Agrometeorological assessment of olive cultivation practices in Messenia, Peloponnese, under climate change

As the Mediterranean region is affected by climate change, it is crucial to understand how the variability in meteorological parameters and human activities impacts the natural resources in agriculture. Higher temperatures, reduced precipitation and extreme events like droughts and floods are fundamental variables that contribute to a negative water balance in nature. Additionally, while intensive farming has increased agricultural productivity, concerns about its sustainability and the potential consequences for ecosystems have emerged. Developing natural-based solutions is necessary to address major challenges, including environmental degradation, water scarcity, loss of soil fertility and biodiversity.

This study focuses on integrated olive orchard agroecosystems management in Messenia regional unit, northwest Peloponnese, known for its rich agricultural heritage and olive oil production. Messenia has a Mediterranean climate, characterized by hot, dry summers and mild, wet winters, with a unique topography combining coastal plains and mountain area. In collaboration with local stakeholders we have developed two field experiments to monitor agrometeorological indicators and assess the current agricultural practices regarding soil and water management.: (i)The first experiment is being conducted in a hilly terrain orchard where we have applied a methodology to collect surface runoff and quantify soil erosion after rainfall events in three different treatments (use of herbicides, mowing of natural vegetation and cover crops seeding). (ii) The second experiment is being developed at a different orchard plant over flat terrain, where we are testing three different irrigation practices, namely: rainfed, irrigation based on common local practices and irrigation based on the phenological stages of olive trees. The agrometeorological conditions (e.g. ambient and soil temperature and humidity, potential evapotranspiration, vegetation properties) are monitored at both experiments with ground based instrumentation and airborne remote sensing. The three major aspects under study are soil characteristics, plant growth, and olive oil quality. First results indicate a difference of more than 30% in soil erosion rates for the different cover treatments. An improvement in oil quality without significant changes in olive oil content between rainfed and irrigated treatments is also found during the first year of the experimental study. Both experiments will remain active in the following years, and based on the results of our research we aim to consult local farmers on enhancing the resilience of olive tree cultivation and reducing the environmental footprint.