Deficit irrigation in fruit trees and vines in Spain

[ENG] Water has become the most precious of natural resources in many areas of Spain and, since agriculture is the major consumer of water, improvements in water use efficiency are increasingly sought. Regulated deficit irrigation (RDI) is an irrigation strategy based on applying only a fraction of the plant water requirements during certain periods of plant development. The paper reviews the available information on RDI strategies, in woody tree crops and vines based on studies by Spanish research groups. Both the promising results obtained and the drawbacks are covered. [ESP] El agua se ha convertido en el más preciado de los recursos naturales en muchas zonas de España y, dado que la agricultura es el principal consumidor, es prioritario mejorar la eficiencia de uso del agua en la agricultura de regadío. El riego deficitario controlado (RDC) es una estrategia de riego que se basa en aplicar tan sólo una fracción de los requerimientos hídricos del cultivo durante determinados períodos del ciclo vegetativo. En este trabajo se presenta la información disponible sobre diferentes estrategias de RDC aplicadas en cultivos leñosos y vid, basada en estudios realizados por grupos de investigación españoles. Se discuten las ventajas y desventajas así como los prometedores resultados obtenidos.This research was supported by Spanish Ministry of Science and Innovation MICINN (AGL2006-12914- C02-01; AGL2007-66279-C03-03/AGR; AGL2009- 06981), Séneca Foundation, Murcia (08845/PI/08; 08847/PI/08), and Rideco-Consolider CSD2006-00067 grants to the authors

Validation of a methodology for grouping intakes of pressurized irrigation networks into sectors to minimize energy consumption

A methodology to optimise the amount of energy consumed in pressurized irrigation systems was presented by Jimenez-Bello et al. (2010a). These authors proposed grouping pressurized irrigation network intakes, each of the water turnouts resulting from a shared hydrant, into sectors via a genetic algorithm. In the present research, the methodology was applied and validated in a water users association. Several energy efficiency indicators were calculated and compared during five consecutive seasons (2006-2010). The first two seasons, when the methodology was not employed, were used as reference for the results obtained from 2008 onwards, when the methodology was applied to the management of irrigation network. Results obtained in seasons 2008-2010 showed that the average energy savings were 16% in comparisons to the 2006 season. However, it should be noted that the potential, theoretical savings, could have been as high as 22.3% if the modelled grouping networks would have been accurately followed. There was in fact some discrepancy between the theoretical model outputs and the final groupings due to some intake restrictions. In addition, during the irrigation campaigns, the number of irrigation intakes that operated within each sector was not always equal to the modelled sectoring, a fact that reduced the overall water users association energy efficiency. This occurred particularly during rainy periods, when some users deliberately decided to close their manual irrigation intakes valves. Overall, results showed the potential of the validated methodology for optimising energy use. However, the final overall system efficiency might depend on specific constraints that need to be taken into account when attempting to use model output predictions.This research was supported by funds from Interreg IV SUDOEB project "Telerieg" and from MICIIN project Rideco CSD2006-0067. The authors would like to thank the Company Tecnicas Valencianas del Agua (TECVASA) and the IMPIVA institute for their support in this research study.Jiménez Bello, MÁ.; Martínez Alzamora, F.; Castel, JR.; Intrigliolo Molina, DS. (2011). Validation of a methodology for grouping intakes of pressurized irrigation networks into sectors to minimize energy consumption. Agricultural Water Management. 102(1):46-53. https://doi.org/10.1016/j.agwat.2011.10.005S4653102

