Bio-organic fertiliser: how to use it so it isn’t a placebo
Look at composting, salt and the C:N, not the cartoon on the bag.
- The bag says microbes; the soil is still hard, salty, thin.
- One season later the house is unchanged.
- Bag fertiliser is this season’s nutrient; an inoculant does not replace N, P or K.
- Sterilising kills a whole community, including the useful ones. Rebuild after.
- Don’t mix with a sterilant; don’t skip soil repair and only pour microbes.
- Rate: Follow the registered label. Don’t double it as a miracle
- Name what you see before you feed.
- If leaves, roots and the surface disagree, stop.
What you see in the field
The bag says microbes; the soil is still hard, salty, thin. One season later the house is unchanged.Rub a handful next to a darker neighbour that still forms crumbs. Pale dusty soil that leaks after rain matches this page. Yellow leaves are extra — first ask whether the soil still has body.
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 “Bag fertiliser”
Bag fertiliser is this season’s nutrient; an inoculant does not replace N, P or K.
Looks like “Soil sterilising”
Sterilising kills a whole community, including the useful ones. Rebuild after.
Do this / don’t do that
- 1Compare the worst plants with a neighbour ridge. Photograph whole plant, close-up and soil surface before you add fertiliser.
- 2Match roots, leaves and the soil surface to this guide. If they do not line up, do not copy a bag count.
- 3Use the rate range on this page only as a range. Confirm with a local station and the product label.
Don’t do this first
- Don’t mix with a sterilant; don’t skip soil repair and only pour microbes.
Rate range
Rate
Follow the registered label
Don’t double it as a miracle.
What goes with it
Organic material + the right moisture
This is the condition that makes it work.
These are ranges. Confirm with your local extension station and the product label.
How soon after a spray or a feed it showed
A 1–3 day burst looks more like spray injury / fertiliser burn.
When you see The bag says microbes; the soil is still hard, test. Write the field and the date on the bag.
Lesson video
2026-03-09 · 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