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Les diferències en la vegetació seminatural dels marges dels camps afectaran els serveis de control biològic derivats de la presència d'aquests hàbitats seminaturals adjacents als camps. Dels trets funcionals de les plantes que són més rellevants per als insectes, les formes de vida vegetal reflecteixen diferents aspectes de l'estructura i el funcionament de les plantes que poden ajudar a predir el valor de la vegetació marginal per als artròpodes en els sistemes agrícoles. L'objectiu d'aquest estudi va ser determinar l'efecte de l'estructura de la vegetació dels marges del camp sobre els pugons dels cereals i sobre alguns dels seus enemics naturals (parasitoides, sirfes i marietes) pel que fa a les formes de vida vegetal. Vam caracteritzar la vegetació del marge utilitzant la cobertura relativa de cada forma de vida i vam fer mostres d'insectes en cultius al llarg de transectes paral·lels als marges del camp. Els nostres resultats mostren que a les zones estudiades, l'abundància d'enemics naturals era més gran prop dels marges dominats per plantes anuals que en els marges dominats per plantes perennes. D'altra banda, les abundàncies de pugons i les taxes de parasitisme eren més altes a prop dels marges dominats per plantes llenyoses perennes que als marges propers dominats per plantes herbàcies perennes. Mitjançant la promoció de formes de vida específiques als marges existents, els agricultors poden millorar el control biològic de conservació i alleujar la pressió dels pugons sobre els seus cultius. Differences in the semi-natural vegetation of field margins will affect the biological control services derived from the presence of these semi-natural habitats adjacent to fields. Of the plant functional traits that are most relevant for insects, plant life forms reflect different aspects of plant structure and functioning that can help predict the value of marginal vegetation for arthropods in agricultural systems. The aim of this study was to determine the effect of the vegetation structure of field margins on cereal aphids and on some of their natural enemies (parasitoids, hoverflies and ladybugs) in terms of plant life forms. We characterized margin vegetation using the relative cover of each life form and sampled insects in crops along transects parallel to field margins. Our results show that in the studied areas, the abundance of natural enemies was greater near margins dominated by annual plants than in margins dominated by perennial plants. On the other hand, the abundances of aphids and parasitism rates were higher near margins dominated by perennial woody plants than near margins dominated by perennial herbaceous plants. By promoting specific life forms in existing margins, farmers can enhance the conservation biological control and relieve aphid pressure on their crops Las diferencias en la vegetación seminatural de los márgenes de los campos afectarán los servicios de control biológico derivados de la presencia de estos hábitats seminaturales adyacentes a los campos. De los rasgos funcionales de las plantas que son más relevantes para los insectos, las formas de vida de las plantas reflejan diferentes aspectos de la estructura y el funcionamiento de las plantas que pueden ayudar a predecir el valor de la vegetación marginal para los artrópodos en los sistemas agrícolas. El objetivo de este estudio fue determinar el efecto de la estructura de la vegetación de los márgenes de los campos sobre los pulgones de los cereales y sobre algunos de sus enemigos naturales (parasitoides, sírfidos y mariquitas) en términos de formas de vida vegetal. Caracterizamos la vegetación del margen usando la cobertura relativa de cada forma de vida y muestreamos insectos en cultivos a lo largo de transectos paralelos a los márgenes del campo. Nuestros resultados muestran que en las áreas estudiadas, la abundancia de enemigos naturales fue mayor cerca de los márgenes dominados por plantas anuales que en los márgenes dominados por plantas perennes. Por otro lado, la abundancia de pulgones y las tasas de parasitismo fueron mayores cerca de los márgenes dominados por plantas leñosas perennes que cerca de los márgenes dominados por plantas herbáceas perennes. Al promover formas de vida específicas en los márgenes existentes, los agricultores pueden mejorar el control biológico de la conservación y aliviar la presión de los áfidos en sus cultivos.

