CO2 emission affected by moisture content and aggregate sizes in a calcareous soil of Comarca Lagunera, Mexico

Santos Martínez-Santiago,Hilda Victoria Silva-Rojas,Elsa Marcela Ramírez-López,Enrique Ojeda-Trejo,Armando López-Santos,Gerardo Sergio Benedicto-Valdés

doi:10.36783/18069657rbcs20210129

Abstract

Soil CO2 emissions are formed from biotic and abiotic processes related to organic carbon (SOC) and inorganic carbon (SIC), respectively. Calcareous soil has a high amount of SIC and occurs mainly in arid areas, and little is known about CO2 emissions from aggregates of this soil. This study aims to evaluate the emission of CO2 of aggregates from calcareous soil in the Comarca Lagunera, Mexico. Soil samples were taken from the layers of 0.00-0.15 and 0.15-0.30 m, and soil [...]

Highlights

IntroductionSoil contains two forms of carbon: SOC (soil organic carbon) and SIC (soil inorganic carbon) (Mikhailova et al, 2019), and it is considered the third-largest carbon deposit on the planet; it has a key role in this element’s cycle (Wang et al, 2012)
Environmental factors such as soil moisture regulate the mineralization of soil organic matter (SOM) since moisture deficiencies can suppress the activity of the microorganisms (Luo and Zhou, 2006)
The following physico-chemical and chemical properties were determined: pH and electric conductivity (EC) in a soil extract saturated with water, at a ratio of 1:2 (Alexakis et al, 2015); SOC determined by wet oxidation method (Walkley and Black, 1934); SIC determined by water displacement method (Horton and Newsom, 1953); soil total nitrogen (STN) by Kjeldahl method (Bremner, 1996) and carbon/nitrogen ratio (C/N)

Summary

Introduction

Soil contains two forms of carbon: SOC (soil organic carbon) and SIC (soil inorganic carbon) (Mikhailova et al, 2019), and it is considered the third-largest carbon deposit on the planet; it has a key role in this element’s cycle (Wang et al, 2012). The largest amount of carbon in soil is stored organically, but in arid and semiarid areas, inorganic forms are more abundant, mainly in carbonates (Wang et al, 2012). As a main component of SOC, organic residues are used by the soil biotic component for its maintenance, a process known as mineralization in which CO2 emissions are generated into the atmosphere (Kuzyakov, 2006). Environmental factors such as soil moisture regulate the mineralization of soil organic matter (SOM) since moisture deficiencies can suppress the activity of the microorganisms (Luo and Zhou, 2006)

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