Optimization of Olive Tree Irrigation Using the DRIP Irrigation Decision Support System
Authors: Daliakopoulos Ioannis , Louloudakis Ioannis , Papadimitriou Dimitrios , Sabathianakis Michalis , Christoforakis Ioannis , Matsoukas Theofilos , Zotos Nikolaos , Moysiadis Theocharis , Anastasopoulos Konstantinos , Mavrogiannis Ioannis , Manios Thrassyvoulos 
Published: March 2022

&lt;p&gt;Population rise and economic growth put additional pressure on global water resources, especially in the Mediterranean Island states that have a long history of aridity and water management challenges. In Crete, Greece, 81.2% of total water consumption is attributed to the agricultural sector, with olive trees covering 64.2% of the total cultivated land. Simulation and applied studies have shown that Irrigation Decision Support Systems (IDSS) can reduce water consumption from 10 (Fotia et al., 2021) to 34% (Phogat et al., 2014). Here we examine the feasibility of optimizing such a IDSS for deficit irrigation while maintaining olive crop yield. Experiments are conducted in the DRIP Project infrastructure (Daliakopoulos et al., 2020; Petousi et al., 2018) including an olive grove of 90 10 year-old trees and 5 20m3 lysimeters planted with olive trees from the same olive grove. The infrastructure includes a precision irrigation system comprised of FDR soil moisture sensors, microclimatic stations, and smart irrigation schedulers. The CROPWAT model (Smith et al., 2002) is calibrated using data from 5 irrigation treatments ranging from overirrigation to rainfed cultivation. Field measurements included stomatal conductance [mmol cm-2 s-1], relative chlorophyl fluorescence [Fv/Fm], leaf relative water content [%], leaf area [%], pruning weight [kg], and yield [kg]. Results clearly highlight the differences in olive tree physiological parameters in deficit irrigation treatments and the lack of significant yield benefit in over-irrigation, while the modeling study can estimate exact irrigation scheduling for incorporation with the IDSS.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Acknowledgments&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;This research has been co-financed by the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship and Innovation, under the call RESEARCH-CREATE-INNOVATE (project code: T1EDK-03372)&lt;/p&gt;&lt;p&gt;&lt;strong&gt;References&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;Daliakopoulos, I. &amp;#925;., Papadimitriou, D., Matsoukas, T., Zotos, N., Moysiadis, H., Anastasopoulos, K., Mavrogiannis, I., &amp; Manios, T. (2020). Development and Preliminary Results from the Testbed Infrastructure of the DRIP Project. Proceedings, 30(1), 64. https://doi.org/10.3390/proceedings2019030064&lt;/p&gt;&lt;p&gt;Doorenbos, J., &amp; Pruitt, W. O. (1975). Guidelines for predicting crop water requirements. Irrigation and Drainage Paper.&lt;/p&gt;&lt;p&gt;Fotia, K., Mehmeti, A., Tsirogiannis, I., Nanos, G., Mamolos, A. P., Malamos, N., Barouchas, P., &amp; Todorovic, M. (2021). Lca-based environmental performance of olive cultivation in northwestern greece: from rainfed to irrigated through conventional and smart crop management practices. Water (Switzerland), 13(14). https://doi.org/10.3390/w13141954&lt;/p&gt;&lt;p&gt;Petousi, I., Daliakopoulos, I. N., Matsoukas, T., Zotos, N., Mavrogiannis, I., &amp; Manios, T. (2018). DRIP: Development of an Advanced Precision Drip Irrigation System for Tree Crops. TERRAENVISION Abstracts, 1, 2018&amp;#8211;2. https://terraenvision2018.eu/abstracts/export.php?id=269&lt;/p&gt;&lt;p&gt;Phogat, V., Skewes, M. A., Cox, J. W., Sanderson, G., Alam, J., &amp; &amp;#352;im&amp;#367;nek, J. (2014). Seasonal simulation of water, salinity and nitrate dynamics under drip irrigated mandarin (Citrus reticulata) and assessing management options for drainage and nitrate leaching. Journal of Hydrology, 513, 504&amp;#8211;516. https://doi.org/10.1016/j.jhydrol.2014.04.008&lt;/p&gt;&lt;p&gt;Smith, M., Kivumbi, D., &amp; Heng, L. K. (2002). Use of the FAO CROPWAT model in deficit irrigation studies. In Deficit irrigation practices.&lt;/p&gt;