Impact of climate change on irrigation management for olive orchards at southern Spain

The irrigation management for olive orchards under future weather conditions requires the development of advanced tools for considering specific physiological and phenological components affected by the foreseen changes in climate and atmospheric [CO2]

Quantifying the effect of Tmax extreme events on local adaptation to climate change of maize crop in Andalusia for the 21st century

Extreme events of Tmax can threaten maize production on Andalusia (Ruiz-Ramos et al., 2011). The objective of this work is to attempt a quantification of the effects of Tmax extreme events on the previously identified (Gabaldón et al., 2013) local adaptation strategies to climate change of irrigated maize crop in Andalusia for the first half of the 21st century

Response of maize and olive to climate change under the semi-arid conditions of southern Spain

Global climate projections indicate an increase in atmospheric CO2 concentration causing for Mediterranean regions an increase in both mean and maximum temperatures, an average decrease in precipitation and an increase in the temporal and spatial variability of extreme events related with rainfall, such as droughts. All these changes in many areas within Andalusia region (southern Spain) would have a direct impact on the agriculture, a critical sector with great social and economic importance. This Thesis is a further step in the knowledge of the impact assessment that climate projections may have on agriculture in the region. To achieve this purpose, two ensembles of regional climate models (ENS-EOBS and ENS-Spain02) with a bias correction in temperature and precipitation were used in order to reduce the uncertainty linked to the use of climate models. Crop development, growth and yield under these climate conditions were simulated using crop models previously sitespecific calibrated and validated. The assessment of these impacts aims to be useful for decision-making, allowing exploring the potential of adaptation measures to maintain or even increase the yield under future climate conditions. In this Thesis the impacts of climate change on two crops of great importance in Mediterranean regions were evaluated. On the one hand, the maize crop, a reference irrigated crop under semi-arid conditions, which was analyzed in the first two chapters of the Thesis. On the other hand, the olive, crop extensively cultivated in Andalusia, the main olive oil producer region in the World, that was analyzed in Chapter 3. Chapter 1 describes the impacts and adaptation to climate change for maize cultivated in five locations of Andalusia. For this purpose experimental data obtained from irrigated maize (FAO-700 cycle) under not limiting conditions of water and nutrients were considered. With these data CERES-Maize model under the DSSAT platform was calibrated and validated. For the consideration of climate data several sources were used; for the observed climate, data from the Agro-climatic Information Network of Andalusia (RIA) was used and for the simulated climate, data from an ensemble of twelve regional models (ENS-EOBS) with a bias correction in temperature and precipitation over the original European project ENSEMBLES was used. The results for the end of the 21st century project a reduction in the maize crop cycle length causing a decrease in the duration of the grain filling period and then, a decrease in yield maize and irrigation requirements. In addition, the stomatal closure caused by the increase in CO2 concentration, could lead to an increase in the water use efficiency. To reduce the negative impacts on maize crop, in this Thesis some adaptation measures were evaluated. Thus, some proposed adaptations were to advance the sowing date 30 days earlier than current and to change the maize cultivar seeking to increase the grain filling period and its efficiency. These adaptations offset the yield losses and even in some cases, the projected yield was increased. The impacts and the adaptation strategies effect were also evaluated from the point of view of the incidence of extreme temperature events at flowering, showing an increase in the number of extreme events as well as in the production damage at the end of the 21st century. The proposed adaptation strategies previously described resulted in an overall reduction of crop damage by extreme maximum temperatures at all locations with the exception of specific locations such as Granada, where losses were limited to 8 %. With this precedent, the Chapter 2 deals with the modelling of heat stress events on maize yield. A heat stress response function was developed and evaluated into the modeling framework SIMPLACE, within the Lintul5 crop model and the canopy temperature model (CanopyT). For this task, experimental data from Pergamino (Argentina) considering a maize temperate hybrid, and from Lleida (Spain), with a maize cultivar FAO-700 cycle, were used. In both experiments the maize plants were subjected to high temperature conditions around flowering by placing polyethylene tents. Argentine data were used to obtain a yield reduction factor in relation with thermal time under a critical temperature of 34 °C during the flowering period. On the other hand, the Spanish data were divided into two sets, one of them under control conditions to calibrate the model, and the other set to validate it using the reduction factor obtained from the Argentina data. The model