Water balance and crop coefficient estimation of a citrus orchard in Uruguay

The actual evapotranspiration (ETc) of mature ¿Valencia¿ orange trees [Citrus sinensis (L.) Osb.], drip-irrigated and non-irrigated, was calculated using the water balance method, over three years. Annual ETc was 24% higher from irrigated trees that from non irrigated trees (767 and 620 mm year-1, respectively). Maximum monthly average ETc was 3.3 mm day-1 or 80 L tree-1 day-1 (trees were spaced at 6 ¥ 4 m). Generally ETc rate was reduced in January, the month of maximum atmospheric demand, compared with December, even under fully irrigated trees. The average annual value of the crop coefficient (Kc) for irrigated trees was 0.69. Monthly Kc values also showed a clear seasonal trend, with minimum values in summer (0.60), intermediate values in autumn and spring (0.77 and 0.80, respectively) and maximum values in winter (0.87). These values provide a useful base for the design and operation of micro-irrigation systems, for mature citrus trees in Uruguay.Se estimó la evapotranspiración real de árboles de naranjo ¿Valencia¿ [Citrus sinensis (L.) Osb.], sin riego y regados por goteo, mediante la metodología del balance hídrico, durante tres años. La ETc fue 24% mayor en los árboles regados que en los de secano (767 y 620 mm anuales, respectivamente). La evapotranspiración media en el mes de máxima demanda fue de 3,3 mm día-1 ó 80 L árbol-1 día-1 (para un marco de plantación de 6 ¥ 4 m, 24 m2). Se repitió sistemáticamente que la tasa de ETc tuvo un descenso en enero, mes de máxima demanda atmosférica, comparado con diciembre, aún en los árboles bien regados. El coeficiente de cultivo (Kc) promedio anual para los árboles regados fue 0,69. Se encontró un claro y sistemático comportamiento estacional, con valores mínimos del Kc en verano (0,60) intermedios en otoño y primavera (0,77 y 0,80, respectivamente) y máximos en el invierno (0,87). Estos valores deberían ser la base para el diseño y la operación de sistemas de riego localizado para explotaciones de cítricos adultos en Uruguay

The response of Valencia orange trees to irrigation in Uruguay

Se realizó un experimento durante cinco años consecutivos (1995-2000) en la zona sur de Uruguay, en naranjos "Valencia" adultos regados por goteo. Los tratamientos aplicados fueron: secano (T1), riego 50%Etc (T2), 100%Etc(T3), 150%ETc(T4), riego-estrés-riego (T5, a igual dosis que el T3, pero se cortó el riego desde el fin de la caída de frutos, a mediados de diciembre, hasta mediados de febrero). El incremento de la sección del tronco y del volumen de copa tuvieron una respuesta lineal y positiva a la dosis de agua aplicada. Ni el número de flores producidas ni el porcentaje de cuajado fueron afectados por los tratamientos. En promedio, el rendimiento con T3 fue un 31% superior que con T1. El tamaño del fruto fue el componente de la producción total más afectado por el riego. El rendimiento de frutos de tamaño exportable fue casi el doble en el tratamiento regado que en el secano (36,7 y 19,2 t ha-1 año-1 respectivamente). El T3 dio los mejores resultados productivos. El T2 significó, en promedio, un ahorro de 738 m3 ha-1 año-1 de agua, produjo árboles de menor tamaño, y una reducción moderada (14%) de la producción de tamaño exportable. El T4 utilizó más agua que el T3, produjo árboles de mayor tamaño, pero no mejoró la producción. El T5 significó un menor ahorro de agua que el T2 (547 m3 ha-1 año-1), pero una mayor reducción (22%) de la producción exportable

PROGRAMACIÓN DE RIEGO EN CÍTRICOS EN BASE A SENSORES DE MEDIDA DEL ESTADO HÍDRICO DEL SUELO Y DE LA PLANTA IRRIGATION SCHEDULING IN CITRUS BASED ON SOIL AND PLANT WATER STATUS MEASURING SENSORS

