INTEGRATED VASCULAR ANALYSIS SYSTEM OF OLIVE CULTIVATION: SAVIA OLIVAR PROJECT

María Ester García-Bermúdez¹Antonio Aguirre-Arcos^1*Irene Ortiz-Bernad¹Juana Nieto Carricondo^2,3Antonio M. Lallena⁴Marino Pedro Reyes-Martín¹Álvaro Ávila- Pérez³Emilia Fernández-Ondoño¹

• ¹Departamento de Edafología y Química Agrícola, Facultad de Ciencias, Universidad de Granada, Granada, Spain
• ²Caja Rural de Jaén, Jaén, Andalusia, Spain
• ³Olivarum. Fundación Caja Rural de Jaén, Jaén, Spain
• ⁴Departamento de Física Atómica, Molecular y Nuclear, Facultad de Ciencias, Universidad de Granada, Granada, Spain

Olive trees are widely cultivated crops, especially in Mediterranean countries, which requires new practices to maintain productivity, optimize resource use and improve the quality of the environment. Integrated production seeks to achieve these objectives, but this requires rapid and effective methods to plan crop nutrition. Sap extracted using a modified Scholander chamber could provide an accurate method for determining the nutritional status of olive trees. To verify this, two trials were conducted in integrated production systems in southern Spain over two periods of time (2018-1019 and 2022-2024). The trials were carried out in five farms in the provinces of Jaén, Granada and Seville, comparing the nutrient concentrations in sap, leaves and soil from Picual and Hojiblanca olive trees.In the first period (2018-2019), critical times when nutrient flux in the sap increased were identified as spring, early fall, winter, and the first half of July. These periods were selected for sampling in the second period (2022)(2023)(2024). Sap, leaves and soil were analyzed, determining macro-and micronutrients, pH and electrical conductivity. In the first trial, monthly sampling was successful, although in autumn 2022, a very dry year, little sap was extracted. From April 2023 onwards, the amount of sap recovered, which demonstrated the sensitivity of sap extraction to climatic variations and the phenological state of the olive tree.Soil analyses showed pH from 7.9 to 8.5 and electrical conductivity from 1.1 to 5.9 dS m -1 . Nutrient concentrations in leaf were higher than in soil and in soil higher or equal than in sap, except for K, the most abundant element in sap, with concentrations exceeding those in soil. Concentrations of Fe, Cu, Mn and Zn increased in 2022 compared to 2018, possibly due to climatic differences. Sap analysis can complement leaf and soil analyses for a more balanced fertilisation in olive orchards.