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Due to the edaphoclimatic conditions in southeast Spain, which are expected to worsen due to climate change, more efficient ways of using water must be found to maintain sustainable agriculture. Due to the current high price of irrigation control systems in southern Europe, 60–80% of soilless crops are still irrigated, based on the experience of the grower or advisor. The hypothesis of this work is that the development of a low-cost, high-performance control system will allow small farmers to improve the efficiency of water use by obtaining better control of soilless crops. The objective of the present study was to design and develop a cost-effective control system for the optimization of soilless crop irrigation after evaluating the three most commonly used irrigation control systems to determine the most efficient. Based on the agronomic results comparing these methods, a prototype of a commercial smart gravimetric tray was developed. The device records the irrigation and drainage volumes and drainage pH and EC. It also offers the possibility of determining the temperature, EC, and humidity of the substrate. This new design is scalable thanks to the use of an implemented data acquisition system called SDB and the development of software in the Codesys programming environment based on function blocks and variable structures. The reduced wiring achieved by the Modbus-RTU communication protocols means the system is cost-effective even with multiple control zones. It is also compatible with any type of fertigation controller through external activation. Its design and features solve the problems in similar systems available on the market at an affordable cost. The idea is to allow farmers to increase their productivity without having to make a large outlay. The impact of this work will make it possible for small-scale farmers to have access to affordable, state-of-the-art technology for soilless irrigation management leading to a considerable improvement in productivity. [ABSTRACT FROM AUTHOR]

Irrigation is one of the main users of water worldwide and its overuse may affect the natural regimes of water systems. To avoid this, drainage and irrigation management needs to be improved. This study aims to determine the amount of water lost to drainage in a semi-arid Mediterranean irrigated area. Water use, rainfall and drainage were monitored for 12 months (2019–2020) in a 425 ha sub-basin in the Algerri-Balaguer irrigation district (8000 ha, NE Spain). In addition, irrigation requirements were estimated using the single-crop FAO-56 method and a two-source energy balance model (TSEB) was used to estimate actual evapotranspiration in the sub-basin. Water lost to drainage in the sub-basin was estimated as 18% of the total water that entered the perimeter as irrigation and rainfall, which are almost five time higher than theoretical requirements of leaching. Out of the total drainage water, 57% was estimated to be irrigation water and 43% rainwater. The average amount of irrigation water used was 614 mm and irrigation efficiency in the sub-basin was estimated at 80.2% and averaged actual evapotranspiration at 1144 mm. The available margin of improvement is between 19.3% of the present irrigation drainage ratio and the 3.8% estimated with the leaching requirement model. [ABSTRACT FROM AUTHOR]

This study analyses the collective management of irrigation water in 42 WUAs operating in agricultural regions of Italy, Spain and Turkey. The Principal Component Analysis (PCA) and Agglomerative Hierarchical Cluster Analysis (AHCA) are used for benchmarking the technical and financial performance of the WUAs. The analysis shows that the Spanish WUAs, which have less staff (–90%) and higher revenue collection (-53%), perform better than the WUAs of the other two countries. PCA and AHCA indicate that the technical and financial performance of the Turkish and some Spanish WUAs are similar. The Italian and Turkish associations have very large irrigation areas, and WUAs, which may be one of the reasons for the poor management in some organization areas of these countries. Specifically, Italy has excessive Management, Operation and Maintenance costs (up to 1500 €/ha-yr) and large staff numbers (5 persons per 100 ha of irrigated area), while Turkey has high water waste (up to 15000 m3/ha-yr) and insufficient revenue collection (about 60%). Based on the benchmarking results, recommendations are made, to improve the water use and financial performance of the Italian and Turkish WUAs. [ABSTRACT FROM AUTHOR]

Endocarp development in olive trees includes three periods: growth (Period I), massive sclerification (Period II) and maximum hardening (Period III). The two first are strongly related to yield and irrigation management. Period I was reported to coincide with mesocarp cell division and thus with final fruit size. Period II was considered to be the most drought-resistant phenological stage. However, little is known in olive trees about the length of these periods and their capacity for predicting fruit size at harvest. The aim of this work was to evaluate the length of both periods in different cultivars and different location of full irrigated orchards. We also aimed to study the fruit feature impact on harvest at the end of Period I. Data from full irrigated olive orchards of cv Cornicabra, Arbequina and Manzanilla in two different locations (Ciudad Real, Central Spain, and Seville, South Spain) were used. The pattern of pit-breaking pressure throughout the season was measured with fruit samples for several years (2006 to 2022). These data and climatic data were used to compare different estimation methods for the length of Period I and II of endocarp development. Then, fruit volume and dry weight at the end of Period I were used to estimate fruit features at harvest. Results suggest that the Period I length was less temperature- and cultivar-dependent than expected. The duration of this period was almost constant at around 49 days after full bloom. Thermal time was negatively correlated with fruit size at the end of Period I. On the contrary, a lineal thermal model presented the lowest variability when estimating the Period II length, which was also affected by the cultivar. The best fit between fruit dry weight and volume at Period I vs. harvest was unique for oil cultivars (Cornicabra and Arbequina), while cv Manzanilla presented a different relationship. A temperature increase in the future would not affect the Period I length but would reduce the fruit size at the end of this period and at harvest. [ABSTRACT FROM AUTHOR]

Climate change and increased competition for water resources are generating growing concern about how to improve water-use efficiency in agriculture. In turn, this has prompted substantial investments in the installation of water-saving technologies in irrigation systems. The first aim of this research is to use data envelopment analysis to quantify, in terms of gross water savings (GWS), the local-scale efficiency of the irrigation policies adopted in an area of Spain suffering from a structural water deficit. Second, the cross-efficiency method is used to produce a ranking of the irrigation organizations analysed, in order to identify patterns of water-use efficiency performance that can guide future lines of investment. The results reveal that water-use efficiency prior to modernization is a key determinant of the efficiency achieved in terms of GWS at local scale. However, the investments targeted at irrigation modernization often have objectives other than water savings. These and other aspects should be taken into account when allocating public funds to irrigation modernization. [ABSTRACT FROM AUTHOR]

The need to feed an increasing population while limiting the environmental impact of agriculture is currently one of the greatest challenges relating to the food chain. One of the key factors involved in doing this is irrigation, which has a downstream impact that can be minimised if nutrient and water management are efficiently undertaken. The objective of this study was to determine which irrigation management improvements can be done at field scale in modern irrigated areas to reduce its irrigation return flow impact. The study was conducted in the Noguera Ribagorçana River basin, in NE Spain, where almost 6000 ha of land were brought into irrigation from 2000 to 2009. We based our study on a water quality dataset, measured in four different sites along a 29 km2 stretch of the river over a period of 20 years. Our results show an increase in nitrate (from 1.7 mg·L−1 to 10.5 mg·L−1) and salt concentrations (electrical conductivity from 297 to 675 µS·m−1) in the downstream course of the river compared to the most upstream monitoring site. That was exclusively associated with the irrigation return flows from the newly irrigated area. The highest nitrate and salt concentrations are found during the non-irrigation season which corresponds to the local rainy season. To reduce this impact, better irrigation management is required. Autumn leaching could be lowered by reducing irrigation volume applied during the final weeks of crop cycles in order to allow the soil to retain the volume of water received from rainfall. To deal with this issue, we propose a methodology based on soil moisture to determine the end of the irrigation season. In this way, the impact on ecosystems located further downstream would be reduced while crop yields and productivity in the area could be maintained. • Irrigation returns flows caused an increase in nitrate (1.7 mg·L−1 to 10.5 mg·L−1) and salinity in the river. • Irrigation in the studied area did not increase phosphorus concentration in the river. • Water quality in the river worsens during the non-irrigation months. • Reducing irrigation depths at the end of the season would lower the impact in the river. • A methodology based on soil moisture is proposed to reduce irrigation. [ABSTRACT FROM AUTHOR]

