha as a cash swap. Urban ALC is not a rotation question.

Instead of the usual cash crop

1. Paludiculture (farming the wet)

Rather than fighting the water, grow on saturated or rewetted peat. Defra’s Sustainable Farming Incentive has included paludiculture and rewetting options because they keep an agricultural output while slowing peat loss. The offer changes — read the current SFI list before you underwrite income.

• Typha (reedmace / cattail) — insulation, bio-plastics, biomass fuel; stands in water.
• Sphagnum moss — peat-free horticultural compost on deliberately flooded peat.
• Reed canary grass — perennial biomass pellets; withstands total waterlogging.
• Willow (Salix) coppice — bioenergy, weaving, and a flood-roughness belt on wet headlands and washlands.

2. Flood-tolerant food, if it dries by late spring

Use these when the flood is seasonal, not a permanent wetland.

• Celery and celeriac — wetland ancestry; root systems that take saturation.
• Watercress — high-value salad in moving, shallow, clean water. Stagnant floodwater is not a cress bed.
• Savoy cabbage, kale, chard — hardy leaf that outlasts carrots and onions in cold wet.

3. Rescue covers after a write-off

If the cereal is gone, do not leave the field bare. Deep-rooting covers rebuild structure and catch nutrient that would otherwise leave in the next flush.

• Oil radish and vetch — taproots through smeared clay; natural drainage channels for spring.
• Spring rye and mustard — fast annuals on damp ground to hold nitrogen.

Saltwater risk

Coastal Fens, the Wash, Essex and North Kent marshes, and parts of the Somerset coast can take brackish or seawater in a surge. Salt stays in the profile for years and kills most of the swaps above. Winter wheat is one of the few traditional crops that sometimes persists. Identify flags “test salinity” inside those boxes — it cannot measure EC from a map.

Fresh inland floodplain (Trent, Severn, Thames washland away from the tide): paludiculture and flood-tolerant food are the live options. Coastal / Fen-edge: pay for a salinity test before you drop wheat for typha or celery.

Weather this week (growth vs no growth)

Identify pulls a 14-day Open-Meteo window (7 days back, 7 ahead): rain, frost, evapotranspiration and topsoil moisture. Combined with the soil family it calls a growing window — frost, waterlogged clay/peat, or drought on chalk and sand. A dry week in the air does not dry Fen peat. This is a model forecast, not a Met Office farm warning and not agronomy advice.

The same panel names the appointed water company (EA Water Resource Zones — Anglian, Thames, Severn Trent and the rest; Scottish Water / NI Water by nation) and the electricity distribution network operator (the wires company). Who sells you units — Octopus, British Gas, EDF — is a retail contract. There is no public map of that to a field.

On this map

Identify → Summary and Dossier show the inferred family, the wet regime (peat / clay / freshwater floodplain / salt), and the crop packs. Buy carries the same notes next to ALC. That is still a screen: ALC is capability, flood zone is planning, geography is a box. MAGIC and a soil pit remain the evidence.

Example — Fen peat near Holbeach · Example — Midlands clay near Kettering · Farmland prices · MAGIC · UK Soil Observatory