CEC
Low CEC needs smaller, more frequent dressings. High CEC can hold more at once.
Speed
- CEC is how many nutrient seats the soil has.
- Low CEC needs smaller, more frequent dressings. High CEC can hold more at once.
- Low-CEC sand will not hold fertiliser.
- Clay and high-organic-matter soils hold a bigger dressing.
How it appears on the sheet
Low-CEC sand will not hold fertiliser. Clay and high-OM soils hold more at once.
A sketch. Do not fertilise from the picture alone.Common units
Often cmol/kg.
How to read the number
Low-CEC sand will not hold fertiliser. Clay and high-organic-matter soils hold more. Texture and organic matter set CEC. You cannot change texture; you thicken organic matter.
Texture is sand or clay; CEC is the holding that follows. Low CEC needs smaller, more frequent dressings. High CEC can hold more at once.
Thresholds only, not a prescription. Rates live in the field guide. This page does not hand you a bag count.
What it looks like in the field
Low-CEC sand will not hold fertiliser. Clay and high-OM soils hold more at once.
Don’t do this
- Pouring a season onto sand in one hit.
- Flooding a low CEC so the meal washes away.
- Texture is sand or clay; CEC is the holding that follows.