Impact of land use on soil organic carbon storage in the Northwestern Dry Chaco

Abstract

1. Soil organic carbon (SOC) stock is an indicator of soil quality and health. Its dynamics play a significant role in the global balance of greenhouse gas (GHG) emissions. Changes in land use and increased production intensity in the Dry Chaco region decrease SOC.
2. The objective of this study was to compare the effect of different land uses and soil textures on SOC storage in the Dry Chaco. Using the equivalent mass methodology, three production systems were compared: extensive agriculture, planted pastures, and forest with livestock. Data were obtained from soil samples taken at depths of 0–10 cm and 10-30 cm for each land use and texture.
3. The results showed no significant differences in SOC among the evaluated land uses; however, significant differences were observed across soil textures, suggesting that soil characteristics, environmental variability, and plot-level management play a significant role in SOC reserves.
4. Soil compaction and increased bulk density occur after deforestation. This situation does not occur in forest-livestock use (i.e., forest with livestock) , which, although not subject to deforestation, is susceptible to desertification and SOC loss, especially in coarse-textured soils.
5. The storage of SOC in fine-textured soils under planted pastures is noteworthy.
6. Implications. The potential of extensive agriculture and forest-livestock land uses to sequester carbon in finetextured soils through sustainable management practices is highlighted. Edaphic and environmental variability must be considered in future monitoring and management strategies for SOC in the region.