Comparison of Two Methods for Total Inorganic Carbon Estimation in Three Soil Types in Mediterranean Area

Abstract

The objective of this study was to compare the results of calcimetric and dry combustion methods for quantitative estimation of soil total inorganic carbon (TIC). To this aim, 117 soil samples from three localities in the Mediterranean area (one in Spain and two in Southern Italy), representing a wide range of total inorganic carbon contents (ranging from 1.9 to 54 g 100g−1), were collected. TIC (expressed as CaCO3) was quantified using the volumetric calcimeter method, as reference, and dry combustion in order to find an accurate and rapid method, suitable for different types of soils. The results revealed a concordance between the two methods compared, as shown by the recovery values close to one, for the whole data set and for data grouped per experimental site. Specifically, the dry combustion method showed slightly greater values of TIC compared to volumetric method, probably due to soil acid pretreatments, in dry combustion, and to an incomplete decomposition of carbonates that would require more time for removal, in a calcimeter method. Linear regression equations between the two methods were not affected by different soil types. Overall, our study demonstrated that the dry combustion was a reliable method and could provide accurate estimates of TIC in soils with different calcium carbonate content.

Natural and Human-Induced Factors on the Accumulation and Migration of Pedogenic Carbonate in Soil: A Review

“…Díaz-Hernández et al [42] showed that tracking δ 13 C and δ 18 O is useful for describing pedogenesis of inherited and neo-formed dolomites formed under various geochemical conditions within the vertical soil profile. In another study, these authors explained the formation of deep dolomite vs. surficial calcite through distinguished δ 18 O values (with more negative values attributed to calcite) [15].…”

“…SIC is usually found in the form of calcite (CaCO 3 ) [14], although a significant contribution of dolomite (CaMg(CO 3 ) 2 ) has been reported in a few studies [5,15,16]. Recently, there has been greater research interest in evaluating the SIC pool and its impact on the global C budget [10,17,18], and this trend overcomes the prior neglect of the SIC pool, in the context of climate change mitigation, as it had been traditionally viewed as being less dynamic compared to its organic counterpart [7,19].…”

“…The SIC pool is categorized into two components, lithogenic carbonate (LC) and pedogenic carbonate (PC), with the former originating from the parent material of soil (e.g., limestone or carbonate-rich unconsolidated sediment) [10,18]. The dissolution-reprecipitation of LC, as well as the mechanism of solvation of CO 2 (g) in soil moisture (as CO 3 2-/HCO 3 -) followed by its precipitation with Ca-and Mg-ions, lead to the formation of PC [17].…”

Determination of Total Mercury and Carbon in a National Baseline Study of Urban House Dust

“…TC is quantified by the complete oxidation of all of the carbon forms present in a sample, whereas TOC is determined by first eliminating TIC from the sample using an acid treatment [23]. Based on this relationship (TC = TOC + TIC), the indirect quantification of TIC is typically performed by quantifying TC and TOC, then calculating TIC by subtraction [25,26].…”

Determination of Organic Matter by Using Titrimetric and Loss on Ignition Methods for Northern Iraqi Governorates Soils

“…Loss on ignition (LOI) is one of the widely used methods for estimation of soil organic matter, soil organic carbon in agriculture, forest soils and sediments. It is characterized by simple, quick, inexpensive, safe and less labor-intensive procedures compared with Walkley and Black (Titrimetric method) [9]. The loss of soil mass at high temperatures (500-575 ºC) as a result of oxidation is proportionally related to soil organic matter content (10).…”