This paper discusses the gradual eclipse of a water management paradigm governed by the dominance of hydropower and irrigation-driven development. With the advent of new values, the former approach has given way to an acknowledgement of the value of water for its intangible contribution to the landscape, among other things. The European Water Framework Directive has lent further impetus to changes in water management and governance. Future water authorities and stakeholders will face additional management challenges such as growing water scarcity, climate change and the predominant role of regional governments in water use negotiation and decision-making. [ABSTRACT FROM AUTHOR]

Featured Application: This work demonstrates the feasibility of using wireless networks with Wi-Fi technology in the deployment of sensor networks for precision agriculture. The application of deficit irrigation techniques is essential in arid or semi-arid areas of the southeast of Spain, where water is a scarce and very costly resource. However, to apply these techniques, it is necessary to carry out preliminary tests on the specific crop in order to develop the models that allow the optimization of water use while achieving acceptable yields. The system proposed in this article demonstrates the feasibility of using wireless technologies available in most facilities (Wireless Fidelity) to deploy a high-density network of nodes with a variety of heterogeneous sensors to collect data from the soil, plant, and atmosphere. The data are sent and stored in a cloud server for real-time visualization from any mobile device and further analysis. The nodes have been developed using low-cost processors and are equipped with batteries and solar panels, allowing their autonomy to be virtually unlimited, as shown by the consumption studies and tests carried out. [ABSTRACT FROM AUTHOR]

Verticillium wilt, caused by the soil-borne fungus Verticillium dahliae, is one of the most harmful diseases in Mediterranean olive-growing areas. Although, the effects of both soil temperature and moisture on V. dahliae are well known, there is scant knowledge about what climatic drivers affect the occurrence of the pathogen on a large scale. Here, we investigate what climatic drivers determine V. dahliae occurrence in olive-growing areas in southern Spain. In order to bridge this gap in knowledge, a large-scale field survey was carried out to collect data on the occurrence of V. dahliae in 779 olive groves in Granada province. Forty models based on competing combinations of climatic variables were fitted and evaluated using information-theoretic methods. A model that included a multiplicative combination of seasonal and extreme climatic variables was found to be the most viable one. Isothermality and the seasonal distribution of precipitation were the most important variables influencing the occurrence of the pathogen. The isothermal effect was in turn modulated by the seasonality of rainfall, and this became less negative as seasonality increases. Thus, V. dahliae occurs more frequently in olive-growing areas where the day-night temperature oscillation is lower than the summer-winter one. We also found that irrigation reduced the influence of isothermality on occurrence. Our results demonstrate that long-term compound climatic factors rather than "primary" variables, such as annual trends, can better explain the spatial patterns of V. dahliae occurrence in Mediterranean, southern Spain. One important implication of our study is that appropriate irrigation management, when temperature oscillation approaches optimal conditions for V. dahliae to thrive, may reduce the appearance of symptoms in olive trees. [ABSTRACT FROM AUTHOR]

Irrigation and soil management can impact soil nitrous oxide (N2O) emissions. Flood and sprinkler irrigation systems together with conventional tillage are the main practices used in the high yielding maize systems in Mediterranean Spain. The objective of this field work was to quantify the effect of the irrigation system (i.e., flood, F; and sprinkler, S) and the soil tillage system (i.e., conventional tillage, CT; no‐tillage maintaining the maize stover, NTr; and no‐tillage removing the maize stover, NT) on the N2O emissions from the soil during 3 yr (2015, 2016, and 2017). S irrigation, with mean values of 1.35 kg N2O‐N ha−1 yr−1 throughout the 3 yr, obtained 42% lower N2O emissions than F irrigation. On average of the three growing seasons, yield‐scaled N2O emissions by grain yield and by grain N uptake in F irrigation were two‐fold higher than in S irrigation. Moreover, in one out of three growing seasons (2017), no‐tillage systems (i.e., NTr and NT) showed greater yield‐scaled N2O emissions compared with CT. The higher maize grain yield with the S irrigation compared to F irrigation, as well as the lower N2O emissions reported under S irrigation resulted in the reduction of the yield‐scaled N2O emissions. Our findings highlight the role of sprinkler irrigation decreasing N2O emissions in comparison to flood irrigation in Mediterranean agroecosystems. [ABSTRACT FROM AUTHOR]

• There is a clear relationship between the physiological and agronomical responses of almond to deficit-irrigation. • The cultivar effect is highly dependent on the irrigation water supply. • Guara and Lauranne offered similar yield results under water stress and over-irrigated situations. Almond (Prunus dulcis Mill.) has been traditionally associated to marginal areas in Andalusia, being cultivated under rainfed agriculture conditions. In the last few years, it has been progressively introduced in many irrigated areas of the Guadalquivir river basin which has promoted a growing interest about irrigation water management for this crop i. e. the potential irrigation requirements, or the best irrigation strategy under sub-optimal conditions (aiming at obtaining balanced nut yields, saving water without affecting yield). This work examines the response of three almond cultivars (cvs. Guara, Marta and Lauranne) subjected to different irrigation regimes in a semi-arid Mediterranean environment (SW Spain). The trial was conducted over two seasons (2017–2018), in a commercial orchard with three irrigation regimes: i) a full-irrigation treatment (F I), which received 100% of crop evapotranspiration (ET C) as a control; ii) an over irrigated treatment (150-ET C), which received 150% of ET C during the whole irrigation period; and iii) a regulated deficit irrigation treatment (RDI 65) which was irrigated at 100% ET C during the whole irrigation season, except during the kernel-filling period, when it received the 65% of ET C. In order to assess the crop water status, the leaf water potential (Ψ leaf) and the stomatal conductance to water vapour (g s) were measured. At the end of each season, the yield, kernel unit weight and irrigation water productivity were determined. Significant differences in physiological behaviour and yield responses among cultivars were found. According to the final yield obtained during the experimental seasons, Guara and Lauranne did not show significant improvements in the 150-ET C in relation to F I and RDI 65 , whereas cv. Marta showed significant improvements under 150-ET C. Moreover, yield response followed the physiological trend observed in the different irrigation treatments for each cultivar. Those cultivars (Guara and Lauranne) that had not shown significant differences in terms of yield, evidenced a similar pattern in terms of g s , unlike Marta. The obtained results allow us to conclude that there is a clear differential response in terms of the cultivar, taking into account the adaptation capacity of different cultivars to different irrigation doses. [ABSTRACT FROM AUTHOR]