evaluated consider canopy temperature (Tcan) or air temperature (Tair) for the simulation of impact of heat events on maize yield, obtaining better model performance using Tcan when the critical temperature was set to 34 °C. However, when critical temperature for Tair was increased to 39 °C, the results were similar for both temperatures (canopy and air) indicating that for irrigated and high radiation conditions the air temperature could be used as input in the model without the need to simulate the canopy temperature. The Chapter 3 evaluates the impacts of climate change on olive flowering for current and future climate conditions at southern Spain. For this purpose an experiment located at Cordoba from 1st October 2013 to the end of May 2014 was set to evaluate ten olive genotypes under two different climate conditions, one outdoors (OU) and the other inside of a greenhouse (GH). The aim of the experiments carried out in GH was to identify the impacts of the increase in temperatures on olive phenology, reproducing the mean increment of maximum and minimum temperatures (DTmax, DTmin) projected at the end of the 21st century. To quantify these increases, data from an ensemble of twelve regional climate models (ENS-Spain02), with a bias correction in temperature and precipitation from the original climate models of the ENSEMBLES European project were used. Once the foreseen climate conditions were reproduced in GH, olive flowering dates were evaluated under both climate conditions using previous flowering models, obtaining good results under OU conditions, but not for GH. Based on these results, a new model was proposed and evaluated taken into account on one hand the chilling hour accumulation and on the other hand obtaining the flowering dates achieved after heating accumulation. Once the new model was developed, flowering dates were evaluated for the whole region of Andalusia, obtaining a mean advance in the flowering date of 17 days for all the genotypes for the climate conditions foreseen at the end of the 21st century. A spatial analysis of the results was carried out, identifying the highest advance in flowering date in the mountainous area of Jaen and Granada provinces and the lowest in the Atlantic Ocean Coast area. Finally, a spatial analysis evaluating the vulnerable and suitable areas for olive cultivation in Andalusia at the end of the 21st century was held. Thus, several areas were vulnerable due to high temperatures in flowering (North and Northeast regions) or to lack of chilling hour accumulation in winter (Atlantic Ocean and the Southeast coast). Equally, potential new areas for olive cultivation were detected as the southern area of Andalusia. RESUMEN Las proyecciones climáticas globales indican un aumento en la concentración de CO2 atmosférico que, para las regiones mediterráneas, implican un aumento tanto en las temperaturas medias como en las máximas, una disminución promedio de las precipitaciones y un aumento de la variabilidad temporal y espacial de los fenómenos extremos relacionados tanto con la lluvia como con las sequías. Todos estos cambios tendrían un impacto directo en la agricultura de muchas áreas de la región de Andalucía (sur de España), sector crítico de gran importancia social y económica. Esta tesis es un paso más en el conocimiento de la evaluación de impactos que las proyecciones climáticas pueden tener sobre la agricultura en la región. Para lograr este propósito, se han utilizado dos conjuntos de modelos climáticos regionales (ENSEOBS y ENS-Spain02) con una corrección del sesgo de la temperatura y la precipitación con el fin de reducir la incertidumbre relacionada con el uso de modelos climáticos. El desarrollo del cultivo, crecimiento y rendimiento en estas condiciones climáticas se han simulado utilizando modelos de cultivos previamente calibrados y validados localmente. La evaluación de estos impactos pretende ser útil para la toma de decisiones, lo que permite explorar el potencial de las medidas de adaptación para mantener o incluso aumentar el rendimiento bajo condiciones climáticas futuras. En esta Tesis han evaluado los efectos del cambio climático en dos cultivos de gran importancia en las regiones mediterráneas. Por un lado, el maíz, un cultivo en regadío de referencia en condiciones semiáridas, analizado en los dos primeros capítulos de la tesis. Por otro lado, el olivo, ampliamente cultivado en Andalucía, siendo la principal región productora de aceite de oliva a nivel mundial; este cultivo se analiza en el Capítulo 3. El Capítulo 1 se describe los impactos y adaptaciones al cambio climático para el maíz cultivado en cinco localizaciones de Andalucía. Para este fin se han utilizado datos experimentales obtenidos a partir de maíz en regadío (ciclo FAO-700) bajo condiciones no limitantes de agua y nutrientes. Con estos datos el modelo CERES-Maize bajo la plataforma DSSAT se ha calibrado y validado. Los datos climáticos considerados en este estudio proceden de varias fuentes; para el clima observado, se han utilizado los datos de la Red de Información Agro-climáticas de Andalucía (RIA), y para el clima simulado, los datos de un conjunto de doce modelos regionales (ENS-EOBS) con una corrección del sesgo en la temperatura y la precipitación sobre los modelos originales del proyecto Europeo ENSEMBLES. Los resultados obtenidos para el final del siglo XXI proyectan una reducción en la longitud del ciclo del maíz causando una disminución en la duración del periodo de