In regions with scarce water resources, as is the case of most of Spain and other Mediterranean countries, a commonly used methodology to regulate the use of irrigation water by farmers is for the regulatory authority to establish a maximum volume, which is controlled through meters installed on farms. Producers of extensive annual crops in these areas have to tackle two significant problems, among others. The first is to decide which crops to grow and the total area to devote to each one for the next crop year, depending on the availability of irrigation water and cropping area. This is complicated by the uncertainty of future weather conditions, especially in the current climate change scenario. The second challenge is to distribute, as efficiently as possible, across the season, the available amount of water in order to achieve maximum crop yields/returns, while avoiding at least the most profitable crops suffering water deficit if adverse climate conditions increase the need to irrigate beyond expected levels and the water resources available. To solve such problems, our research team proposes the development of an optimization algorithm called ORDILS (Optimized Regulated Deficit Irrigation for Limited volumes of irrigation water and Simultaneous crops), which is the result of experience accumulated in national Spanish projects, and other previous European projects. This algorithm, using an initial reference situation, and depending on the water available, as well as the expected crop yields and profitability according to the amount of irrigation water applied, will be able to adapt irrigation scheduling, and even determine the optimum area to be cultivated, with the intention of maximising the farm’s profitability. To demonstrate the applicability of ORDILS a 2-year field experiment with three crops (purple garlic, barley and maize) is being carried out in Albacete (Spain). Thus, three experimental strategies are considered: a) non-deficit irrigation conditions (control); b) the strategy followed by a typical farmer (who attempts to apply non-deficit irrigation and, if water is short, uses the water destined to the least profitable crops to satisfy the water demands of the most profitable; garlic, in this case); and c) the methodology proposed by ORDILS. The aim of the experiments is also to analyse the effect of ORDILS on crop yield, harvest quality and physiological response, the agricultural and economic productivity of the irrigation water and the water footprint, and the profitability of a typical farm managed by this regulation system. The results of the first year were promising but the increase on the final profitability was lower than expected (2%). This resulted from a beneficial distribution of precipitation throughout the growing season that permitted the avoidance of water deficit by garlic and barley during the Spring, the most sensitive period for these crops. Consequently, during this first year the effect of ORDILS was highly conditioned by good climatic conditions for the objectives of the farmer. Nevertheless, under drought conditions it is expected ORDILS can significantly increase the profitability of the farms compared with the profitability obtained by the typical farmer.

How to cite: Domínguez, A., Schwartz, R. C., Martínez-López, H., and Pardo, J. J.: Optimized regulated deficit irrigation for limited volumes of irrigation water and simultaneous crops. The ORDILS methodology, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8516, https://doi.org/10.5194/egusphere-egu23-8516, 2023.

Water use for irrigation has a critical impact on hydrology, ecology, and agricultural productivity. The irrigation water use is determined by (1) the irrigation water volume required per unit irrigated area and (2) the extent of irrigated land. At large scales, the required water volume per unit irrigated area is usually estimated by calculating soil water balances and quantifying the volume of water supply needed to ensure that crop evapotranspiration is at the potential level or at a level minimizing drought impacts on crop yield. Little information is available about the dynamics in the extent of irrigated land, mainly due to the limited observations and investigations at large scales. To fill the above research gap and to test for factors impacting interannual variability in irrigation extent, this study is going to develop a database with 1990-2020 annual irrigated cropland extent for Europe/Eurasia, a region with relatively well data availability, at sub-national resolution. Relationships between annual irrigation extent and factors potentially impacting variabilities in the irrigated area will be tested by using process-based models. The new annual irrigation database will be applied in Community Land Model to quantify differences in dynamics and trends of irrigation water use across the region compared to the use of the current static data products. Consequently, we will analyze the impact of climate variability on the extent of irrigated crops, irrigation water requirements, and irrigation water use. This study will be fundamental for better understanding and qualifying the human impacts on the natural environment and society under climate change, so as to support future scenario forecasts and decision systems, particularly in improving irrigation management.

How to cite: Zhu, W. and Siebert, S.: Towards a dynamic representation of irrigation in land surface models, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8885, https://doi.org/10.5194/egusphere-egu23-8885, 2023.