• Soil GHG emissions were measured during two years in irrigated maize. • Irrigation frequency had a minor impact on GHG emissions. • Nighttime irrigation increased soil N 2 O emissions. • Nighttime irrigation enhanced maize grain yield by 13%. • N 2 O scaled emissions was not affected by the irrigation management. Irrigation management may influence soil greenhouse gas emissions (GHG). Solid-set sprinkler irrigation systems allow to modify the irrigation time and frequency. The objective of this study was to quantify the effect of two irrigation times (daytime, D; nighttime, N) and two irrigation frequencies (low, L; high, H) on soil carbon dioxide (CO 2), methane (CH 4), and nitrous oxide (N 2 O) emissions in a solid-set sprinkler-irrigated maize (Zea mays L.) field located in NE Spain during 2015 and 2016 growing seasons and the fallow period between growing seasons. Compared with D irrigation, N irrigation increased soil water content (0–5 cm) in both growing seasons. Irrigation management did not affect CH 4 emissions and the soil acted as a sink of CH 4. Cumulative CO 2 emissions were affected by the measurement period (growing season vs fallow) with the greatest values in 2015 growing season, being 81 and 32% higher over the fallow period and over the 2016 growing season, respectively, due to the effect of the preceding crop, alfalfa, and a better soil moisture conditions for the microorganism activity. Similarly, cumulative N 2 O emissions showed the highest values in 2015, reporting values 90 and 51% greater than the fallow period and the 2016 growing season, respectively. Moreover, N irrigation increased cumulative N 2 O emissions by 29% compared with D irrigation, but irrigation frequency did not affect cumulative N 2 O emissions. Irrigation time did not affect cumulative N 2 O emissions scaled per grain yield or per N uptake because N irrigation increased maize yield by 11% compared with D irrigation. Due to the lack of differences in the scaled N 2 O emissions, N irrigation should be consider as an appropriate strategy to optimize grain yield without compromising soil GHG emissions per unit of grain yield in Mediterranean agroecosystems. [ABSTRACT FROM AUTHOR]

• Reclaimed water alleviates agricultural water scarcity all around the year. • Reclaimed water may supply a large part of the crop nutrient requirements. • No sodicity risk has been observed for most of the reclaimed waters. • High salinity of the reclaimed water has led to considerable yield reductions. • Appropriate irrigation and soil management strategies are strongly recommended. Reclaimed water (RW) can alleviate agricultural water scarcity all around the year with the quality factor, but its use is often questioned by farmers due to agronomic concerns. In this study, we selected three areas and five different representative crops (muskmelon, lettuce, lemon, peach and tomato) in the southeast of Spain to study the impact of the irrigation with RW on (i) the supply of essential nutrients, (ii) the effect of water salinity on the crop yield, (iii) the crop toxicity to Cl−, Na and B ions, (iv) the soil sodicity risk and (v) the economic inflow-outflow analysis. The results evidenced that RW could supply a large part of the crop nutrient requirements, particularly in the selected woody crops, although temporal mismatches between crop nutrient requirements and nutrients in the water supplies should be considered when preparing fertigation plan. The electrical conductivity (EC w) of the RWs could lead to yield reductions from 0% in muskmelon to 23.2% in peach. Despite this, only chlorosis risk in lemon and peach and toxicity effects of Na and B in lemon trees could be envisaged. In addition, soil sodicity risks were low for most of the RWs. The economic inflow-outflow balance justified the fertigation with RW in muskmelon, lettuce and lemon. However, for peach and tomato, despite the economic savings associated to the fertigation, the high yield reduction due to the EC w made less viable the irrigation with RW. Overall, the study shows that fertigation accounting for RW nutrients can substantially save fertilizers costs while agronomical risks, when present, can be controlled with irrigation management strategies for several crops in SE Spain. [ABSTRACT FROM AUTHOR]

Intensive irrigated agriculture substantially modifies the hydrological cycle and often has major environmental impacts. The article focuses upon a specific concern—the tendency for progressive long-term increases in the salinity of groundwater recharge derived from irrigated permeable soils and replenishment of unconfined aquifers in more arid regions. This process has received only scant attention in the water-resource literature and has not been considered by agricultural science. This work makes an original contribution by analysing, from scientific principles, how the salinisation of groundwater recharge arises and identifies the factors affecting its severity. If not proactively managed, the process eventually will impact irrigation waterwell salinity, the productivity of agriculture itself, and can even lead to land abandonment. The types of management measure required for mitigation are discussed through three detailed case histories of areas with high-value groundwater-irrigated agriculture (in Spain, Argentina and Pakistan), which provide a long-term perspective on the evolution of the problem over various decades. [ABSTRACT FROM AUTHOR]

The knowledge of the soil variability is essential for its hydrologic characterization, for irrigation management and planning and especially for water movement modeling. Nevertheless, the scarcity of soil information in Spain precludes its use in irrigation management and, particularly, in the on-going irrigation modernization process. The Violada Irrigation District (VID) comprises 5234 ha and is located in a semi-arid gypsum-rich region in northeast Spain. VID has been under flood irrigation since the mid-20th Century and has been modernized recently to sprinkler irrigation. Since the early 1980s water balances in VID have been based on average soil properties and bulk irrigation data. The current irrigation system provides detailed irrigation data at plot level, thus allowing for performing distributed balances (in hydrologic homogenous zones) that require detailed or semi-detailed soil information in the form of a soil map. The objective of this two-part study is to define homogeneous zones in relation to hydrological properties relevant for irrigation management, first defining the soil variability within the VID and then analyzing the soils hydrologic and salinity features (in a companion paper). The specific objectives of this paper were (i) to draw the VID semi-detailed soil map; (ii) to explain the variability of soil properties; and (iii) to map the main soil characteristics related to irrigation management. Thirty four soil pits, located on all the different geomorphological areas, were opened and described. Samples were taken from all the horizons and analyzed for chemical and physical properties. The limits of soil units were drawn with the aid of 32 additional auger holes, the data from 72 pits opened during the irrigation transformation works, and all the previous soil information available. Finally the soils were classified down to family level. The main soil formation processes in VID were carbonation and gypsification. Thirteen soil units were defined, included in five soil subgroups and six particle size families. “Fine” particle sizes were dominant along the gypsum-rich valley bottoms. Coarser textures were found on the heights and showed higher CaCO 3 equivalent content and no presence of gypsum accumulations. A priori, the main limitation for irrigation in the valley soils was the limited drainage (due to fine textures and reduced slope) while in the highland soils it might be constrained by their low retention capacity. The high gypsum and carbonate content of the VID soils may prevent the development of infiltration problems. The soil properties map in this work will be the basis for a companion paper delineating the hydrologic properties of the soils, the basis for improved soil water balances. [ABSTRACT FROM AUTHOR]

Irrigation plays a very important role in a Mediterranean garden. In spite of this, there are not many studies assessing irrigation water management of landscapes. Moreover, historic gardens represent a special challenge due to their unique characteristics. The aim of this work is the characterization and evaluation of water management in a historic garden. For that, the gardens of The Real Alcazar of Seville were used as a case study. They comprise a total of 20 gardens of different styles with a total area of nearly 7 ha. Landscape water requirements and irrigation volume applied were estimated and used in conjunction with other descriptive and financial variables to calculate 6 performance indicators. Only 20% of gardens showed adequate irrigation in the spring-autumn period, being 10% during summer. However, the two well-watered gardens represent 30% of the total irrigated area. Management, operation and maintenance costs are 0.63 €·m −2 representing 0.58 € per volume of irrigation water used (m −3 ). Results obtained support the need of improving irrigation management. For that, simple solutions such as installing metering devices, calculating actual water requirements or optimizing irrigation schedules can be implemented. Other more complex actions such as modifying the irrigation network or creating hydrozones might also be explored. [ABSTRACT FROM AUTHOR]