Although organic farming was originally promoted as an alternative farming system to address agronomic, environmental and ecological issues, its conventionalisation has led to an intensification and specialisation of production. In the light of this, several studies have questioned the environmental benefits of organic farming as well as its agronomic viability. Thus, there is a need to improve organic vegetable systems to reduce their environmental impact without affecting their productivity. To tackle this challenge, European farmers and researchers have recently started to focus on agroecological service crops (ASCs). However, few studies have simultaneously evaluated the agronomic, environmental and ecological aspects of ASC management under different European pedo-climatic conditions. We evaluated effects of the ASC management strategies—no-till roller crimping (NT-RC) and green manuring (T-GM) on cropping system performance using agronomic, environmental and ecological indicators—to exemplify the need for multidimensional analysis to understand management implications for addressing environmental and agronomic challenges. We combined the results from 11 organic vegetable field trials conducted in seven European countries over a period of 2 years to test for general trends. Our results provide solid evidence that NT-RC management across different pedo-climatic conditions in Europe enhances the activity density of ground and rove beetles and improves both the potential energy recycling within the system and weed control. However, in NT-RC plots, lower cash crop yield and quality, energetic efficiency of production and activity density of spiders were observed compared to T-GM. Synthesis and applications. Multidimensional analyses using agronomic, environmental and ecological indicators are required to understand the implications of agricultural management in agroecosystem functioning. Introducing agroecological service crops combined with the use of no-till roller crimping is a promising strategy for improving agronomic performance (e.g. fewer weeds) and reducing environmental (e.g. increasing the potentially recyclable energy) and ecological (e.g. enhancing the activity density of beneficial taxa such as ground and rove beetles) impacts. However, our study also indicates a need for agronomic and environmental improvements while promoting a wider acceptance of this strategy. Although organic farming was originally promoted as an alternative farming system to address agronomic, environmental and ecological issues, its conventionalisation has led to an intensification and specialisation of production. In the light of this, several studies have questioned the environmental benefits of organic farming as well as its agronomic viability. Thus, there is a need to improve organic vegetable systems to reduce their environmental impact without affecting their productivity. To tackle this challenge, European farmers and researchers have recently started to focus on agroecological service crops (ASCs). However, few studies have simultaneously evaluated the agronomic, environmental and ecological aspects of ASC management under different European pedo-climatic conditions. We evaluated effects of the ASC management strategies—no-till roller crimping (NT-RC) and green manuring (T-GM) on cropping system performance using agronomic, environmental and ecological indicators—to exemplify the need for multidimensional analysis to understand management implications for addressing environmental and agronomic challenges. We combined the results from 11 organic vegetable field trials conducted in seven European countries over a period of 2 years to test for general trends. Our results provide solid evidence that NT-RC management across different pedo-climatic conditions in Europe enhances the activity density of ground and rove beetles and improves both the potential energy recycling within the system and weed control. However, in NT-RC plots, lower cash crop yield and quality, energetic efficiency of production and activity density of spiders were observed compared to T-GM. Synthesis and applications. Multidimensional analyses using agronomic, environmental and ecological indicators are required to understand the implications of agricultural management in agroecosystem functioning. Introducing agroecological service crops combined with the use of no-till roller crimping is a promising strategy for improving agronomic performance (e.g. fewer weeds) and reducing environmental (e.g. increasing the potentially recyclable energy) and ecological (e.g. enhancing the activity density of beneficial taxa such as ground and rove beetles) impacts. However, our study also indicates a need for agronomic and environmental improvements while promoting a wider acceptance of this strategy. Although organic farming was originally promoted as an alternative farming system to address agronomic, environmental and ecological issues, its conventionalisation has led to an intensification and specialisation of production. In the light of this, several studies have questioned the environmental benefits of organic farming as well as its agronomic viability. Thus, there is a need to improve organic vegetable systems to reduce their environmental impact without affecting their productivity. To tackle this challenge, European farmers and researchers have recently started to focus on agroecological service crops (ASCs). However, few studies have simultaneously evaluated the agronomic, environmental and ecological aspects of ASC management under different European pedo-climatic conditions. We evaluated effects of the ASC management strategies—no-till roller crimping (NT-RC) and green manuring (T-GM) on cropping system performance using agronomic, environmental and ecological indicators—to exemplify the need for multidimensional analysis to understand management implications for addressing environmental and agronomic challenges. We combined the results from 11 organic vegetable field trials conducted in seven European countries over a period of 2 years to test for general trends. Our results provide solid evidence that NT-RC management across different pedo-climatic conditions in Europe enhances the activity density of ground and rove beetles and improves both the potential energy recycling within the system and weed control. However, in NT-RC plots, lower cash crop yield and quality, energetic efficiency of production and activity density of spiders were observed compared to T-GM. Synthesis and applications. Multidimensional analyses using agronomic, environmental and ecological indicators are required to understand the implications of agricultural management in agroecosystem functioning. Introducing agroecological service crops combined with the use of no-till roller crimping is a promising strategy for improving agronomic performance (e.g. fewer weeds) and reducing environmental (e.g. increasing the potentially recyclable energy) and ecological (e.g. enhancing the activity density of beneficial taxa such as ground and rove beetles) impacts. However, our study also indicates a need for agronomic and environmental improvements while promoting a wider acceptance of this strategy.

