Soil liming

[/business/agriculture/soil/lime]

Managed soils methodology, liming treatment. Calculates carbon dioxide emissions (CO2) based on quantities of lime (carbonates) applied. Scenarios include limestone and dolomite. Globally applicable.

Summary

This methodology represents carbon dioxide (CO2) emissions associated with the application of lime (carbonate minerals) to managed soils. The data and calculation methodology is sourced from the IPCC, as published in Volume 4, Chapter 11 - N2O Emissions from Managed Soils, and CO2 Emissions from Lime and Urea Application of their 2006 IPCC Guidelines for National Greenhouse Gas Inventories.


The methodology

Emissions model

Liming is used to reduce soil acidity and improve plant growth in managed systems, particularly agricultural lands and managed forests. Adding carbonates to soils in the form of lime (e.g., calcitic limestone (CaCO3), or dolomite (CaMg(CO3)2) leads to CO2 emissions as the carbonate dissolves and releases bicarbonate (2HCO3-), which evolves into CO2 and water (H2O).

The methodology calculates CO2 emissions based on the mass-balance of carbon (C) applied during treatment. This assumes that all C added to soils is eventually emitted as CO2.

This methodology represents the IPCC Tier 1 approach.

Model data

The precise relationship between the quantity of lime applied and the quantity of CO2 emitted depends on the mineralogy of the lime used, and, in particular, its carbon content. Carbon content (by weight) factors are provided for two carbonate minerals - limestone and dolomite. These values allow the conversion of a quantity of carbonate into a quantity of C.

In addition, this methodology uses a second conversion factor, representing the ratio of the molecular mass of CO2 and the atomic mass of C. This quantity allows the conversion of a quantity of C into the corresponding quantity of CO2. In combination, these two conversion factors enable the conversion of a quantity of carbonate into a quantity of CO2 emitted - under the assumption of mass-balance.

Activity data required

CO2 emissions are directly proportionate to the quantity of lime applied, which therefore needs to be specified in order to make an emissions calculation.

Calculation and results

The CO2 emissions calculated by this methodology represent those attributable to the specified quantity of lime applied to managed soils.


Additional information

Lime applied in fertilizers

According to IPCC advice, lime which is applied to managed soils within a broader mixture of fertilizers should be accounted for using this methodology.


Related methodologies

A number of other methodologies focus on emissions from managed soils. These include those arising from the addition of urine and dung, urea and synthetic and organic fertilizers, as well as organically-managed soils.

 UIDLabel
MGCC7A55YFUX dolomite
5WACDH5GIHKX limestone
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Name: Soil_liming
Full path: /business/agriculture/soil/lime
Parent Category: Soil management
Provenance: IPCC