This work focuses on the transformation occurred with the shift from surface to drip irrigation, looking at three collective irrigation systems in Valencia (Spain). The extension of drip irrigation over areas previously irrigated by systems of gravity channels entails a process of change and transformation of institutions and organizations managing irrigation. We analyze the main management changes occurred and how farmers adapt to the new technology. In order to assess these changes, interviews were conducted with farmers and managers of Water User Associations. Drip irrigation implementation policies result in unforeseen consequences, paradoxes and challenges for collective drip irrigation management. In the three cases, drip irrigation and automation has contributed to the centralization of decision-making. Besides, farmers and managers have also developed irrigation and fertigation strategies to adapt to the new technology. When some of these new operating procedures are applied, farmers obtain results closer to their own goals, but not necessarily linked to the virtues frequently attributed to drip systems. [ABSTRACT FROM AUTHOR]

This article presents a method for analyzing the economic feasibility of modernizing irrigation systems. By using substitution relationships between two variables, one can determine irrigation performance and farm profit ​above which modernization would be justified from an economic point of view; ​and also the  investments and energy consumption up to which modernization could be considered cost-effective. By means of representative average values, this method is applied to the now widespread conversion from surface irrigation to drip irrigation in Spain. Two conclusions are drawn. First, modernization may, in some instances, be justified only if more productive crop patterns are implemented. Second, saving water is a cheaper option than using an alternative resource only under certain conditions. [ABSTRACT FROM PUBLISHER]

Improving irrigation management is of relevant importance to ensure a sustainable use of resources in water-scarce areas. Among the actors involved in water management, irrigation communities (ICs) are key players. This work aims to identify which ICs attributes explain the observed variability in performance indicators (PI). To this end, panel data regression models have been applied using a 9-year data set of different indicators from five ICs in the Segura River Basin, south-east Spain. Our study indicates that a limited number of IC attributes-amount of supplied water, water delivery infrastructure, use of groundwater, water allocation method, size and price paid for energy of the IC-explain most of the variability of the PI considered in the study. From this PI approach, it appears that the evaluated ICs should preferably use an on-demand water allocation method, adopt size growing policies and collective action for energy purchase to obtain economies of scale and higher security in water provision to farms, and also to update irrigation systems. Furthermore, water distribution systems that require high energy demand should be used only when they permit to reduce irregularity and risks of shortage in water supply. [ABSTRACT FROM AUTHOR]

Irrigated areas face new, pressing challenges due to escalating energy costs for pumping, increasing cost of seeds, fertilizers and agrochemicals, volatility of agricultural commodities, pressure of environmental regulations, water scarcity and mounting cost of irrigation infrastructure investments. At the same time, from the technical standpoint, farmers can chose from a wide array of irrigation design and operation alternatives for collective and on-farm systems, with variable effects on crop yield and profitability. These factors are often subjected to quick changes, complicating decision making. Simulation models have proven useful to support decision making in irrigation infrastructure, water / energy use, crop agronomy and soil management. In this research, new capacities of the Ador-Simulation software are reported, targeting comprehensive analyses of irrigation modernization. The model implements additional on-farm irrigation methods (low-pressure solid-set, center-pivot and drip irrigation); crop intensification (double cropping in the same season); and crop response to different on-farm irrigation management options (timing and frequency). Model performance was verified using a set of theoretical case studies. Finally, the model was applied to the optimization of irrigation design and management (water and energy) in the Bardenas XI project of northeastern Spain. Water application in center-pivot and drip irrigation were simulated using a normal distribution characterized by a user-defined Distribution Uniformity. In center-pivot, the application depth was randomized in every irrigation event, reproducing the random nature of wind disturbances. In drip irrigation, the application depth followed the same random distribution in all irrigation events, reproducing the deterministic effect of manufacturing and hydraulic variability. According to the literature, the effect of irrigation timing was treated differently for two key sprinkler irrigated crops: corn and alfalfa. Differences in water application and crop yield between on-farm methods resulted in different gross and net income. In the Bardenas XI project, irrigation performance indicators showed different patterns of inter-annual variability. Deep percolation was strongly affected by the amount of seasonal precipitation and by Distribution Uniformity. Indicators at the plot level were strongly determined by the on-farm irrigation method, the soil type, and the crop. In the conditions of Bardenas XI, the design option without pumping station was the most adequate. Natural pressure proved sufficient for a combination of low-pressure sprinkler irrigation, pivot and drip irrigation methods, distributed throughout the irrigated area. Escalating energy costs emphasize the need for careful assessment of pumping requirements at the design phase of irrigation projects. • Pivot and drip irrigation methods have been successfully incorporated in the simulation tool. • On-farm irrigation method has an important effect on irrigation performance indicators. • Performance indicators are also determined by the soil type and the crop. • The effect of seasonal DU lq and precipitation on deep percolation is remarkable. • Pumping and energy needs should be carefully evaluated at the irrigation design phase. [ABSTRACT FROM AUTHOR]

In the old-world viticulture, there is a common but most often not scientifically proven consideration that supplemental irrigation should detrimentally affect berry and wine composition. In the temperate-warm climate of inland Valencia (Spain), during three growing seasons (2009–2011), the effects of post-veraison deficit irrigation regime on Cabernet Sauvignon vine performance and berry composition were determined. Rainfed vines were compared with three post-veraison deficit irrigation regimes replacing 25, 50 and 75% of the estimated crop evapotranspiration, resulting in water application of 37, 67 and 128 mm, respectively. Rainfed vines experienced quite severe plant water stress, reaching, in two out of the three experimental seasons, midday stem water potential values as low as −1.6 MPa. Despite this, rainfed vines at harvest had the highest concentration of berry total soluble solids and phenolics among all tested water regimes. This was most likely a consequence of berry dehydration which, in the rainfed vines, resulted in a reduction of berry size, while in the irrigated treatments a constant increase in fresh berry weight was observed during the ripening period. As a consequence, the two greater irrigated treatments resulted in a 26–30% yield increase. In addition, when replacing half of the potential water needs, total water use efficiency could be maintained at similar levels as in rainfed vines. In any case, the main positive effect of the supplemental irrigation application was to avoid the excessive increase in berry sugar content, which at commercial vintage time reached up to 16.5% of probable alcohol in the rainfed treatment. It is therefore concluded that moderate post-veraison irrigation water application might result in a more balanced sugars-phenolics grape composition while considerably increasing yield in comparison with the rainfed regime. In any case, the most convenient irrigation strategy might depend on the desired grape style and, indeed, on wine consumer preferences [ABSTRACT FROM AUTHOR]

Copyright of Historia Agraria is the property of Historia Agraria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Historia Agraria is the property of Historia Agraria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In semi-arid regions, aquifers provide a series of practical advantages that make them preferential sources of water supply. In Spain, groundwater meets about one-fifth of the total water demand and is used to irrigate over one-third of the total irrigated land. This article examines groundwater use in Spain from the perspective of the EU Water Framework Directive. Analysis of different sector uses suggests that core problems (and solutions) related to groundwater lie in agricultural uses and that the Directive's environmental requirements remain distant from reality on the ground, where economic, political and social reasons prevail on legal obligations set by national and supranational authorities. [ABSTRACT FROM AUTHOR]

The author discusses topics related to irrigation management for strawberry production in south-west Spain. He mentions about high dependency of strawberry cultivation on fresh water, which leads to concerns regarding environment sustainability of the cultivation, and further discusses use of low-density polyethylene tapes as irrigation emitters for the cultivation. Also discussed is an irrigation system that ensure uniform application of water.

