INFLUENCE OF GROUND COVER AND SOIL PROPERTIES ON BIOLOGICAL SOIL QUALITY IN ECOSYSTEMS OF THE PO VALLEY

The characterization of the soil physicochemical properties together with the knowledge of the biological diversity associated to this substrate are fundamental to assess the soil quality and to support political decision relative to agricultural and natural ecosystems. The soil is a complex environment in which different taxa (bacteria, fungi and metazoan) play a fundamental role in regulating the organic matter decomposition and nutrient recycling, influencing the ability to maintain the ecosystem services and agricultural production sustainability. In the early 2000s QBS-ar index (Qualità Biologica del Suolo – artropodi) was developed and arose as one of the most used indexes to assess soil biological quality. This index assigns a morphometric score, based on the level of adaptation to edaphic environment, to arthropods extracted through Berlese funnel from soil samples. In this project we collected soil samples from environments with different ground covers (grapevine, corn, rice, mixed forest, alfalfa, stable meadow), for each sample we measured physicochemical properties (i.e., texture, pH, organic carbon and nitrogen) and computed the QBS-ar index. The analysis of variance and a subsequent post-hoc comparison showed a subdivision of the crop into two different groups: the first containing corn, rice and alfalfa 1-3 years and the second with grapevine, mixed forest and alfalfa 4-5 years. The stable meadow is found in both groups. Among the different physicochemical properties analyzed, organic carbon and nitrogen positively correlate with the QBS-ar, while the percentage of sand in the soil correlates negatively with the index. These results support the conclusion that less disturbed soil can sustain higher biological diversity.