Behavioural flexibility may play a relevant role during invasion of a new habitat. A typical example of behavioural flexibility favouring invasion success refers to changes in foraging behaviour. Here we provide data on changes in the foraging strategies of monk parakeets Myiopsitta monachus over a period of 17 years (2001–2017) in Barcelona city. During this time, consumption of food on the ground increased by more than 25 % and the consumption of anthropogenic food increased by 8 %. Detailed information about the food consumed is provided. Feeding on the ground and consumption of low plants allow parakeets to reach not only anthropogenic food but also crops, thereby increasing the risk of crop damage as the invasion evolves. Early detection of damage to crops is crucial in order to prevent further harm, and makes the precautionary principle highly relevant. Key words: Behavioural shift, Diet, Crop damage, Spillover, Longitudinal study

We studied the diversity of beetle families in watermelon fields in the palm grove of Zaatote at Ouargla (34º 54' N, 5º 20' E). The sampling method used was Barber pots as they allowed the largest number of captures of insects, regarding both individuals and species. Over the three years of the study (2016, 2017 and 2018), we identified 787 individuals from 12 taxonomic families. Throughout the sampling period, the Coccinellidae family was clearly dominant, with an Fc = 35.02 % in 2016, 36.2 % in 2017 and 34.34 % in 2018. The second most dominant family was Tenebrionidae with an Fc = 26.35 % in 2016, 30.04 % in 2017, and 33.33 % in 2018. Other families were poorly represented. In 2016, regarding their trophism, 18 species of beetles (30.91 %) were phytophagous and feed on the watermelon crop, while 26 species were predatory and decomposing auxiliaries. Se estudió la diversidad de familias de coleópteros en campos de cultivo de sandía situados en el palmeral de Zaatote (Ouargla) (34º 54' N,5º 20' E). El método de muestreo utilizado fueron botes de Barber, que permitieron el mayornúmero de capturas de insectos, tanto por lo que respecta a individuos como a especies.Durante los tres años del estudio (2016, 2017 y 2018) se identificaron 787 individuos pertenecientesa 12 familias taxonómicas. En todo el periodo de muestreo, la familia Coccinellidaefue claramente dominante con Fc = 35,02 % en 2016, 36,2 % en 2017 y 34,34 % en 2018,seguida de la familia Tenebrionidae con Fc = 26,35 % en 2016, 30,04 % en 2017 y 33,33 %en 2018. Las demás familias estaban muy poco representadas. En 2016, según su trofismo,18 especies de coleópteros (30,91 %) eran fitófagas y se alimentaban de los cultivosde sandía, mientras que 26 especies eran depredadoras y descomponedoras auxiliares. S'ha estudiat la diversitat de families de coleòpters encamps de síndria al palmeral de Zaatote a Ouargla (34º 54' N, 5º 20' E). El mètode demostreig aplicat va ser amb pots de Barber que van permetre el major nombre de capturesd'insectes, tant en individus com en espècies. Durant els tres anys d'estudi (2016, 2017 i2018), es van identificar 787 individus pertanyents a 12 famílies taxonòmiques. Durant tot elperíode de mostreig, la família Coccinellidae va ser clarament dominant amb Fc = 35,02 %el 2016, 36,2 % el 2017 i 34,34 % el 2018. En segona posició, la família Tenebrionidae ambel Fc = 26,35 % el 2016, el 30,04 % el 2017 i 33,33 % el 2018. La resta de famílies estavenmolt poc representades. En 2016, en funció del seu trofisme, 18 espècies de coleópters(30,91 %) eren fitòfagues i s'alimentaven dels cultius de sindria, mentre que 26 espècieseren depredadores i descomponedores auxiliars.