The digitalization of the agricultural sector through the implementation of cutting-edge technologies allows for the optimization of the use of water, whose scarcity has become one of the most relevant and complex environmental global problems. Water consumption data collected on site using different technologies is key to achieving optimal irrigation scheduling. Technology is also a useful tool that provides a real and transparent inventory of water use in irrigated crops. The water footprint obtained in accordance with ISO standard 14046 (using the Life Cycle Analysis methodology) and jointly with irrigation management information allows determining water use efficiency with great accuracy. This work presents a decision support system developed for precision irrigation management at farm scale called DSSPIM. The system provides a verifiable inventory of water use and an analysis/diagnosis of the adequacy of the irrigation performed using information and communication technologies (ICTs), as well as real-time knowledge of water inputs and outputs during crop development based on data received from water meters and soil moisture sensors installed in the field. Additionally, to achieve both purposes, a methodology is proposed to more accurately estimate rainwater use (green water) based on real measurements and the use of ICTs. The proposed methodology was applied during one season in two organic crops (greenhouse tomatoes and orange trees) located in southern Spain. The model allowed detecting inefficiencies in irrigation water use. A comparison between the actual management practices and the practices recommended by the DSSPIM underlines the importance of irrigation management in improving water use. In the case of orange trees, different irrigation system management scenarios were compared and showed that the application of controlled deficit irrigation strategies using DSSPIM can reduce irrigation water use by 20%. • The model performs optimal irrigation scheduling and evaluates water use efficiency. • Tool for outdoor woody and greenhouse horticultural crops with drip irrigation. • Data from moisture sensors are used to determine soil water deficit. • Water use efficiency is evaluated by WF C , RIS and irrigation scheduling analysis. [ABSTRACT FROM AUTHOR]

Abstract: Pressurized irrigation networks require large amounts of energy for their operation which are linked to significant greenhouse gas (GHG) emissions. In recent years, several management strategies have been developed to reduce energy consumption in the agricultural sector. One strategy is the reduction of the water supplied for irrigation but implies a reduction in crop yields and farmer's profits. In this work, a new methodology is developed for sustainable management of irrigation networks considering environmental and economic criteria. The multiobjective non-dominated Sorting Genetic Algorithm (NSGA II) has been selected to obtain the optimum irrigation pattern that would reduce GHG emissions and increase profits. This methodology has been applied to Bembézar Margen Derecha (BMD) irrigation district (Spain). Irrigation patterns that reduce GHG emissions or increase actual profits are obtained. The best irritation pattern reduces the current GHG emissions in 8.56% with increases the actual profits in 14.56%. Thus, these results confirm that simultaneous improvements in environmental and economic factors are possible. [Copyright &y& Elsevier]

The effect on productive and vegetative behavior and on the quality of oil from Olea europaea L. when applying two distinct irrigation techniques, full irrigation (FI) and regulated deficit irrigation (RDI), was studied. A total of five wet soil volumes (WSVs, 12, 24, 35, 47 and 59%) expressed in terms of the potential root exploration volume were established for each strategy. The experiment was performed on cv. 'Arbequina' in an olive grove in Tarragona (Spain). Results obtained suggest that a 20% reduction in the irrigation dose (RDI) had no significant effect either on olive fruit and oil production or on oil content. Likewise, no significant increase in irrigation water-use efficiency was observed for FI with respect to RDI. A tendency for olive and oil production per hectare to increase with increased WSV percentage was observed, although there were no significant differences between FI and RDI except for 59% WSV in the RDI strategy, producing the best response. [ABSTRACT FROM AUTHOR]

Abstract: This paper examines irrigation water management in the Genil-Cabra Irrigation District of the Province of Cordoba (southern Spain) using three irrigation indicators: relative irrigation supply (RIS), relative water supply (RWS), and relative rainfall supply (RRS). The three indicators are calculated both globally and by grouping the data according to crop type, irrigation method, soil texture, and plot size. Then, it is possible to determine the influence that each individual factor has on irrigation management and take subsequent measures to improve irrigation performance. All of the information regarding agronomic and hydraulic variables has been included in a geographical information system (GIS) to facilitate data management. The results show that irrigation is deficit given that the mean value of the RIS indicator is relatively low, around 0.60. However, the RWS indicator achieves higher mean values, normally above 0.80, indicating that evaporation demand can be met throughout the crop development cycle. The RRS indicator shows less variability with mean values around 0.40. This indicator, together with the RWS indicator permits the evapotranspiration fraction covered by rainfall to be determined. The mean values of the calculated indicators are very useful for gaining a better understanding of irrigator behavior and general irrigation trends, although the study sample is still insufficient to characterize a large irrigation area as a whole. [Copyright &y& Elsevier]

Abstract: Nitrogen (N) pollution induced by irrigated agriculture is a significant environmental problem. The main N inputs and outputs were measured or estimated in the semi-arid La Violada irrigation district (Spain). Data on two periods (1995–1998 and 2006–2008) were compared and related to observed changes during the decade in cropping patterns and N fertilization and irrigation management. N fertilization exceeded crop N uptake due to over-fertilization of corn (426kgN/ha in 1995–1998 and 332kgN/ha in 2006–2008) and alfalfa (62kgN/ha). Between the two periods, N fertilization decreased by 56%, primarily due to a change from corn to alfalfa and barley. Accordingly, N losses in the irrigation return flows (IRF) diminished from 31% of the applied fertilizer in 1995–1998 to 20% in 2006–2008. NO3 − concentrations and NO3-N loads in the IRF decreased from 40mg/L and 106kgN/ha in 1995–1998 to 21mg/L and 22kgN/ha in 2006–2008, due to lower N fertilization, lower corn area and improved irrigation efficiency. N contamination in the IRF will be minimized by increasing the irrigation efficiency and decreasing the corn area and its N fertilization rates, particularly when supplemental organic N is applied at pre-sowing. [Copyright &y& Elsevier]

Abstract: Irrigation district salt balances identify the main sources and sinks of salts and quantify salt loads in irrigation return flows. Salt balances were performed in La Violada Irrigation District during the 80s (1982–1984), 90s (1995–1998) and 00s (2006–2008) decades. Total Dissolved Solids (TDS) and loads in irrigation return flows were related with changes in irrigation performance and infrastructures during these decades. TDS increased linearly to increases in Irrigation Consumptive Use Coefficient (ICUC) (P <0.01), and decreased with increases in Drainage Fraction (DRF) (P <0.001). The salt balances revealed that 82% of the exported salts originated from soil gypsum dissolution. Annual salt yields in return flows were high and similar in the 80s and 90s (about 19.3Mg/ha year), and halved in the 00s (9.9Mg/ha year) due to comparable reductions in irrigation and drainage volumes derived from a better irrigation performance. Irrigation season salt yields were high and steady around 14.1Mg/ha for ICUC<51% and DRF>66%, and decreased exponentially for values above and below these thresholds, respectively. Therefore, the key management strategy to reduce salt discharge to downstream areas is to decrease drainage volumes by improving irrigation management. [Copyright &y& Elsevier]

