Liming Calculator

Chapter 04 says lime 1–3 t/ha months ahead when pH sits below 5.5. This tool turns that guidance into a tonnage using the standard lime recommendation factor — a planning figure, not a lab substitute: use a soil test's exchangeable-acidity (or its own lime recommendation) when available.

Lime needed to lift soil pH to the 6.0 target, by starting pHOn the calculator's model — 2.5 tonnes per hectare of pure calcium carbonate per pH unit over the top 20 cm — a soil at pH 4.5 needs 3.75 t/ha, pH 5.0 needs 2.5, pH 5.3 needs 1.75, pH 5.6 needs 1.0 and pH 5.8 needs 0.5.Soil pH 4.53.75 t/haSoil pH 5.02.5 t/haSoil pH 5.31.75 t/haSoil pH 5.61 t/haSoil pH 5.80.5 t/ha0 t/ha1 t/ha2 t/ha3 t/ha4 t/ha
Data table
Lime to reach pH 6.0, t/ha of pure CaCO₃ over 20 cm
Starting soil pHLime needed
4.53.75 t/ha
5.02.5 t/ha
5.31.75 t/ha
5.61 t/ha
5.80.5 t/ha
The curve the liming calculator uses: 2.5 t/ha of pure CaCO₃ per pH unit over the top 20 cm, against a pH 6.0 target. The chapter's working figure is a flatter 1–3 t/ha below pH 5.5; soil texture moves either number by ±40%, which is why the tool asks for your material and depth.

1.00 ha = 2.47 acres

pH

From your soil test

cm

20 cm typical for ginger beds

Lime needed (your % CCE)—
kg per 100 m²—

Work it in, don't let it sit. Lime reacts slowly — apply 2–3 months before planting and incorporate into the top 15–20 cm, never dump on the surface. If pH is below ~4.5, split the dose into two applications a season apart rather than one huge shock.