Providing adequate water supply following the development of society and ensuring the good status of water-dependent ecosystems is becoming increasingly complex. This is particularly relevant in areas characterized by water scarcity and with unfavourable projections due to climate change, such as the Iberian Peninsula. Water is fully allocated in many water resources systems, while environmental water requirements are intensified. Consequently, it is fairly probable that in the medium and long term water demands will not be satisfied with the current reliability. This fact may particularly affect to irrigation water supply, as the most important consumptive water use. We are developing a National Research Project entitled: Climate scenarios and adaptation of water resources systems (SECA-SRH). The main purpose is to generate knowledge that contributes to the design and implementation of climate change adaptation policies that consider simultaneously technical, economic, social and environmental aspects. The increase of the comprehension of water system behaviour allows decisions making and prioritizing water uses. This would help to achieve the sustainability of the management of water resources systems in the medium and long term. In this study, as part of the mentioned project, we analyse the effect of different criteria for the allocation of environmental flows on the sustainability of the water resources systems in Spain, in the current situation (1989-2019). The availability of water is estimated as the maximum water demand for population and agriculture (irrigation) that can be supplied with a given reliability in a given location of the river network and satisfying environmental flow restrictions. The methodology is based on the use of the high resolution WAAPA model. 720 dams with a reservoir greater than 1 hm3 and 1948 sub-basins are considered. The calculation is made at each dam, at the confluences of the main rivers and for the aggregate set of each sub-basin. The results show that the availability of water in a system is very sensitive to changes in environmental flow regimes. The relationship between reduction in water availability and environmental flows is unevenly distributed in Spain. This result may suggest that the implications of increasing the allocation of water to environmental flows may vary, depending on the hydrological regime and storage availability.

How to cite: Bianucci, S. P., Sordo-Ward, Á., Bejarano, M. D., and Garrote, L.: Trade-off between irrigation demands and environmental flows requirements in Spain, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17393, https://doi.org/10.5194/egusphere-egu23-17393, 2023.

While our planet is heating up, mountain terraces may be able to maintain agricultural production systems in a cooler environment than the agricultural plains. Mountain terraces are, however, characterised by diverse growing environments, with highly variable, stony soils, variable plant spacing and canopy cover. This limits the effectiveness of sensor-based technologies for efficient agricultural resource management. The objective of this research is to provide guidelines for informed irrigation decision making in mountain terrace orchards. Over the past four years, we have cooperated with four farmers with irrigated fruit trees on traditional dry-stone terraces in the Troodos Mountains of Cyprus. We installed soil moisture sensors at a different number of locations and soil depths, depending on the soil and terrace characteristics. In the stony soils of the apple terraces we installed sensors 3 locations and 2 depths (10 and 30 cm). In the cherry terraces, we installed 12 sensors at 4 locations and 3 depths (10, 30 and 45 cm) and 2 additional sensors at 10 cm. In the deep soils of the nectarine terraces, we installed sensors at 2 locations and 7 depths (10-70-cm depth). In the stony plum terraces, we installed sensors at 2 locations and 3 depths (10, 25 and 50 cm). We analysed the variability of the soil moisture observations and the effect of the uncertainty of the soil moisture observations on irrigation decision making. In the cherry terrace, results of more than 3600 hourly observations for 14 sensors showed that the average difference between the driest and wettest sensors amounted to 11.6% volumetric soil moisture at 10-cm depth, 6.7% at 30-cm depth and 7.6% at 45-cm depth. The maximum difference between the soil moisture sensors was observed immediately after one of the irrigation events (12 May 2022), showing a difference of 187 mm water in the rootzone between the driest and wettest set of sensors at the 3 depths. Based on the depth-weighted average of all 14 sensors, this event showed a drainage loss of approximately 38 mm of the 55-mm applied irrigation, below the 55-cm rootzone. The sensor-based irrigation advice would have suggested that the farmer should have irrigated maximum 17 mm. If the driest set of sensors at the 3 depths would have been used, the irrigation advice would have been the same, whereas based on the the wettest set of 3 sensors, the advice would have been to irrigate maximum 22 mm. This indicates that even though the the irrigation advice can have a 29% error, 33-mm drainage loss could have been saved with sensor-based irrigation scheduling for this event.   

How to cite: Bruggeman, A., Eliades, M., Djuma, H., Siakou, M., Sofokleous, I., and Zoumides, C.: Can soil moisture sensors support smart irrigation decision making in mountain terrace agriculture?, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16607, https://doi.org/10.5194/egusphere-egu23-16607, 2023.