Abstract: Irrigated agriculture notably increases crop productivity, but the generated irrigation return flows may induce surface water pollution by nutrients if irrigation water and fertilization management are inadequate. In this study, the Del Reguero watershed (Huesca, Spain) was characterized, and irrigation performance was assessed to identify sprinkler irrigation water management impact on surface and subsurface water losses during the 2008 and 2009 hydrological years. Farmers were interviewed, and soil and water use surveys were performed. The main water inputs and outputs of the system were measured (irrigation, precipitation, filter cleaning, and outflow surface drainage) or estimated (municipal waste waters, actual evapotranspiration, wind drift losses, and evaporation losses) and the evaluation of the irrigation performance was performed using various water management indexes. Thirty-two percent of the area contained platform soils or cambisols characterized by a small depth, high stoniness, and limited value of total available water. The main cultivated crops were corn, barley, alfalfa, and sunflower, occupying more than 83% of the irrigated area. The annual average water inputs were 3.1% higher than water outputs. However, the error balance is considered acceptable and its resulted inputs and outputs parameters values can be used to calculate nutrients mass balance. The annual average irrigation efficiency was low (72%), due to the fact that alfalfa and corn were inadequately irrigated. The average annual consumptive water use efficiency was high (91%), indicating that a high percentage of available water was destined for crop evapotranspiration. However, irrigation management was inadequate because there was an annual average water deficit of 9%, indicating that not all the water requirements of crops were met. This high deficit was justified by the reduced irrigation allocation received by sunflower and barley. These two crops were under-irrigated by 90 and 168mm below their respective net irrigation requirements. At a watershed scale, the average annual seasonal irrigation performance index (SIPI) was 87%, which could indicate that all crops were water satisfied. However, the calculation of SIPI at field scale, revealed that alfalfa and corn were water satisfied (SIPI=81% and 78%, respectively) and that barley and sunflower were water stressed (SIPI=132% and 200%, respectively). [Copyright &y& Elsevier]

Abstract: In an earlier study, irrigation water use in the Del Reguero watershed (DRW) was assessed using various water management indices. In this study, the phosphorus (P) transport dynamics in the irrigation return flows were analyzed. Phosphorus fertilization practices were determined through interviewing farmers, and P loads were monitored from October 2007 to September 2009. In surface drainage waters, the average annual total phosphorus concentration (TP) was 0.112mgL−1. Total dissolved P (TDP) represented the dominant P form (93% of the TP concentrations) indicating that subsurface flow was the dominant pathway for P transfer. Drainage water was classified as hypertrophic during 2008 and eutrophic during 2009. Fertilizer contributed the most to the final result of P mass balance by contributing 98% of the total P inputs. P crop needs were exceeded by 16% leading to an excess of 43.8kgPha−1 year−1. The exported mass of P was 240kg in 2008 and 228kg in 2009, and the TP loss was 205gPha−1 for 2008 and 195gPha−1 for 2009. The amount of TP load in the Del Reguero stream was considered small with regard to total phosphorus input (0.23%). However, the amount of TP load in the Del Reguero stream was considered significant in regard to surface water eutrophication. Because the majority of the TP load existed in the dissolved form (TDP=93% of TP), a large portion of the P losses from the system was available for algae growth, thereby, enhancing eutrophication. [Copyright &y& Elsevier]

Abstract: The creation of a new irrigated area influences the pollutants exported from the zone and, consequently, the quality of receiving water bodies. The aim of this study was to analyze the masses of the main pollutants exported by an area before and during its gradual transformation into irrigated land. To this end, salinity balances were carried out and the nitrate exported from the Lerma basin (752ha, Spain) was quantified during 2004–2008. The agroenvironmental impact was evaluated through the use of pollution indices. The results revealed that the transformation of the area into irrigated land decreased salinity and increased nitrate concentration in drainage. The increase in the volume of drainage increased the masses of salt and nitrate exported, which in turn increased pollution indices during the transition. However, these indices were still lower than those quantified in other irrigated lands and therefore can still be considered to be of low contamination level. This study demonstrates the important environmental influence of introducing irrigation to an area, as pollution levels change and become mainly dependent on the management of irrigation and nitrogenous fertilization. For this reason, it is highly desirable to promote the optimization of agricultural management in a way that minimizes its impact. [Copyright &y& Elsevier]

Abstract: The growing necessity to develop more productive agriculture has encouraged the expansion of new irrigated lands. However, water use in agriculture may affect the natural regimes of water systems. This study aims to analyze, for the first time, water use and its dynamics during the creation of a newly irrigated land. Water use was studied through the development of water balances and subsequent application of quality indices for irrigation in two unirrigated years (2004–2005) and three years of gradual implementation of irrigation (2006, 2007 and 2008) in the Lerma basin (752ha, Spain). Increases in evapotranspiration, drainage and water content in the aquifer were verified during the gradual transformation into irrigated land. Water balances closed adequately, giving consistency to the results and enabling the application of quality indices for irrigation. Irrigation quality analysis showed a use of available water resources equal to 84%. However, the estimated irrigation efficiency presented lower values, mainly due to irrigation drainage (15%) and combined losses by both evaporation and wind drift of sprinkler irrigation systems (13%). The results indicate that the use of water in the Lerma basin is at the same management level of other modern irrigation systems in the Ebro basin, although there is still margin for improvement in irrigation management, such as reducing the irrigation drainage fraction and the evaporation and wind drift losses of sprinkler irrigation systems. [Copyright &y& Elsevier]

Abstract: The analysis of long-term irrigation performance series is a valuable tool to improve irrigation management and efficiency. This work focuses in the assessment of irrigation performance indices along years 1995–2008, and the cause–effect relationships with irrigation modernization works taking place in the 4000ha surface-irrigated La Violada Irrigation District (VID). Irrigation management was poor, as shown by the low mean seasonal irrigation consumptive use coefficient (ICUC=51%) and the high relative water deficit (RWD=20%) and drainage fraction (DRF=54%). April had the poorest irrigation performance because corn (with low water demand in this month) was irrigated to promote its emergence, whereas winter grains (with high water demands in this month) were not fully irrigated in water-scarce years. Corn, highly sensitive to water stress, was the crop with best irrigation performance because it was preferentially irrigated to minimize yield losses. The construction of a new elevated canal that decreased seepage and drainage fractions, the entrance in operation of six internal reservoirs that would increase irrigation scheduling flexibility, and the on-going transformation from surface to sprinkler irrigation systems are critical changes in VID that should lead to improved ICUC, lower RWD and lower DRF. The implications of these modernization works on the conservation of water quantity and quality within and outside VID is further discussed. [Copyright &y& Elsevier]

The spatial variability of the wind in the Montesnegros Irrigation District (MID), in Spain, has been analysed. From a wind series (2004–2007) registered by a reference weather station, a windspeed >2ms−1 was observed about 50% of the time. During these periods about 70% of the time it blew from the northwest (known as the Cierzo). Wind was monitored at the reference site and at 17 sites throughout the MID. Using regression a series of the local wind velocities for the irrigation seasons 2004–2007 were estimated from the reference station data. Wind exposure for 39% of the MID area was found to be similar to that of the reference site; 25% were less exposed and 36% considerably more exposed. The spatial variability of the wind was used to calculate the suitable time for irrigation (STI, %) using Ador-Sprinkler software. STI was simulated for different irrigation systems and strategies: standard – Christiansen’s uniformity coefficient (CUC)>84% and wind drift and evaporation losses (WDEL)≤20%, restrictive –CUC ≥90% and WDEL ≤15% and relaxed – CUC >80% and WDEL ≤25%. At the reference site, STI varied from 50 to 56% of the total time during the irrigation season time for standard strategy, from 68 to 77% for the relaxed strategy and 8 to 30% for the restrictive strategy. Excluding the restrictive strategy, the least exposed sites averaged 14% greater STI than the most exposed sites. [ABSTRACT FROM AUTHOR]

The article analyzes the work of political economist Elinor Ostrom, specifically discussing her book "Governing the Commons." The author evaluates Ostrom's study, which revolved around a large sample of collective action institutions created to regulate the use of common property resources, including Spanish orchards in areas of Valencia, Murcia and Alicante. Ostrom's conclusion that the successful institutions used the same eight design principles, such as clearly defined boundaries, appropriation rules and collective-choice arrangements, is assessed. The author of the article determines that those principles were not always present in the studied orchards, and argues that some of Ostrom's theoretical instruments in analyzing irrigation institutions become less effective in this light.