Durante el 2004, se realizó un experimento de riego deficitario controlado (RDC) en una parcela de "Clementina de Nules/Citrange carrizo", en valencia España, en el que se estudiaron tres programaciones de riego diferentes basadas en: i) la planta (dendrómetros) y ii) riego deficitario fijo. Todas ellas, se compararon con un control bien regado durante todo el año, al 100% de la evapotranspiración de un lisímetro de pesada (ETlis), situado en la misma parcela. Los tratamientos diferenciales de riego, se iniciaron tras la caída fisiológica de frutos y su duración coincidió con el periodo de crecimiento más activo del fruto, desde mediados de julio hasta octubre. Durante el resto del año, todos los tratamientos se regaron al 100% de la ETlis. A los tratamientos regados en base a la información de la planta (MCD1,25 y MCD 1,35) se les aplicó semanalmente un volumen de agua variable para mantener la máxima contracción diaria del tronco (MCD), en torno al 125 y 135%, respectivamente, de la del control. El tratamiento de riego deficitario sostenido (RDfijo) consistió en la aplicación de un 52% ETlis durante el periodo de restricción. Los resultados muestran que en los tratamientos MCD fue posible programar el riego para mantener el MCD relativo en los valores prefijados de 125 y 135%, respectivamente. La producción y el número de frutos por árbol fue significativamente menor (pAn experiment on regulated deficit irrigation (RDI) strategies was performed during 2004 in an orchard of ‘Clementina de Nules'/'Citrange carrizo' In Valencia Spain. Three different irrigation scheduling protocols were compared. Two approaches were based on the information derived from the plant and a third one managed on a sustained, fixed deficit application. Deficit irrigated treatments were compared to a well-watered control treatment, irrigated at 100% of a weighting lysimeter evapotranspiration (ETlis) located in the same orchard. Water restrictions were applied during the fruit growth period after June fruit drop, from July to October, and during the rest of the year all treatments were irrigated at 100% ETlis. Irrigation management based on plant measurements consisted of a variable application rate in order to maintain the maximum daily stem contraction close to 125% and 135% of MDS value of control treatment (MDS ratio management). Finally, the third deficit irrigation treatment was irrigated at 52% of ETlis during the whole restriction period. The results show that was possible to schedule irrigation based on MDS information in order to maintain the MDS ratio respect to the control around the preset values of 125% and 135% respectively. Yield and number of fruit per tree was significantly lower (p <0,05) respect to control the RDfixed and MCD 1,35, but not in the MCD 1,25 treatments. Fruit size distribution and fruit quality in all treatment did not differ significantly (p <0,05) respect to control, despite the water saving achieved, which ranged from 12 to 19%, on an seasonal basis

Irrigation scheduling in citrus based on soil and plant water status measuring sensors

Durante el 2004, se realizó un experimento de riego deficitario controlado (RDC) en una parcela de “Clementina de Nules/Citrange carrizo”, en valencia España, en el que se estudiaron tres programaciones de riego diferentes basadas en: i) la planta (dendrómetros) y ii) riego deficitario fijo. Todas ellas, se compararon con un control bien regado durante todo el año, al 100% de la evapotranspiración de un lisímetro de pesada (ETlis), situado en la misma parcela. Los tratamientos diferenciales de riego, se iniciaron tras la caída fisiológica de frutos y su duración coincidió con el periodo de crecimiento más activo del fruto, desde mediados de julio hasta octubre. Durante el resto del año, todos los tratamientos se regaron al 100% de la ETlis. A los tratamientos regados en base a la información de la planta (MCD1,25 y MCD 1,35) se les aplicó semanalmente un volumen de agua variable para mantener la máxima contracción diaria del tronco (MCD), en torno al 125 y 135%, respectivamente, de la del control. El tratamiento de riego deficitario sostenido (RDfijo) consistió en la aplicación de un 52% ETlis durante el periodo de restricción. Los resultados muestran que en los tratamientos MCD fue posible programar el riego para mantener el MCD relativo en los valores prefijados de 125 y 135%, respectivamente. La producción y el número de frutos por árbol fue significativamente menor (p <0,05) en los tratamientos MCD1,35 y RDfijo, que en el tratamiento control, pero no lo fue en el tratamiento MCD1,25 . La distribución por calibres y por calidad de fruta no difirió significativamente (p <0,05) del control en ninguno de los tratamientos, a pesar del ahorro de agua obtenido, que osciló entre el 12 y el 19%, en base anual.An experiment on regulated deficit irrigation (RDI) strategies was performed during 2004 in an orchard of ‘Clementina de Nules’/’Citrange carrizo’ In Valencia Spain. Three different irrigation scheduling protocols were compared. Two approaches were based on the information derived from the plant and a third one managed on a sustained, fixed deficit application. Deficit irrigated treatments were compared to a well-watered control treatment, irrigated at 100% of a weighting lysimeter evapotranspiration (ETlis) located in the same orchard. Water restrictions were applied during the fruit growth period after June fruit drop, from July to October, and during the rest of the year all treatments were irrigated at 100% ETlis. Irrigation management based on plant measurements consisted of a variable application rate in order to maintain the maximum daily stem contraction close to 125% and 135% of MDS value of control treatment (MDS ratio management). finally, the third deficit irrigation treatment was irrigated at 52% of ETlis during the whole restriction period. The results show that was possible to schedule irrigation based on MDS information in order to maintain the MDS ratio respect to the control around the preset values of 125% and 135% respectively. Yield and number of fruit per tree was significantly lower (p <0,05) respect to control the RDfixed and MCD1,35, but not in the MCD1,25 treatments. fruit size distribution and fruit quality in all treatment did not differ significantly (p <0,05) respect to control, despite the water saving achieved, which ranged from 12 to 19%, on an seasonal basis.Incluye referencias bibliográfica