Abstract. The EM-38 is a Handheld Electrical Magnetic Induction (EMI) device, non-invasive and commonly used for monitoring salinity, mapping bulk soil properties, and evaluating soil nutrient status. The measured data is an electrical conductivity, [mS/m], which was referred to a representative soil volume of 1.0-1.5 m depth and 2.0 m width.

The Data AcQuisition (DAQ) system for EM-38 (Geonics Inc.) conductivity meter, used for recording the spatial variability of the soil bulk electrical conductivity (EC), is expensive, according to the proprietary software, and do not provide detailed, modifiable circuit schematics.

To address these issues, we developed an easy-to-use, modifiable, and inexpensive data acquisition (DAQ) system for EC data recording and spatializing. In particular, this work investigates the feasibility of using a low-cost open-source DAQ system to be installed on an EM-38 conductivity meter (Geonics Inc.). This DAQ system is based on Raspberry Pi and allows collecting speed and position of the EM-38 device by carrying it on a specific designed sled system.

The EM-38 data (± 200mV) were acquired by A/D converter 24 bit and GPS data ($GPGGA, $GPRMC [NMEA 0183]) were obtained by serial input RS232. The Data logger (Raspberry Pi 4) stored the acquired data and transferred it to the server using an internet connection (Router 4G). The control Firmware has been written in Python language. To ensure the accuracy and reliability of the collected data, the system has been evaluated and tested in well-known open-filed (CIRAAA-a reserch center of the University of Pisa), where the spatial variability of the main soil physical properties (i.e. soil texture, organic matter, electrical conductivity) are known.

The performance has been evaluated by comparing the data string with the one generated by a professional DAQ system. The latter includes a CR1000 data logger (Campbell Scientific) to control and store the EC data and integrats a GPS receiver (GPS16X-HVS, Garmin Inc.) which provides the position, velocity, and timing information.

First results allowed to approve the possibility to extract the analogical signal from the device, which is strongly responsive to the variation of the physical properties of the soil environment. Moreover, the device is able to estimate accurately the spatial patterns of the investigated soil physical properties.

Keywords: Precision farming, Zoning, EMI sensors, soil bulk electrical conductivity, open source DAQ

How to cite: Hamouda, F., Bonzi, L., Provenzano, G., Puig-Sirera, À., Sbrana, A., Remorini, D., and Rallo, G.: Analysis of the Feasibility of a low-cost DAQ for EM-38Detection and Mapping, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-389, https://doi.org/10.5194/egusphere-egu23-389, 2023.

The consequences of climate change will affect irrigation also in areas that have so far been little affected by water shortages. In the north-eastern part of Austria with predominantly sub-humid conditions (550 mm mean annual rainfall, 11°C mean annual temperature), water demand is expected to double by 2050. With regard to irrigation, this means both increased crop water requirements and reduced water availability. Improving water use efficiency is one way to sustain agricultural productivity and water resources in the long term. This poses a future challenge also for farmers who have had little to do with the requirements of highly efficient irrigation management so far. In this regard, a potential on-farm strategy is to monitor soil water status and control irrigation based on the plant available soil water. On the technical side, sensors and telemetry networks are available that regularly collect and transmit data. However, the appropriate thresholds for irrigation control must also be known. These depend on the crop, the root development, the soil type and the installation depth of the sensors. Last but not least, farmers need to trust the decision support and use the information appropriately. The aim of this study was to determine threshold values ​​for the irrigation of maize at a location in north-eastern Austria (in the country's largest arable farming area, approx. 35 km east of Vienna) and to subject them to a practical test in the field.

The irrigation system used was a hose reel with an irrigation boom with rotating nozzles (BAUER GmbH). HydraProbe (Stevens Water Monitoring Systems Inc.) and Watermark (Irrometer Company Inc.) sensors were used to measure soil water content and matric potential, respectively. The sensors were integrated into a telemetry network (ADCON by OTT HydroMet GmbH); data were available via a web-application. For practical reasons, the installation depth of the sensors was set at 20 cm. Soil was a sandy loam. A target value for the maximum allowed depletion under optimal to slightly stressed conditions was calculated using a water balance model. Based on HYDRUS-1D (PC-Progress s.r.o.) simulations, the corresponding matric potential at 20 cm depth was −100 kPa. This value should serve as the target value for irrigation. The soil water content data served as a control for the simulation using the FAO AquaCrop model. The latter was used to evaluate the irrigation carried out by the farmer.