Expansionist policies in irrigation in Andalusia have led to an intensive use of water, which has depleted rivers and aquifers and led to high added costs in terms of hidden subsidies for irrigation farming. Water scarcity has become an increasing social and economic worry for those responsible for regulating water policies and has created problems among users, especially when it is an important factor for production purposes. This empirical study analyses the differences that exist in terms of economic efficiency in the 156 irrigation areas of Andalusia. To achieve rational management of irrigation water it is essential to consider economic efficiency and carry out comparative studies to identify the causes that contribute to differences in terms of efficiency. This paper describes the conclusions of a study into economic rationality in the use of such a scarce resource as water. [ABSTRACT FROM AUTHOR]

Irrigation water management in the Genil-Cabra irrigation district, located in the province of Cordoba, Southern Spain, was studied using three irrigation performance indicators: relative irrigation supply (RIS); relative water supply (RWS) and relative rainfall supply (RRS). All indicators have been calculated as in a global way as grouping data according to crop type, irrigation method, soil texture, and size irrigation plots. All information of agronomic and hydraulic variables was incorporated in a Geographic Information System (GIS) to ease its management. Results show that applied irrigations are deficit irrigations because RIS values are relatively low. However, RWS values are greater and evaporative demand may be satisfied along crop development cycle. RRS indicator varies less that the other two and, together with RWS, permits to know the evapotranspiration fraction covers by rain water. The mean values of performance indicators we have calculated are very useful to know farmer's behaviour and the general trend, although the used sample is not significant to characterize the global irrigation district. [ABSTRACT FROM AUTHOR]

This paper presents a novel approach to assess spatial and temporal irrigation performance in urban parks and can assist park manager/operator decisions in irrigation management. First, irrigation needs are estimated by traditional irrigation scheduling and the irrigation zones with similar water needs that share the same electric valve (hydrozones) are identified. Then, irrigation performance is calculated using the relative water supply (RWS) indicator and mapped (GIS software). This approach can be adapted to various spatial and temporal scales. In this study, it was applied to the Valdebebas urban development VBB (Madrid) between the 2017 and 2019 irrigation seasons. The results for the VBB parks showed high spatio-temporal variation in irrigation performance among plant typologies within an irrigation season, which can be explained by the landscape coefficient KL variation across the parks. Likewise, this variation was also observed among the three evaluated seasons; explained among other factors by differences in irrigation management. For each hydrozone, the estimation of the NDVI index by Sentinel-2A satellite images in 2019 showed a threshold on irrigation performance. Thus, the remote sensing data together with the proposed approach can be a valuable tool for helping park managers/technicians adopt better decisions on irrigation practices. [ABSTRACT FROM AUTHOR]

Over the last three decades, a great investment effort has been made in the modernization of irrigation in the Valencian Community (Spain). The initial change from distribution networks to pressurized ones and the shift towards drip irrigation systems was followed by improvements in irrigation scheduling, based on agrometeorological data, soil water content sensors, and remote sensing. These improvements are considered adequate for increasing irrigation water use efficiency, but it is difficult to find systematic measurements to assess its impacts on irrigation adequacy along with irrigation productivity in fruit orchards. This work presents the results of a four year assessment of irrigation water and energy use efficiency along with water productivity of a recently established irrigation community in the province of Valencia (Spain). The study was carried out at the orchard level and focused on two fruit crops: persimmon and peach trees. Six irrigation performance indicators, relative water supply (RWS), relative irrigation supply (RIS), yield performance (Yp), global water productivity (WPoverall), output per unit irrigation water (OUI), and the percent of nitrogen fertilization obtained by irrigation water, were defined and calculated for years 2017 to 2020 in 104 persimmon and peach orchards. The results showed that most of the farmers irrigated below the crop water requirements, showing RWS and RIS values less than 1, and there was great variability among farmers, especially in WPoverall and OUI indicators. [ABSTRACT FROM AUTHOR]

• The short-term impact of stover management and its interaction with irrigation on soil organic carbon changes was evaluated. • Stover management resulted in significant differences in soil organic carbon and particulate organic matter carbon. • After 4 years, soil organic carbon change was not affected by the interaction between stover management and irrigation. In croplands, the adoption of certain management practices may increase soil organic carbon (SOC) levels. In this study, we evaluated the short-term impact of crop stover management and the interaction between crop stover and irrigation method on SOC change in a continuous maize (Zea mays L.) system in Spain. Four years after the beginning of the experiment, total SOC and C fractions (particulate organic matter carbon, POM-C; and mineral-associated organic matter carbon, Min-C) contents, SOC stocks and SOC stock changes were measured in four different soil layers (0−5, 5−10, 10−25 and 25−50 cm) in an experiment with two irrigation methods (sprinkler and flood) and three stover management systems (conventional tillage with all the stover incorporated, CT; no-tillage maintaining the stover, NTr; and no-tillage removing the stover, NT). Stover management resulted in significant differences in SOC and POM-C but not in Min-C. In particular, NT reduced SOC and POM-C contents compared with CT and NTr (about 10 and 60 %, respectively). After 4 years, SOC change was not affected by the interaction between stover management and irrigation. Concurrently, both CT and NT showed SOC losses, reaching 0.11 and 1.22 Mg ha−1 yr−1 in CT and NT, respectively. However, NTr showed SOC gains at a rate of 0.09 Mg ha−1 yr−1. Consequently, the removal of crop stover has been demonstrated as a detrimental strategy to store SOC in the short-term in irrigated continuous maize systems. [ABSTRACT FROM AUTHOR]

In Spain, water use in agriculture is expected to become limited by resources in the future. It is pertinent to study the effect of decreased irrigation on the presence of pests, plant damage, and arthropod communities in a super-intensive olive orchard examined from 2017 to 2019. Arthropods were studied with visual and vacuum sampling methods in two irrigation treatments (T1—control and T2—Regulated Deficit Irrigation (RDI)). Univariate analyses showed that the total arthropod abundance was significantly greater in T1 than in T2 in 2018 and 2019, mostly due to Diptera Nematocera. Visual sampling revealed that the feeding damage produced by Eriophyidae (Trombidiformes) was significantly lower in T2 in 2018 and 2019: 10–40% of shoots were affected in the late season compared with 50–60% affected for T1. The feeding symptoms caused by Palpita unionalis Hübner (Lepidoptera: Crambidae) and Zelleria oleastrella (Milliere) (Lepidoptera: Yponomeutidae) were significantly less for T2 than for T1. Multivariate principal response curves showed significant differences between irrigation strategies in the 2018 and 2019 data for both sampling methods. In conclusion, irrigation schemes with restricted water use (T2—RDI) help to reduce the abundance of several types of pests in olive crops, especially of those that feed on the plants' new sprouts. [ABSTRACT FROM AUTHOR]