llenado de grano y, por tanto, una disminución del rendimiento del maíz y de las necesidades de riego. Además, el cierre estomático causado por el aumento de la concentración de CO2, podría conducir a un aumento en la eficiencia del uso del agua. Para reducir los impactos negativos sobre el cultivo de maíz, en esta Tesis se evalúan algunas medidas de adaptación. De este modo, algunas adaptaciones propuestas son el adelanto de la fecha de siembra 30 días antes de la fecha actual y el cambio de la variedad de maíz buscando aumentar la eficiencia y período de llenado del grano.. Estas adaptaciones compensan las pérdidas de rendimiento e incluso en algunos casos, las proyecciones indican un aumento del rendimiento. Los impactos y el efecto estrategias de adaptación también se han evaluado desde el punto de vista de la incidencia de eventos extremos de temperatura en la floración, mostrando un aumento en el número de eventos extremos, así como en el daño en la producción a finales del siglo XXI. Las estrategias de adaptación propuestas descritas anteriormente dieron lugar a una reducción en los daños por temperaturas máximas extremas en todos los lugares, con la excepción de zonas específicas, como Granada, donde las pérdidas se limitan al 8 %. Una vez identificado el problema en el Capítulo 1, una vía de solución se plantea en el Capítulo 2, que trata la modelización de eventos de estrés térmico en el rendimiento del maíz. Una función de respuesta al estrés térmico fue desarrollado y evaluado en el marco de modelado SIMPLACE, dentro del modelo de cultivo Lintul5 y de un modelo de temperatura de la cubierta (CanopyT). Para este cometido se han utilizado datos experimentales de Pergamino (Argentina) considerando un híbrido templado maíz, y de Lleida (España), con un ciclo de cultivo de maíz FAO-700. En ambos experimentos las plantas de maíz fueron sometidas a condiciones de alta temperatura alrededor de la floración mediante la colocación de tiendas de polietileno. Los datos de Argentina se han utilizado para obtener un factor de reducción de rendimiento en relación con el tiempo térmico durante el periodo de floración considerando una temperatura crítica de 34 °C. Por otra parte, los datos de España se dividieron en dos grupos, uno de ellos en condiciones de control para calibrar el modelo, y el otro conjunto para validarlo usando el factor de reducción obtenido a partir de los datos de Argentina. El modelo evaluado considera la temperatura de cubierta (Tcan) o la temperatura del aire (Tair) para la simulación del impacto de los eventos de calor sobre el rendimiento del maíz, obteniendo un mejor resultado utilizando Tcan cuando la temperatura crítica se fijó en 34 °C. Sin embargo, cuando la temperatura crítica para Tair se aumentó a 39 °C, los resultados fueron similares para ambas temperaturas (cubierta y aire) que indican que para las condiciones de riego y alta radiación la temperatura del aire se podría utilizar como dato de entrada en el modelo sin necesidad de simular la temperatura de la cubierta. El Capítulo 3 evalúa los impactos del cambio climático en la floración del olivo para las condiciones climáticas actuales y futuras en el sur de España. Para este propósito se ha llevado a cabo un experimento en la localidad de Córdoba desde el 1 de Octubre 2013 hasta finales de Mayo 2014 en el que se han evaluado diez genotipos de olivo en dos condiciones climáticas diferentes, uno en el exterior (OU) y el otro en el interior de un invernadero (GH). El objetivo de los experimentos llevados a cabo en GH fue identificar los impactos del aumento de las temperaturas en la fenología del olivo, reproduciendo el incremento medio de las temperaturas máximas y mínimas (DTmax, DTmin) proyectados al final del siglo XXI. Para cuantificar estos aumentos, se han utilizado los datos de un conjunto de doce modelos climáticos regionales (ENS-Spain02), con una corrección en el sesgo de la temperatura y la precipitación de los modelos climáticos sobre los originales del proyecto Europeo ENSEMBLES. Una vez que las condiciones climáticas previstas fueron reproducidas en GH, las fechas de floración del olivo han sido evaluadas bajo las dos condiciones climáticas usando modelos de floración anteriores, obteniendo buenos resultados en condiciones OU, pero no para GH. Basándose en estos resultados, se ha propuesto y evaluado un nuevo modelo teniendo cuenta por un lado la acumulación frío y por otra parte el cálculo de las fechas de floración después de un periodo de acumulación por calor. Una vez desarrollado el nuevo modelo, se han evaluado las fechas de floración para toda la región de Andalucía, obteniendo un adelanto medio en la fecha de floración de 17 días para todos los genotipos bajo las condiciones climatológicas previstas al final del siglo XXI. Finalmente se realizó un análisis espacial de los resultados, identificando el mayor adelanto en la fecha de floración en las zonas montañosas de las provincias de Jaén y Granada y la menor en la costa del océano Atlántico. Igualmente, se ha realizado un análisis espacial evaluando las áreas vulnerables y adecuadas para el cultivo del olivo en Andalucía a finales del siglo XXI. De este modo, varias zonas muestran vulnerables a las altas temperaturas en floración (regiones Norte y Nordeste) o por falta de acumulación de frío en invierno (costa del Océano Atlántico y la costa sureste). Igualmente, se han identificado nuevas áreas potenciales para el cultivo del olivo como la zona sur de Andalucía

