REUTIVAR 2.0 Operational Group: Advances in the sustainability of olive grove irrigation with reclaimed water

The project "Advances in the Sustainability of Olive Grove Irrigation with Reclaimed Water (REUTIVAR 2.0)" will undoubtedly yield promising results and offer knowledge and advances to continue developing innovative and sustainable management in the olive grove sector. However, the revitalization and competitiveness of the olive grove sector in general, and specifically that associated with irrigation using non-conventional resources such as reclaimed water, continues to require knowledge and advances that will strengthen the development, innovation, sustainability, and management of olive groves in a context increasingly undermined by the effects of climate change. Where:

• Irrigation with reclaimed water in accordance with its intended use and in compliance with the qualities required by the new Regulation EU2020/741 regarding minimum requirements for water reuse.
• The implementation of treatment technologies appropriate to their end use, in accordance with the globally recognized “fit for purpose” concept.
• The management of the risk associated with the use of such waters.
• Greater efficiency in the use of reclaimed water through the expansion of precision fertigation, in line with the use and development of Information and Communication Technologies (ICT).
• Promoting the circular economy through water reuse.
• The recovery of nutrients for application to crops using fertigation techniques, and the production and recovery of fertilizers from wastewater treatment plant sludge (the starting point in the water regeneration process) through the use of renewable energy sources.
• Evaluating the quality of the fruit and oil will undoubtedly yield results and provide insights and advances to continue developing innovative and sustainable management in the olive sector.

Therefore, this project faces the following challenges:

• Adapt olive groves to the requirements established in the new Regulation EU2020/741 on minimum requirements for water reuse in agriculture, including, among other aspects, new minimum requirements for water quality and control and provisions on risk management.
• Implement water treatment technologies appropriate for the end use of the olive grove, in accordance with the globally recognized "fit for purpose" concept.
• Increase the efficiency of reclaimed water use by expanding precision fertigation in conjunction with the use and development of Information and Communication Technologies (ICT).
• To analyze in depth the spatio-temporal evolution of reclaimed water quality in the irrigation network, including nutrients and other elements that contribute to the occurrence of clogging phenomena.
• The promotion and implementation of the circular economy through water reuse, nutrient recovery for crop application using fertigation techniques, and the use of renewable energy sources to produce products derived from wastewater treatment plant sludge for remediation of degraded soils, which are potential opportunities for olive cultivation in rural areas.
• The evaluation of productivity, as well as the quality of the fruit and oil.
• When applying innovation to sustainable water management in olive irrigation, there is a significant body of related, and largely dispersed, scientific and technological knowledge that must be leveraged and made available to the sector. There is also a need to create links and enhance synergies between cutting-edge knowledge and stakeholders in the sector. To achieve this, Reutivar 2.0 establishes the following specific objectives:
  • Water quality assessment, according to the criteria established in the new Regulation (EU) 2020/741, regarding the minimum requirements for the reuse of water for drip irrigation of olive groves.
  • Progress in developing a specific risk management plan for irrigating olive groves with reclaimed water.
  • To further develop precision fertigation techniques for olive groves using reclaimed water, considering the spatiotemporal variability of nutrient input across different plots.
  • Optimization of the ring filtration system by monitoring and evaluating different micron sizes.
  • Recovery of by-products (sewage sludge) and generation of dried sludge using solar thermal energy for the remediation and fertilization of soils used for olive cultivation.
  • Promoting synergies and the transfer of knowledge and innovation among stakeholders in the sector and developing the knowledge base in rural areas.
  • Promote the raising of economic resources in rural areas.

The main expected results derived from the actions carried out in the REUTIVAR 2.0 project are:

• Assessment of wastewater quality in the various treatment units of the Montilla-Sector I CR Tintín WWTP complex.
• Evaluation of the spatiotemporal variation in the concentrations of the main elements during an irrigation season and their impact on fruit and oil quality.
• Calibration of the Epanet model to reproduce the distribution of these elements in the irrigation network.
• To delve deeper into precision fertigation techniques for olive groves using reclaimed water and to make precise recommendations on the fertilizer applications required for each area of the irrigation community.
• Evaluation of the spatio-temporal variation in the quality of reclaimed water in the irrigation network.
• Evaluation of the spatio-temporal variation in water quality in relation to parameters associated with potential obstructions in the irrigation network.
• Detailed information on the performance of three automatic ring filters with three different filtration levels (55, 70, and 130 microns) fed with treated wastewater, offline storage of the information, and evaluation of the filtered water quality.
• Detailed information on the thermal drying performance of sludge from the Montilla WWTP in the thermal drying prototype installed at the Carrión de los Céspedes Experimental Plant, Seville.
• Detailed information on the quality of dried sludge for use in remediating degraded soils, potential users for olive cultivation in rural areas.
• Progress in the development of the main elements, actions, and/or measures to be included in the risk management plan for irrigating olive groves with reclaimed water.
• Contribute to promoting synergies and the transfer of knowledge and innovation among the various stakeholders in the sector.
• Contribute to the implementation of the current Hydrological Plans of the Guadalquivir Hydrographic Confederation and the Ministry of Environment and Land Use Planning, which allocate 20 and 150 hm3 of reclaimed water, respectively, primarily for olive grove irrigation, as well as to current agricultural, environmental, and natural resource conservation policies.