An irrigation experiment was conducted during 5 years in two hedgerow olive orchards (C and L) cv. Arbequina in Central Spain. The control treatments (C1 and L1) were irrigated to maintain the "wetted bulb" near field capacity throughout the season. Three deficit-irrigation treatments were applied from shoot growth (April-May) until pit hardening (beginning of July) with water applications relative to control, C2, C3, C4 (50, 25, 0%) and L2, L3, L4 (40, 17, 0%), respectively. Treatments reverted to full irrigation after pit hardening. During the treatment period a series of phenological events occurs: bud break, shoot growth, flower differentiation, flowering, fruit set, fruit drop and pit hardening. Responses of vegetative growth, flowering, fruiting, fruit characteristics and production were evaluated through their relationships with midday stem water potential (Ψstem). Flowering was shown to be the most sensitive period to deficit irrigation and the major determinant of final production through reductions on fruit number and oil content. With high water during flowering (mean Ψstem before irrigation >−1.0 MPa) trees developed more nodes, leaves, fertile inflorescences and fruits per inflorescence with consequent high production (1278 kg oil ha−1). Oil production was significantly reduced (64% of maximum) when Ψstem was allowed to fall below −1.5 MPa at flowering and was halved at −1.7 MPa, reducing water productivity from 0.26 to 0.21 kg oil m−3. In contrast, Ψstem could be reduced to −1.8 MPa after flowering until pit hardening without effects on fruit drop, fruit size or oil content. Fruit drop increased when Ψstem from flowering until pit hardening was below −2.71 MPa. Fruit oil content at harvest was strongly related with fruit dry weight at pit hardening. Vegetative growth occurred continuously during spring, although mainly during flowering, and could not be reduced by deficit irrigation without reducing production. The results are advantageous to irrigation management in this and similar climatic regions where Spring is a critical period for olive production due to variable temperature, rainfall and crop water demand. They establish the high thresholds of Ψstem required to guide irrigation management during Spring without yield loss, and the substantial resulting loss when this threshold is exceeded. They also reveal that deficit irrigation strategies cannot be used in Spring to control canopy size in hedgerow orchard without serious impact on yield. • Deficit irrigation from bud break until pit hardening affected vegetative growth, number of fruits and production. • During flowering the Ψstem must be greater than −1.5 MPa for higher components of yield production and water productivity. • From flowering to pit hardening the Ψstem should be maintained higher to −1.8 MPa, for high oil accumulation. • In high density orchards vegetative growth cannot be control during flowering without affecting production. [ABSTRACT FROM AUTHOR]

Irrigation sustainability is particularly important in the vicinity of Doñana National Park (Huelva, Spain), where Europe's most important wetland area coexists with a profitable strawberry irrigation activity. In this paper, an innovation and technology transfer project was laid out. The project was promoted by the Institute of Agricultural and Fisheries Research and Training (IFAPA), belonging to the Regional Government of Andalusia. The main objective of the project was to contribute to the sustainability of the complex ecological, productive, and social system of this region. The project was focused on the rational use of water resources. Experimentation, demonstration, technology transfer, and training activities were carried out, involving public administrations, companies, and private farms. The project was carried out in collaboration with strawberry companies covering a total surface area of 1900 hectares. Irrigation application efficiency and irrigation water productivity increased by 66% and there was also a significant increase in water saving (44%), without resulting production losses. The success of the activity was based on the implication of farmers in experimentation assignments. During a five-year time span, irrigation trials took place on several farms. This fact allowed a progressive improvement of irrigation management by farmers based on confidence in the experimental work results. [ABSTRACT FROM AUTHOR]

This work examines the transformations occurred with the shift from private company to water user association and natural park, looking at one collective irrigation system located in Alicante province (Spain): Riegos de Levante, Izquierda del Segura, one of the most extensive irrigation areas in Europe. Between 1918 and 2018, a process of change and transformation of both landscape and institutions occurred, considering: infrastructure expansion and its operation, the transfer of irrigation management responsibilities to water user association, after years of financial operations with water, thanks to state intervention, the coexistence of traditional agriculture with the modernisation of the irrigation systems, the history of an irrigation reservoir which was transformed into a natural site in 1988, or the evolution of the composition of water resources, taking into account the arrival of the Tajo-Segura transfer waters from the year 1979. The general objective is to understand key factors driving these changes, by means of a paradigmatic case study, as well as to identify policymaking and context-relevant dynamics that could enable it. [ABSTRACT FROM AUTHOR]

The irrigation sector has undergone a remarkable transformation in recent decades due to the application of pressurized water distribution technologies, improving the management of limited water resources. As a result of this transformation, irrigation has become, together with agricultural machinery, the primary consumer of energy within the agri-food sector. Furthermore, the energy cost of operating pumping equipment during a farming season represents 30–40% of the crop's total cost. For this reason, one of the most interesting challenges in this scope is that of improving energy efficiency and reducing economic costs so that productive work become more and more competitive. Energy audit makes possible to determine the efficiency of installations, and enables to determine energy saving protocols (requirements), for this reason the aim of this article is to carry out these by using IoT-based systems. The proposed system improves decision-making on agricultural pumping management by classifying wells' efficiency and integrating the data sets that determine their efficiency into a single information model. The system monitors energy efficiency according to different parameters such as: infrastructure, energy consumption, electric rates, manometric height or type of installation, making it possible to enhance each pumping operation's decisions. This solution has been deployed in an irrigation community in southeast Spain whose results have warned about the lack of efficiency in two of its wells: in one of them it is proposed that they be replaced, due to the high cost of pumping water, and in the other, hydraulic mechanisms are implemented to improve the water-energy binomial. [ABSTRACT FROM AUTHOR]

This paper reveals reductions of up to 485 t CO2 eq (CO2 equivalent) of greenhouse gas (GHG) emissions of energy origin associated with the water-energy binomial which can be achieved after modernizing and automating a Water User Association (WUA) of over 1780 users with microplots in a total area of 775 ha in southeastern Spain. This case study aims to show how the latest advances in information and communication technologies (ICTs) for precision agriculture are being applied efficiently with the implementation of a Smart Agri system, capable of making improvements through the use of renewable energies (64.49% of the total CO2e- avoided), automation in irrigation water management, by applying adequate governance, use of ICTs (731,014 m3 per water footprint reduction with 20.41% of total CO2 eq of associated electrical origin), hydraulic improvements (283,995 m3 per water footprint reduction, 13.77% of the total CO2 eq of associated electrical origin) and reduction of evaporation in reservoirs (26,022 m3 of water by water footprint reduction with 1.33% of the total CO2 eq electrical origin avoided) that act as batteries to accumulate the daily solar energy and enable watering at night, when irrigation is most efficient. It is important to consider the valuable contribution of these artificial green lungs, not only in terms of food for the European Union, but also as a CO2 eq sink that supports the planet's GHGs. As shown in this study, this is made possible by the joint governance led by the Water Users Association (WUA) and co-led by different management organizations with the support of ICT. [ABSTRACT FROM AUTHOR]