Abstract
Grazing and silvopastoral systems represent effective strategies for enhancing soil organic carbon (SOC) and total nitrogen (TN) availability in sodic soils. This study conducted a comprehensive assessment over a 6-year period to evaluate alternative cattle production methods aimed at increasing SOC and TN levels across various soil depths. Mineral-associated organic carbon (AOC) and particulate organic carbon (POC) fractions were analyzed to elucidate the dynamics of SOC. The experimental plots, totaling 9 hectares each, included pure pasture (PP), silvopastoral systems under tree canopy (SPS-UC), and silvopastoral systems between tree canopies (SPS-BC), all cultivated with Chloris gayana cv Epica INTA-Pemán. Trees of Neltuma alba (syn. Prosopis alba) were planted in the silvopastoral area in 1998. Statistical analyses focused on evaluating the impacts of these treatments, temporal effects, and their interactions on SOC, POC, AOC, and TN across four measurement points. Significant differences were observed in the distribution of SOC, POC, AOC, and TN between PP and SPS systems. Notably, SPS-BC exhibited the lowest SOC and TN values. Both PP and SPS-UC showed increases in SOC within the top 50 cm of soil depth, primarily attributed to elevated AOC levels. These findings underscore the potential of grazing and silvopastoral systems in increase soil fertility by increments in soil organic matter to mitigate sodic soil limitations. Moreover, the study highlights the necessity for further research in silvopastoral systems, with a high possibility in implementation for livestock production in Dry Chaco, to investigate how different tree configurations influence SOC and TN dynamics in these soils.