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Technical document showing the results of studies on the possible impacts of climate change on the Andalusian irrigated maize cropping system and adaptation measures evaluated to limit themResultados de estudios sobre los posibles impactos del cambio clim&aacute;tico sobre el cultivo del ma&iacute;z regad&iacute;o en Andaluc&iacute;a y medidas de adaptaci&oacute;n evaluadas para limitarlos.</p

Strategies for adapting maize to climate change and extreme temperatures in Andalusia, Spain

Climate projections indicate that rising temperatures will affect summer crops in the southern Iberian Peninsula. The aim of this study was to obtain projections of the impacts of rising temperatures, and of higher frequency of extreme events on irrigated maize, and to evaluate some adaptation strategies. The study was conducted at several locations in Andalusia using the CERESMaize crop model, previously calibrated/validated with local experimental datasets. The simulated climate consisted of projections from regional climate models from the ENSEMBLES project; these were corrected for daily temperature and precipitation with regard to the E-OBS observational dataset. These bias-corrected projections were used with the CERES-Maize model to generate future impacts. Crop model results showed a decrease in maize yield by the end of the 21st century from 6 to 20%, a decrease of up to 25% in irrigation water requirements, and an increase in irrigation water productivity of up to 22%, due to earlier maturity dates and stomatal closure caused by CO2 increase. When adaptation strategies combining earlier sowing dates and cultivar changes were considered, impacts were compensated, and maize yield increased up to 14%, compared with the baseline period (1981−2010), with similar reductions in crop irrigation water requirements. Effects of extreme maximum temperatures rose to 40% at the end of the 21st century, compared with the baseline. Adaptation resulted in an overall reduction in extreme Tmax damages in all locations, with the exception of Granada, where losses were limited to 8%.JRC.H.7-Climate Risk Managemen

Impact of climate change on irrigation management for olive orchards at southern Spain

The irrigation management for olive orchards under future weather conditions requires the development of advanced tools for considering specific physiological and phenological components affected by the foreseen changes in climate and atmospheric [CO2]

