Biological Properties of Soils in the Province of Chaco-Argentina with Dif ferent Agricultural Practices

Abstract

Soil quality is defined by its capacity to function within ecosystem boundaries, support productivity, maintain biodiversity, and preserve water and air quality. The diversification of productive activities, both agricultural and livestock-based, contributes to improving soil use. In this context, it is essential to identify indicators sensitive to land-use changes, with biological parameters being particularly suitable for estimating soil quality. The objective of this study was to evaluate the biological properties of soil under various agro-livestock management practices compared to its initial condition in wooded areas: forest soil (considered pristine) (Mon), agricultural
soil (ChAg), and soil with a livestock management history of over 40 years (ChMix). Biological indicators included microbial biomass carbon (MBC), soil respiration (RES), easily extractable glomalin (EEG), potentially mineralizable anaerobic nitrogen (PMN), total organic carbon (TOC), particulate organic carbon (POC), total nitrogen (TN), and particulate organic nitrogen (PON). The results highlight the importance of biological variables as sensitive indicators and quantitative diagnostic tools for decision-making tailored to the conditions of each agroecosystem. The ChMix system displayed intermediate values in most variables, representing a productive alternative with a lower impact on soil quality. The attributes EEG and PMN stood out as good quality indicators, showing significant dif ferences and evidencing changes between pristine and agricultural-livestock conditions. When analyzing the various organic soil fractions, the greatest dif ferences were observed in POC and PON, demonstrating their sensitivity in distinguishing between natural systems and dif ferent agricultural management practices.