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Black-soil organic matter drops fast — how to keep it

Stop mining the warehouse.

Thin organic matter
Speed
  1. The black layer is thinning.
  2. Nitrogen still buys yield; the meat is leaving.
  3. A this-season shortage can be fed; degradation is the layer getting thinner.
  4. The Northeast has salt patches, but decline is mainly thin and poor.
  5. Don’t treat thinning black soil as a nitrogen pit; don’t leave slopes bare in winter-spring.
  6. Straw: Return it if you can. See the nitrogen top-up guide. Leaving the field is throwing meat away
  7. Name what you see before you feed.
  8. If leaves, roots and the surface disagree, stop.

What you see in the field

The black layer is thinning. Nitrogen still buys yield; the meat is leaving.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.

A sketch. Do not fertilise from the picture alone.

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 “Ordinary shortage”

    A this-season shortage can be fed; degradation is the layer getting thinner.

  • Looks like “A salt-alkali patch”

    The Northeast has salt patches, but decline is mainly thin and poor.

Do this / don’t do that

  1. 1The black layer is thinning. Nitrogen still buys yield; the meat is leaving. Compare the worst plants with a neighbour ridge before you add a bag, or the next step will chase the wrong thing.
  2. 2Return straw, cover slopes, less bare ground in the windy window. Organic matter as meat. Subsoil alternate years, don’t invert raw subsoil yearly.
  3. 3Don’t treat thinning black soil as a nitrogen pit. 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 thinning black soil as a nitrogen pit; don’t leave slopes bare in winter-spring.

Rate range

Straw

Return it if you can. See the nitrogen top-up guide

Leaving the field is throwing meat away.

Rotate deep loosening

Every other year

Protect the tilth.

These are ranges. Confirm with your local extension station and the product label.

Organic matter

The meat in the soil

The trend down matters more than one absolute.

Black-layer thickness

How much capital is left

Getting thinner: protect it.

When you see The black layer is thinning. Nitrogen still buys yield; the meat is leaving, test. Walk an S and mix — one hole is not the field.

Lesson video

2026-03-24 · 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