SOIL BIOLOGICAL QUALITY INDEX BASED ON EARTHWORMS (QBS-E) IN STRIP CROPPING VERSUS PURE STANDS: PRELIMINARY RESULTS OF THE ORTOBIOSTRIP PROJECT

Climate change and intensive use of fertilizers and pesticides have reduced soil biodiversity and its longterm provisioning of ecosystem services. Several EU and worldwide initiatives recognize and address these challenges by promoting sustainable agricultural practices, such as use of cover crops, minimum tillage, and crop diversification. These include strip cropping, an agroecological technique consisting in planting different crops in alternating strips in a rotational system. This increases diversification not only in time but also in space. The main aim of this study, which is part of the OrtoBioStrip (OBS) project, is to assess the soil health status in strip cropping compared to pure stands using chemical-physical parameters and the soil biological quality index based on earthworms (QBS-e) over a period of 2 years. Earthworms have long been known to be important contributors to organic matter decomposition, water drainage and food production, and are therefore commonly used as bioindicators. QBS-e is a recently developed index and our further aim is to consolidate its use as a reliable proxy of soil health. Here we present data from the first year of monitoring carried out on 2 farms in Marche region. In spring 2023 strips and pure stands were cultivated with wheat, faba bean and clover, and earthworms were extracted from 30x30x20cm soil monoliths by hand sorting. They were counted and classified into ecological categories and species using morphological keys. Overall, 117 individuals, belonging to 3 ecological categories and 6 species were identified. Preliminary data showed that compared to pure stands, strip cropping did not significantly affect earthworm communities. Earthworms seem to be rather influenced by either fertilization or soil moisture. For the next sampling season, it is planned to use allyl iso-thiocyanate to chemically expel earthworms (including anecic ones) and to increase the number of replicates to improve the sample representativeness. At the end of the project, soil quality and agronomic data will be integrated to better understand overall strip cropping performance.