Zinc shortage often hides behind high phosphorus
The P bag can starve zinc.
- Nitrogen shortage yellows old leaves evenly; zinc shortage hits the growing point first.
- Spray injury has a spray time; zinc shortage creeps.
- Don’t raise P when zinc is short; don’t double foliar zinc.
- Foliar zinc: Follow the pack. Commonly 0.1–0.2%. A small patch first, not at noon
- Name what you see before you feed.
- If leaves, roots and the surface disagree, stop.
- P and zinc queue at one door.
- A crowd of P blocks zinc.
What you see in the field
Maize white-bud, short internodes; the sheet shows high P and low zinc.First the leaf position: new or old, even yellow or between the veins. If that does not match, do not fertilise yet. Pull one plant and read whether the roots are white, brown or foul.
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 “Nitrogen shortage”
Nitrogen shortage yellows old leaves evenly; zinc shortage hits the growing point first.
Looks like “Spray injury”
Spray injury has a spray time; zinc shortage creeps.
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 raise P when zinc is short; don’t double foliar zinc.
Rate range
Foliar zinc
Follow the pack. Commonly 0.1–0.2%
A small patch first, not at noon.
Soil zinc
Once in several years, follow a soil test
Don’t dump it every year.
These are ranges. Confirm with your local extension station and the product label.
When you see Maize white-bud, test. Take soil from the bad patch and from a greener neighbour, separately.
Lesson video
2026-03-13 · 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