Application of Quality Indicators in the Evaluation of Subtropical Argiudolls and Hapludolls in Formosa (Argentina)

The quality indicators are suitable tools to determine the state of the soil and the effects of different uses and management on it. The aim of the present work was to evaluate the quality of sub-tropical Argiudolls and Hapludolls subjected to different uses in Formosa, using a minimum set of indicators (MSI). Changes in soil use and the application of management techniques to maximize agricultural production are frequent in the world. In Formosa, Argentina, improvements in the productive infrastructure and low market value of the land, promote that these changes occur faster than the monitoring of the ones. The effects of 25 years of continuous agricultural use, extensive livestock in implanted pastures and fruit crops, in relation to the native forest were analyzed. The MSI consisted of five variables: total organic carbon, particulate organic carbon, total nitrogen, structural stability and bulk density. The baseline of the indicators was determined and threshold values were established. The standardized MSI was analyzed graphically. Particulate carbon and structural stability were the most sensitive indicators. Continuous agriculture degraded the edaphic system, resulting in lower values of indicators than the thresholds. It produced a decrease of 74% of the particulate organic carbon and 63% of structural stability, with possible impact on the resilience of the system. Fruit crops led to a decrease in soil quality causing particulate organic carbon and structural stability to approach values that compromise their natural recovery. The implanted pasture improved the quality of the soil with respect to the degraded native forest.