We studied the diversity of beetle families in watermelon fields in the palm grove of Zaatote at Ouargla (34º 54' N, 5º 20' E). The sampling method used was Barber pots as they allowed the largest number of captures of insects, regarding both individuals and species. Over the three years of the study (2016, 2017 and 2018), we identified 787 individuals from 12 taxonomic families. Throughout the sampling period, the Coccinellidae family was clearly dominant, with an Fc = 35.02 % in 2016, 36.2 % in 2017 and 34.34 % in 2018. The second most dominant family was Tenebrionidae with an Fc = 26.35 % in 2016, 30.04 % in 2017, and 33.33 % in 2018. Other families were poorly represented. In 2016, regarding their trophism, 18 species of beetles (30.91 %) were phytophagous and feed on the watermelon crop, while 26 species were predatory and decomposing auxiliaries. Se estudió la diversidad de familias de coleópteros en campos de cultivo de sandía situados en el palmeral de Zaatote (Ouargla) (34º 54' N,5º 20' E). El método de muestreo utilizado fueron botes de Barber, que permitieron el mayornúmero de capturas de insectos, tanto por lo que respecta a individuos como a especies.Durante los tres años del estudio (2016, 2017 y 2018) se identificaron 787 individuos pertenecientesa 12 familias taxonómicas. En todo el periodo de muestreo, la familia Coccinellidaefue claramente dominante con Fc = 35,02 % en 2016, 36,2 % en 2017 y 34,34 % en 2018,seguida de la familia Tenebrionidae con Fc = 26,35 % en 2016, 30,04 % en 2017 y 33,33 %en 2018. Las demás familias estaban muy poco representadas. En 2016, según su trofismo,18 especies de coleópteros (30,91 %) eran fitófagas y se alimentaban de los cultivosde sandía, mientras que 26 especies eran depredadoras y descomponedoras auxiliares. S'ha estudiat la diversitat de families de coleòpters encamps de síndria al palmeral de Zaatote a Ouargla (34º 54' N, 5º 20' E). El mètode demostreig aplicat va ser amb pots de Barber que van permetre el major nombre de capturesd'insectes, tant en individus com en espècies. Durant els tres anys d'estudi (2016, 2017 i2018), es van identificar 787 individus pertanyents a 12 famílies taxonòmiques. Durant tot elperíode de mostreig, la família Coccinellidae va ser clarament dominant amb Fc = 35,02 %el 2016, 36,2 % el 2017 i 34,34 % el 2018. En segona posició, la família Tenebrionidae ambel Fc = 26,35 % el 2016, el 30,04 % el 2017 i 33,33 % el 2018. La resta de famílies estavenmolt poc representades. En 2016, en funció del seu trofisme, 18 espècies de coleópters(30,91 %) eren fitòfagues i s'alimentaven dels cultius de sindria, mentre que 26 espècieseren depredadores i descomponedores auxiliars.

[eng] Rice belongs to the Poaceae family and Oryza genus. The genus Oryza comprehends 24 species, being 22 wild and 2 cultivated. These two cultivated species correspond to Oryza sativa, originated in Asia, nowadays cultivated and consumed worldwide, and Oryza glaberrima, originated in Africa, but cultivated and consumed limitedly in West Africa, both are diploid (2n=24) (Bernis & Pamies, 2006; Wei & Huang, 2019). Traditionally, Oryza sativa has been classified into two subspecies, indica and japonica. Molecular analyses, as well as biochemical and hybrid sterility analyses, point out at the separate domestication of Oryza rufipogon populations as the origin for these two subspecies (Garris et al., 2005; Rakshit et al., 2007; Wei et al., 2012), with a gene flow present from japonica to indica (Yang et al., 2012). Indica rice is usually long grained, less sticky and with a lower level of amylopectin than japonica rice, which is short grained and sticky. There are also phenotypical differences between these subspecies, for example, japonica plants are generally shorter, the leaves have a lighter color and shaper shape. Also, the tiller number is lower in japonica than in the indica plants (Wei & Huang, 2019). The O. sativa plant is a semiaquatic annual monocot grass although rice can live as perineal in the tropics (McLean et al., 2013). The plant has a height that varies from 80 to 150 centimeters depending on the variety and growing conditions (Bernis & Pamies, 2006), or even less in modern varieties. Its morphology varies according to the development stage, this being the vegetative phase or the reproductive phase. The vegetative phase includes the germination, the seedling and the tillering stage. The reproductive phase comprehends panicle initiation, also called heading, and flowering stages. As a food, rice contributes to the 20% of calories ingested worldwide (Kubo & Purevdorj, 2004), reaching half of the calories ingested daily in some areas (Counce et al., 2000). In terms of consumption, as well as production, Asia is the main continent (McLean et