The soil water data revealed that the specified threshold was not reached in the practical test. It seems that farmers experience was oriented towards a more sufficient water supply. The simulation showed that water use efficiency could have been improved by using less water; however, in this case a reduction in yield of a few percent would have to be expected. Measuring with only one sensor at a depth of 20 cm proved to be a viable procedure; however, data interpretability could be improved by sensors at several depths.

How to cite: Faller, C. and Nolz, R.: Assessing soil water thresholds for irrigation of maize in north-eastern Austria, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15370, https://doi.org/10.5194/egusphere-egu23-15370, 2023.

SUDS were initially conceived for mimicking hydrological original conditions of urban catchments. SUDS have been strongly promoted by public and private decision-makers around the world. Public perception has been previously addressed by different studies many studies in a disconnected manner and at different planes. Similarly, the social benefits have also been studied from different perspectives mostly enhancing local perspectives not clearly comparable between territories. In this work we present the initial literature review on SUDS social aspects and public perception. We find from the previous studies that a general method for both making society aware of SUDS aims and roles and providing designers and planners with public perception is clearly lacking. We seek to highlight the gaps to be filled with further analysis and studies so public society can be completely engaged in SUDS design and operation.

How to cite: Zubelzu, S., Cuevas, B., Bernal, C., Esteve, P., Gómez, M. T., López, J., and Rodríguez, L.: Are ongoing SUDS design and management routines considering public perception?, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9004, https://doi.org/10.5194/egusphere-egu23-9004, 2023.

Knowledge of the water status in commercial vineyards is of great importance when defining the production objectives and the composition of the grape must. Determining the appropriate irrigation doses allows for adjusting the balance between vigour and productive capacity of the vineyard. However, to accurately know the hydration status of the vines, it is necessary to use equipment such as pressure chambers that are hardly replicable. Much effort has been invested in finding a more straightforward simpler methodology that allows knowing the hydration of plants. In this respect, remote sensing technology is presented as an appropriate tool to obtain information from large areas quickly and efficiently. This work aimed to evaluate the accuracy of water stress detection based on thermal sensors onboard UAVs.

The study was carried out in the Merlot vineyard located in Toledo-Spain; arranged on a trellis with a 2.60 x 1.10 m planting frame and established in 2002. High-resolution thermal images were obtained on different dates during the 2021 and 2022 irrigation campaign and at two intervals of the day (9:00 and 12:00 solar hours). Stem water potential (Ψm) and chlorophyll were measured at the same time.

The results indicate that there are statistically significant differences between the different irrigation treatments. These differences were mainly observed in the water-steam potential measurements made in the morning.

References

Acevedo-Opazo, C., Tisseyre, B., Guillaume, S., & Ojeda, H. (2008). The potential of high spatial resolution information to define within-vineyard zones related to vine water status. Precision Agriculture, 9(5), 285–302. https://doi.org/10.1007/s11119-008-9073-1.

Jackson, R. D. (1982). Canopy Temperature and Crop Water Stress. 1, 43–85. https://doi.org/10.1016/b978-0-12-024301-3.50009-5.

Poblete-Echeverría, C., Sepulveda-Reyes, D., Ortega-Farias, S., Zuñiga, M., & Fuentes, S. (2016). Plant water stress detection based on aerial and terrestrial infrared thermography: A study case from vineyard and olive orchard. Acta Horticulturae, 1112, 141–146. https://doi.org/10.17660/ActaHortic.2016.1112.20.

Acknowledgements:

The authors want to thank Bodegas y Viñas Casa del Valle for allowing us to work in their vineyards and the company UTW for supply the drone images. Financial support provided by Comunidad de Madrid through calls for grants for the completion of Industrial Doctorates IND2020/AMB-17341 is greatly appreciated.

How to cite: Atencia, L. K., del Campo, M. V., Nowack Yruretagoyena, J. C., Tarquis Alonso, A. M., and Hermoso Peralo, R.: Detection of plant water stress in Merlot vineyard using thermal sensors onboard UAVs, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16111, https://doi.org/10.5194/egusphere-egu23-16111, 2023.