Review: Deficit irrigation in fruit trees and vines in Spain

Water has become the most precious of natural resources in many areas of Spain and, since agriculture is the major consumer of water, improvements in water use efficiency are increasingly sought. Regulated deficit irrigation (RDI) is an irrigation strategy based on applying only a fraction of the plant water requirements during certain periods of plant development. The paper reviews the available information on RDI strategies, in woody tree crops and vines based on studies by Spanish research groups. Both the promising results obtained and the drawbacks are covered

Soil capacitance sensors and stem dendrometers: useful tools for irrigation scheduling of commercial orchards?

Irrigation scheduling is often performed based on a soil water balance, where orchard evapotranspiration is estimated using the reference evapotranspiration (ETo) times the crop coefficient (Kc). This procedure, despite being widely spread, has some uncertainties. Because of this, plant and soil water status monitoring could be alternatively or complementarily used to schedule irrigation. The usefulness of capacitance probes was evaluated during several seasons in large irrigation districts where irrigation practices were changed over years from the ETo * Kc model to the analysis of soil water status trend. This area corresponds to drip irrigated orchards planted with citrus, peach, nectarine and persimmon. Around 25% less irrigation was applied with no substantial yield penalty when the information provided by capacitance probes was correctly applied for irrigation management. On the other hand, the usefulness of stem dendrometers for continuously monitoring plant water status was evaluated in a young plum experimental orchard. Over two years, irrigation was scheduled using exclusively trunk shrinkage via the signal intensity approach by means of a baseline equation previously obtained in the orchard. Results showed that it was not always possible to schedule irrigation based on the trunk shrinkage signal intensity due to the temporal changes in the reference values that occurred as trees aged. Overall, results obtained are discussed in terms of the possible extrapolation at field level of both capacitance probes and stem dendrometers. Advantages and drawbacks of each technique are analyzed and discussed

Influence of water regime on grape aromatic composition of Muscat of Alexandria in a semiarid climate

Irrigation effects in relation to the environmental conditions on grape aromas are still unknown. This study aims to clarify the effects of water regime on the aromatic composition of “Muscat of Alexandria” grapes under the semiarid climate conditions of eastern Spain and over three seasons. The relationships between total volatile composition in free and glycosidically-bound fractions, vine performance, and grape composition were also assessed. The watering treatments studied were: sustained deficit irrigation (SDI) at 50% of the estimated crop evapotranspiration (ET); early deficit (EDI), where pre-veraison water deficit was imposed; late deficit (LDI), in which a water shortage was applied during post-veraison; and control (C), irrigated at 100% of ET during the entire season. The effects of water regimes on volatile and glycosidically-bound composition were different between seasons due to the predominant effect of the environmental conditions on aromatic composition. The seasons with the greater yield were associated to a lower grape aromatic composition, however, this effect at the crop level was less pronounced in the most irrigated treatment. In drier seasons, irrigation delayed ripening and increased the terpene concentration of “Muscat of Alexandria” grapes, showing a high treatment and season interaction. Specific water regimes have the potential to buffer the effects of environmental conditions on the aromatic composition of “Muscat of Alexandria” grapes in a semi-arid climate, as the result of the complex relationships between climatic factors, vine performance and grape maturity.This research was supported by FEDER and INIA funds through Project RTA2011-00100-C01, and is found within the framework of activities carried out under AEI-FEDER funds AGL2017-83738-C3-3-R. We would like to thank Dr. Manuel Marcos from the Scientific and Technological Research Assistance Centre (CACTI, Vigo University, Spain) for the GC/MS service