Estimation of the potential CO2 sequestration and emission capacity of the agricultural soils of the Valencian Community

Abstract

Visconti, F., de Paz, J.M. 2017. Estimation of the potential CO₂ sequestration and emission capacity of the agricultural soils of the Valencian Community. Ecosistemas 26(1): 91-100. Doi.: 10.7818/ECOS.2017.26-1.15

Agricultural soils have capacity to sequester CO₂ in the form of organic matter. However, this capacity has hardly been quantified and mapped for large territories and with a wide variety of crops, such as the Valencian Community. This task is required to properly size the role of agriculture in any strategy to mitigate climate change. In this paper a first estimate of the potential CO₂ sequestration and emission capacity of the agricultural soils of the Valencian Community down to 20 cm depth has been made. This estimate has been carried out based on the average and spatial variability of the agricultural soil organic matter content in homogeneous agro-ecological zones in climate, soil class and land use, and using GIS, geostatistics and map algebra techniques. The sequestration and emission capacities were found to be 24.0 and 22.0 Mt of carbon, respectively. These values are equivalent to roughly ± 8 years of carbon emissions by use of fossil fuels in the Community itself. This sequestering capacity, which could be reached in 15 to 100 years with the global adoption of management practices that foster soil organic matter accumulation, has an important but insufficient effect compared to the current emission rate. In any case, increasing carbon sequestration in soils, either through management improvement or through organic matter incorporation programs, is very important both to improve sequestration capacity and even more to adapt agroecosystems to climate change.