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Reading a soil-test sheet

The sheet is a measurement, not a prescription. Circle pH, organic matter and salt first.

Other
Speed
  1. Match the field name and the sample date first.
  2. Read in this order: pH → organic matter → salt → NPK → micronutrients.
  3. A missed decimal poisons the rate.
  4. The sheet is a measurement, not a prescription.
  5. Take it to the station rather than pasting another province’s table.
  6. A photo can only suspect. A sheet roughly quantifies. Yellow leaves have ten causes.
  7. Neighbour soil is not yours. Sand and clay, acid and alkali, can double the rate.
  8. The field name on the sheet must be the field you are standing in.
  9. Don’t fill every ‘low’ at the maximum.
  10. Don’t misread the unit.

What you see in the field

Match the field name, sampling depth and date before you read any number. Order: pH, organic matter, salt or EC, then NPK, then micronutrients. Misread the unit and the fertiliser goes the wrong way. Different soil:water ratios are not the same number. Put the sheet next to the roots, leaves and soil surface. The sheet is a measurement, not a prescription. Bag counts live in the field guide.

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 lab turns ions and organic matter into cells on a sheet. A cell is not a bag. pH gates aluminium and iron lock; EC is saltiness; organic matter is buffer and holding. NPK still needs crop and yield. Different labs and soil:water ratios cannot be compared digit for digit. Read the measurement, then open the matching field guide.

A sketch. Do not fertilise from the picture alone.

Easy to mix up

  • Looks like “CEC mixed with EC”

    CEC is cation exchange — how many nutrient seats the soil holds. EC is conductivity — how salty the soil water is. One letter apart, two different jobs.

  • Looks like “The sheet as a prescription”

    The sheet gives thresholds. Bag counts live in the field guide, with a local station and the label. A low cell is not an automatic bag.

Do this / don’t do that

  1. 1Match field name, depth, date and soil:water ratio. If they do not match, sample again. Do not amend your field from someone else’s number.
  2. 2Circle pH, organic matter, salt, NPK, then micronutrients. Stop if you misread a unit by one place.
  3. 3When the number matches what the field looks like, open the matching field guide. Rates need a local station and the label. This page does not print a bag count.

Don’t do this first

  • Do not compare digits across labs or soil:water ratios.
  • Do not read the sheet as a bag count.
  • Do not push tea to the grain pH target.

Rate range

Crop × textureTextureRateNote
Any cropRead the sheet firstOrder: pH → organic matter → salt → NPK → micronutrientsFertiliser ranges from the station. This page prints no bag count.

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

Lab-sheet cells
CellLowMidHigh
pHGrain land < 5.5: consider limeCrop-dependentIron locks
Organic matterThin houseCan bufferStill read salt
EC / saltUnlikely salt injuryAsk the outlet first
CECSand cannot hold a dumpCan hold more at once

Anonymous sheet, circled in order

FieldA North China grain field (anonymous)
Sample2026-03-18 · 0–20 cm · 12 points mixed
pH (1:2.5 water)5.2
Organic matter g/kg12.4
EC mS/cm0.28
Available N mg/kg68
Available P mg/kg9.5
Available K mg/kg82
CEC cmol/kg11.2
Available Fe mg/kg4.1

Grain land at pH 5.2 can discuss agricultural lime. Tea at the same 5.2 must not be pushed to neutral. CEC is cation exchange, not EC.

A sketch. Do not fertilise from the picture alone.

One number example

An anonymous grain sheet at pH 5.2, organic matter 12.4 g/kg, EC 0.28: grain land can discuss agricultural lime, sandy soil at the low end, split. Tea at the same 5.2 must not be pushed to neutral. CEC is cation exchange, not EC. Do not copy a US unit table.

The field name on the sheet must be the field you are standing in.

Lesson video

2026-03-08 · 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