al., 2013). The rice production and consumption in Europe is minor compared to Asia. Despite that, rice holds an important sociocultural role since it is one of the basic foods of the Mediterranean diet. Some regions have developed famous rice dishes, like risotto in Italy or paella in Spain. The annual rice consumption per capita in Europe is 6-18 kilograms in the southern regions, and 3.5-5.5 kilograms in the northern regions (McLean et al., 2013). The main European producer is Italy, followed by Spain. These two countries hold more than 75% of the total rice production in Europe. Rice in Europe is also of ecological importance, due to the great biodiversity that inhabits and benefits from the paddy fields. Around 70-80% of rice cultivated in Europe are japonica varieties, and the rest indica (Bernis & Pamies, 2006; Ferrero, 2007). Agriculture is the most important bioeconomy sector in Spain, with a value of 43.8 million of euros in 2015 and coping the 50.9% employment of all bioeconomy sectors (Lániez & Periago, 2016). Rice mobilized 258.766 millions of euros in Spain in 2019 (MINECO, 2019). Thus, the studies dedicated to improving different aspects of the rice production in Spain are crucial. This thesis has made a multidisciplinary approach, from genetics to the field, in order to study Mediterranean rice varieties considering its actual applicability for the Spanish rice industry through three experimental approaches: (i) an improvement of the anther culture protocol for two Mediterranean temperate japonica varieties and two tropical japonica varieties trough the addition of additives to the media; (ii) testing the salt-tolerance of Saltol-introgressed varieties to select those that will help to fight the apple snails plague in the Ebro Delta; and (iii) a study of genetic and physicochemical aspects of the rice pearl in five Mediterranean varieties, an important feature in gastronomical terms.

Human land use threatens global biodiversity and compromises multiple ecosystem functions critical to food production. Whether crop yield–related ecosystem services can be maintained by a few dominant species or rely on high richness remains unclear. Using a global database from 89 studies (with 1475 locations), we partition the relative importance of species richness, abundance, and dominance for pollination; biological pest control; and final yields in the context of ongoing land-use change. Pollinator and enemy richness directly supported ecosystem services in addition to and independent of abundance and dominance. Up to 50% of the negative effects of landscape simplification on ecosystem services was due to richness losses of service-providing organisms, with negative consequences for crop yields. Maintaining the biodiversity of ecosystem service providers is therefore vital to sustain the flow of key agroecosystem benefits to society.

Coating seeds with biostimulants is among the promising approaches in crop production to increase crop tolerance to drought stress. In this study, we evaluated the potential of coating durum wheat seeds of the cultivar &lsquo, Karim&rsquo, with thyme essential oil on enhancing seed germination and seedling growth, and on plant growth promotion and induction of drought resistance. Coated seeds were pre-germinated, grown in hydroponics, and grown in pots under controlled well-watered and progressive water/nutrient stress conditions. Seed coating with thyme oil increased germination rate and enhanced seedling growth development in hydroponics. In the pot experiment, thyme oil increased, when well watered, root and shoot development, chlorophyll, nitrogen balance index (NBI), abscisic acid (ABA), anthocyanins and flavonoids in leaves, decreased nitrogen isotope composition (&delta, 15N) and increased carbon isotope composition (&delta, 13C) of shoots. Increasing water/nutrient stress in control plants induced higher accumulation of ABA and anthocyanins coupled with a transient decrease in chlorophyll and NBI, a decrease in shoot and root development, the Normalized Difference Vegetation Index (NDVI), shoot C content, &delta, 15N, and an increase in &delta, 13C, revealing the avoidance strategy adopted by the cultivar. Thyme oil had the potential to enhance the avoidance strategy by inducing roots elongation, reducing the loss of shoot and roots dry matter and chlorophyll, maintaining balanced NBI, an decreasing anthocyanins, flavonoids, and &delta, 13C via maintaining lower ABA-mediated-stomatal closure. Thyme oil increased shoot N content and &delta, 15N indicating preferential uptake of the 15N enriched NH4+. Coating seeds with thyme oil is suggested as a promising alternative approach to improve plant&rsquo, s water and nutrient status and to enhance drought resistance.

