Home / Blog / Which fertiliser for which soil
Fertiliser
Which fertiliser for which soil: the MPOB F-series without the jargon
Seven product codes, four soil types, one decision. Here’s the whole table, explained once.
Walk into any agro-supply shop serving oil palm smallholders and you’ll see sacks labelled F1, F2, F3, F5, F6, and variants with “Xtra K” or “Super K” in the name. These are MPOB’s standard compound formulations — already blended with nitrogen, phosphorus, potassium, magnesium and boron in ratios tuned for oil palm, so a smallholder doesn’t need to buy and mix single-nutrient fertilisers separately.
Why soil decides the product
Different soils hold and release nutrients differently. Peat is naturally low in potassium and can be acidic; sandy soil drains fast and loses nutrients with it; clay and laterite soils hold nutrients but can lock up phosphorus. MPOB’s F-series exists precisely because one blanket formula doesn’t serve all of these well — the product code is really a soil-matched recipe.
The F-series by soil
| Soil type | Balanced stage | High-K (fruiting) stage |
|---|
| Alluvium (mineral, riverine) | MPOB F1 (AS + DAP) | MPOB F1 Xtra K |
| Peat | MPOB F2 (10.7:9.1:17.3:1.4:0.5B) | MPOB F2 Super K (7:3:30+B+Si+TE) |
| Sandy | MPOB F3 (10:7:19:1.5:0.5+zeolite) | MPOB F5 Super (10:6:19:2.5:0.5+TE) |
| Clay / laterite | MPOB F6 (10:7:18:2.5:0.5B+TE) | MPOB F5 Super |
Every one of these already includes magnesium and boron, so there’s normally no need to buy kieserite or borate separately on top of one of these.
Then age decides the mix
The soil table only picks the product family. Which column — balanced or high-K — depends on the palm’s age: a young, pre-fruiting palm (under 3 years) needs balanced N-P-K for frond and root growth, while a fruiting palm switches to the high-potassium “baja buah” variant, since potassium is what fills the bunch with oil. See our kg-per-palm-by-age guide for how much of it to apply once you’ve picked the product.
Find your product
Calculator
Your product and dose, from soil and age
Palms (at 60/acre)—
Age band—
Recommended product—
Dose per round (every —)—
Bags (50kg) per round—
Matches MPOB’s F-series soil and age-stage guidance. Your actual lot’s soil test, if you’ve had one, always overrides a soil-type guess.
Frequently asked
I don’t know my soil type — what should I use?
MPOB F6 (clay/laterite) is the most common default for mineral soils generally and is a reasonable starting point; a proper soil test from your nearest MPOB or DOA office is worth doing once if you’re unsure.
Can I mix two soil types’ products if my lot has patches of each?
It’s more common to split the lot by the dominant soil in each section and treat them separately, rather than blend two formulations — the ratios are already balanced and mixing them undoes that.
Do I still need extra kieserite or borate?
Not normally — every F-series product already includes magnesium and boron in its formula. Extra is only worth adding if a leaf or soil analysis specifically flags a deficiency.
Never look up the table again
Add your lot’s soil and palm age once, and SawitSync tells you the product and dose every round — with the date it’s due.
Get started free
Product formulations and soil suitability: MPOB F1–F6 technology summaries.