Start / Soil and fertilization / Liming and fertilization
Enter the CEC, current saturation, and the crop's target to find out how much limestone to apply per hectare, corrected by PRNT.
Pre-sizing and estimating tool: the results do not replace a design, calculation, or report signed by a qualified professional, nor verification against the applicable standards.
Tonnes per hectare for each V2 target; the dot marks your target.
How much limestone the same correction requires at different PRNT values; the highlighted bar is your limestone.
Drag the controls to simulate data different from what you entered (from 30% less to 30% more) and watch the result change instantly.
Limestone dose (t/ha) for combinations of desired base saturation (V2) and PRNT, with the CEC, current saturation, and depth entered.
The calculation done in steps, with the values you entered.
The calculation memo gathers this page's inputs, results, equations, assumptions, and references, with fields for project, responsible person, and review. The full report also includes the charts and interpretations, in color. In the print window, choose Save as PDF.
Take the soil analysis report for the 0 to 20 cm layer and note the CEC at pH 7 (T) and the current base saturation (V1). Enter the desired saturation (V2) for the crop, the limestone PRNT, which is on the report or the label, and the incorporation depth. The result comes out in tonnes per hectare and in total for the area.
Soil with T = 10 cmolc/dm³, V1 = 35%, target V2 = 60%, limestone with 85% PRNT, incorporated to 20 cm, area of 50 ha.
NC = 10 × (60 − 35) ÷ 85 × (20 ÷ 20) = 2.94 t/ha. For the 50 ha, it is about 147 t of limestone.
Agricultural limestone is classified by its magnesium oxide content. PRNT combines neutralizing power with grind fineness (reactivity): the higher it is, the faster and more complete the effect per kilo applied.
| Type | MgO | When to choose |
|---|---|---|
| Calcitic | up to 5% | soil with adequate magnesium |
| Magnesian | de 5% a 12% | low to medium magnesium |
| Dolomitic | above 12% | low magnesium |
After correcting the acidity, calculate the blend in the NPK fertilization and check the total cost in the production cost per hectare.
From soil analysis: with the CEC, current saturation and crop target, the base saturation calculation gives the dose in tonnes per hectare, corrected by the limestone PRNT.
It is the efficiency of the limestone relative to pure calcium carbonate. A limestone with 80% PRNT needs more product than one with 100% for the same effect. The value is on the lab report.
Depends on the crop and your state's recommendation. The most common values are between 50% and 70%; confirm in the regional fertilization and liming manual before deciding.
Ideally two to three months before planting, to give the soil time to react, and well incorporated into the layer to be corrected.
The dose varies in proportion to depth relative to 20 cm: for 10 cm, half; for 40 cm, double.
The choice depends on the soil's magnesium. With low Mg, magnesian or dolomitic lime corrects acidity and supplies magnesium; with adequate Mg, calcitic lime is enough.
No. The calculation depends on the CEC (T) and the current saturation (V1), which only come from the soil analysis. Without the report, the dose is a guess, with risk to the crop and to the cost.
Important notice: the Agrocalcs tools make estimates and preliminary sizing based on the data entered and on published engineering methods. They do not replace a design, a calculation report or a report signed by a qualified professional (CREA/ART), nor verification against the applicable technical standards and legislation, such as the Regulatory Standards of the Ministry of Labor. Material and fuel properties vary: check with the manufacturer or with analyses of your process before deciding. By using the site, you agree to the Terms of Use.
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