Solarisation: it can knock pathogens back and also hurt roots and structure
A closed film in high sun is a tool with a back edge.
- Film on soil can knock pathogens; it also hurts structure and the living.
- Afterwards, harder, smellier soil is common.
- Chemical sterilising is another kit. Follow the label and the pre-harvest interval.
- Drying a paddy and closing a greenhouse are not the same job.
- Don’t treat solarisation as a forever vaccine; don’t disinfect, replant, disinfect as the whole plan.
- How long to close the house: Follow local rules. Commonly a few weeks. Longer is not always better
- Name what you see before you feed.
- If leaves, roots and the surface disagree, stop.
What you see in the field
Film on soil can knock pathogens; it also hurts structure and the living. Afterwards, harder, smellier soil is common.Patchy dead plants: look at the roots first — knots, brown rot, stained pipes — not the thin white roots of hunger. A rotated neighbour that still looks well is the contrast that counts.
Tap to enlarge. The caption says what to photograph. Missing field photos are marked as to-be-added.
Why it looks like this
The field looks like this because the root cannot take water or nutrients the usual way. Fix the soil condition first — drainage, salt, acidity, compaction or a salt of fertiliser — then a thin feed. Rates live in the range on this page; confirm with a local station and the label.
Easy to mix up
Looks like “Chemical sterilising”
Chemical sterilising is another kit. Follow the label and the pre-harvest interval.
Looks like “Drying the paddy”
Drying a paddy and closing a greenhouse are not the same job.
Do this / don’t do that
- 1Film on soil can knock pathogens; it also hurts structure and the living. Afterwards, harder, smellier soil is common.
- 2Solarise to spec. Nurse afterwards; don’t immediately replant the same crop dense. Rotation is safer.
- 3Don’t treat solarisation as a forever vaccine. Use the range on this page only as a range. Confirm with a local station and the product label.
Don’t do this first
- Don’t treat solarisation as a forever vaccine; don’t disinfect, replant, disinfect as the whole plan.
Rate range
How long to close the house
Follow local rules. Commonly a few weeks
Longer is not always better.
Feed the soil after the heat
Rotted manure
After sterilising, feed the soil.
These are ranges. Confirm with your local extension station and the product label.
When you see Film on soil can knock pathogens; it also hurts structure and the living. Afterwards, test. Take soil from the bad patch and from a greener neighbour, separately.
Lesson video
2026-03-11 · 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