Waterlogging: wilt by day, wet soil, black roots
Drain first. Urea cannot enter a drowned root.
- Wilt by day, recover at night, standing water or a wet bottom, roots black and smelling.
- Wet soil and still wilted.
- Drought is dry soil. Waterlogging is wet soil and still wilted.
- Nitrogen yellows old leaves with white roots. Waterlogging blacks and smells the root.
- Don’t dump nitrogen the day after a flood.
- Drainage: Get air back to the roots as soon as you can. This is the first job
- Drain so the root can breathe.
- No nitrogen until new roots show.
- Wet soil and still wilted is drowning, not drought.
What you see in the field
Wilt by day, recover a little at night, standing water or a squelch underfoot, cool subsoil. Pull a plant: white roots or black and smelly. Wet soil that still wilts is not drought. Compare the worst patch with a neighbour that still stands. Paddy and dry land look different, but black roots are the shared sign. Read the root before the leaf.
Tap to enlarge. The caption says what to photograph. Missing field photos are marked as to-be-added.
Why it looks like this
Roots need air. Water fills the pores, oxygen cannot enter, tips die, and the top wilts by day. More irrigation keeps them drowning. Nitrogen cannot enter in low oxygen and is easily lost. Drain standing water and let the subsoil dry a little before you feed. Blocked ditches and cold, wet fields are common.
A sketch. Do not fertilise from the picture alone.Easy to mix up
Looks like “Drought wilt”
Drought is dry soil that recovers when you water through. Waterlogging is wet soil, worse after watering, black roots. Squeeze a handful.
Looks like “Nitrogen yellowing”
Nitrogen yellows old leaves while roots often stay white. Waterlogging blackens roots first; leaves can wilt and yellow together.
Do this / don’t do that
- 1Read wet versus dry soil, white versus black roots. Wilt on wet soil with black roots: drain first, do not irrigate again.
- 2The ditch must run. Send standing water away, let the subsoil dry a little, stop fertiliser, wait for new white roots.
- 3A thin feed only after new white roots. Urea cannot enter while roots are still black and will injure what is left.
Don’t do this first
- Do not irrigate wilt on wet soil as if it were drought.
- Do not pour urea on black roots.
- Do not block the drainage ditch.
Rate range
| Crop × texture | Texture | Rate | Note |
|---|---|---|---|
| Maize / vegetables | Any | Drain first. Thin foliar only after new roots | No nitrogen the day after a flood |
These are ranges. Confirm with your local extension station and the product label.
| Cell | Low | Mid | High |
|---|---|---|---|
| Organic matter / texture | Sand drains faster | — | Clay and a pan perch water |
One number example
Maize wilt by day, standing water, roots already black: open a ditch, stop fertiliser for a few days. Urea cannot enter while roots are black. Wait for new white roots after the water recedes.
One sample in the pond, one near the outlet. Wash one root.
Lesson video
2026-03-20 · Li Zeyu · For learning. Serious damage: local agronomist or a soil test.
For learning only. Fertiliser and pesticide decisions need a local agronomist and a soil test.
Not sure? Photograph the field to identify the problem