Phenological diversity in a World Olive Germplasm Bank: Potential use for breeding programs and climate change studies

Aim of study: Crop phenology is a critical component in the identification of impacts of climate change. Then, the assessment of germplasm collections provides relevant information for cultivar selection and breeding related to phenology, being the base for identifying adaptation strategies to climate change.Area of study: The World Olive Germplasm Bank located at IFAPA Centre “Alameda del Obispo” (WOGB-IFAPA) in Cordoba (Southern Spain) was considered for the study.Material and methods: Data gathered for nine years on flowering and ripening time of olive cultivars from WOGB-IFAPA were evaluated. Thus, full flowering date (FFD) for 148 cultivars and ripening date (RD) for 86 cultivars, coming from 14 olive growing countries, were considered for characterization of olive phenology and for calibration/validation of phenological models.Main results: The characterization of WOGB-IFAPA has allowed the identification of cultivars with extreme early (‘Borriolenca’) and late (‘Ulliri i Kuq’) flowering as well as the ones with extreme early (‘Mavreya’) and late (‘Gerboui’) ripening dates. However, the very limited inter-cultivar variability, especially for FFD, resulted in a non-optimal simulation models performance. Thus, for FFD and RD the root mean square error was around 6 and 24 days, respectively. The limited inter-cultivar variability was associated to the low average temperatures registered during winter at WOGB-IFAPA generating an early accumulation of the chilling requirements, thus homogenizing FFD of all the analyzed cultivars.Research highlights: The identification of cultivars with early FFD and late RD provides useful information for breeding programs and climate change studies for identifying adaptation strategies

Methodology to assess the changing risk of yield failure due to heat and drought stress under climate change

While the understanding of average impacts of climate change on crop yields is improving, few assessments have quantified expected impacts on yield distributions and the risk of yield failures. Here we present the relative distribution as a method to assess how the risk of yield failure due to heat and drought stress (measured in terms of return period between yields falling 15 below previous 5-year Olympic average yield) responds to changes of the underlying yield distributions under climate change. Relative distributions are used to capture differences in the entire yield distribution between baseline and climate change scenarios, and to further decompose them into changes in the location and shape of the distribution. The methodology is applied here for the case of rainfed wheat and grain maize across Europe using an ensemble of crop models under three climate change scenarios with simulations conducted at 25 km resolution. Under climate change, maize generally displayed shorter return periods of yield failures (with changes under RCP 4.5 between -0.3 and 0 years compared to the baseline scenario) associated with a shift of the yield distribution towards lower values and changes in shape of the distribution that further reduced the frequency of high yields. This response was prominent in the areas characterized in the baseline scenario by high yields and relatively long return periods of failure. Conversely, for wheat, yield failures were projected to become less frequent under future scenarios (with changes in the return period of -0.1 to +0.4 years under RCP 4.5) and were associated with a shift of the distribution towards higher values and a change in shape increasing the frequency of extreme yields at both ends. Our study offers an approach to quantify the changes in yield distributions that drive crop yield failures. Actual risk assessments additionally require models that capture the variety of drivers determining crop yield variability and scenario climate input data that samples the range of probable climate variation

Pan-European multi-crop model ensemble simulations of wheat and grain maize under climate change scenarios

The simulated data set described in this paper was created by an ensemble of nine different crop models: HERMES (HE), Simplace (L5), SiriusQuality (SQ), MONICA (MO), Sirius2014 (S2), FASSET (FA), 4M (4M), SSM (SS), DSSAT-CSM IXIM (IX). Simulations were performed for grain maize (six models) and winter wheat (eight models) under diverse conditions over agriculturally relevant areas in the EU-27 at a 25 x 25 km spatial resolution. Simulations were drawn from combinations of three representative concentration pathways and climate outputs from five general circulation models for time periods 2040-2069 and 2070-2099. Historical climate data was the basis for simulation years 1980-2010 and considered as a baseline. Simulation results from 1980-2010 and 2040-2069 were used to analyze crop responses to changing climatic variables and their diverging sensitivities to these variables. This data paper describes the creation, motivation and format of the simulation results to enable others to use the data set