Impact of Cover Crops on Carbon Sequestration, GHG Emissions, and Soil Health in Mediterranean fruit tree orchards (CLIMCOVER Project)

This dataset presents the comprehensive results of a two-year research initiative conducted within the framework of the CLIMCOVER project, focusing on sustainable intensification in modern fruit tree cultivation. The study specifically evaluates the transition from traditional bare soil management to the use of cover crops, with the primary objective of quantifying the benefits of this agroecological practice regarding soil health, climate change mitigation, and ecosystem multifunctionality. By integrating agronomic, physicochemical, and high-throughput molecular indicators, the data facilitates a comparative evaluation of cultivation systems. The dataset includes detailed site metadata and environmental characterization—providing coordinates, climatic variables (temperature, precipitation, and evapotranspiration), and topographical features—alongside in-depth documentation of agricultural management practices, such as tillage, fertilization, and irrigation, all contextualized through specific case study codification. A significant portion of this research is dedicated to selecting and evaluating the effect of cover crops on Carbon (C) sequestration and the reduction of Greenhouse Gas (GHG) emissions. To ensure high-precision data for climate change mitigation and C farming markets, soil profiles were opened in each plot to identify horizons and sample for inorganic and total organic C. This allows for a robust comparison of soil carbon storage across the entire depth between long-term cover crop implementation and traditional monoculture profiles. Furthermore, direct emissions of CO2, CH4, and N2O were measured monthly over one year using the dynamic gas chamber technique connected to a photoacoustic infrared spectroscopy multi-gas analyzer. These measurements, captured every minute for 5-minute periods to assess linear trends, provide a real-world assessment of how cover crop management affects GHG emissions. To complement soil and gas data, the study incorporates tree biomass assessments by uprooting trees at the beginning and end of the experiment to measure C content in roots, trunks, stems, and leaves. C sequestration in cover crops was similarly assessed through early summer quadrant sampling (1 m2). All carbon analysis for soil and biomass was performed using an elemental CHNS-O analyzer (EA-1108, Carlo Erba). Overall, this dataset provides a holistic view of carbon cycling and storage, bridging the gap between potential and real GHG emissions within modern orchard ecosystems.