Septoria leaf blotch (SLB) is considered one of the most devastating diseases affecting global wheat production. Biostimulant application is among the modern approaches in plant protection to overcome the impact of SLB&rsquo, s fungicide resistance. In this manner, the effect of coating seeds with thyme essential oil or Paraburkholderia phytofirmansPsJN strain on SLB severity and yield components (spikes/m2, straw yield (SY), grain yield (GY) and thousand kernel weight (TKW)) were assessed under field conditions for 3 years. The effect on physiological traits and nitrogen and carbon isotope composition (&delta, 15Ngrain, &delta, 13Cgrain) and nitrogen and carbon content (Ngrain, Cgrain) of grains was assessed in one year of study. The increasing SLB severity decreased all yield components, increased &delta, 15Ngrain and Cgrain content and slightly decreased &delta, 13Cgrain as the resulting effect of Z.tritici inducing stomatal opening and leaf necrosis. Across the years, both treatments alleviated the SLB adverse impact by reducing SLB severity, increasing spikes/m2, SY, GY and TKW. Both treatments ameliorated grain quality by increasing Cgrain content and decreasing &delta, 13Cgrain and &delta, 15Ngrain. The difference between the performance of thyme oil or PsJN strain in terms of intensity and stability is discussed and considered to be linked to the different triggered systemic resistance and the associated amount of costs deriving from resource allocation towards defense processes.

Climate change is one of the primary culprits behind the restraint in the increase of cereal crop yields. In order to address its effects, effort has been focused on understanding the interaction between genotypic performance and the environment. Recent advances in unmanned aerial vehicles (UAV) have enabled the assembly of imaging sensors into precision aerial phenotyping platforms, so that a large number of plots can be screened effectively and rapidly. However, ground evaluations may still be an alternative in terms of cost and resolution. We compared the performance of red–green–blue (RGB), multispectral, and thermal data of individual plots captured from the ground and taken from a UAV, to assess genotypic differences in yield. Our results showed that crop vigor, together with the quantity and duration of green biomass that contributed to grain filling, were critical phenotypic traits for the selection of germplasm that is better adapted to present and future Mediterranean conditions. In this sense, the use of RGB images is presented as a powerful and low-cost approach for assessing crop performance. For example, broad sense heritability for some RGB indices was clearly higher than that of grain yield in the support irrigation (four times), rainfed (by 50%), and late planting (10%). Moreover, there wasn’t any significant effect from platform proximity (distance between the sensor and crop canopy) on the vegetation indexes, and both ground and aerial measurements performed similarly in assessing yield. This study was supported by the Spanish project AGL2016-76527-R “Fenotipeado En Trigo Duro: Bases Fisiológicas, Criterios De Selección Y Plataformas De Evaluación”, from the Ministerio Economía y Competitividad of the Spanish Government. A.G.-R. is a recipient of a FPI doctoral fellowship from the same institution. We also acknowledge the support from the Institut de Recerca de l’Aigua and the Universitat de Barcelona. J.L.A. acknowledges the funding support from ICREA, Generalitat de Catalunya, Spain.

Ear density is one of the most important agronomical yield components in wheat. Ear counting is time-consuming and tedious as it is most often conducted manually in field conditions. Moreover, different sampling techniques are often used resulting in a lack of standard protocol, which may eventually affect inter-comparability of results. Thermal sensors capture crop canopy features with more contrast than RGB sensors for image segmentation and classification tasks. An automatic thermal ear counting system is proposed to count the number of ears using zenithal/nadir thermal images acquired from a moderately high resolution handheld thermal camera. Three experimental sites under different growing conditions in Spain were used on a set of 24 varieties of durum wheat for this study. The automatic pipeline system developed uses contrast enhancement and filter techniques to segment image regions detected as ears. The approach is based on the temperature differential between the ears and the rest of the canopy, given that ears usually have higher temperatures due to their lower transpiration rates. Thermal images were acquired, together with RGB images and in situ (i.e., directly in the plot) visual ear counting from the same plot segment for validation purposes. The relationship between the thermal counting values and the in situ visual counting was fairly weak (R2 = 0.40), which highlights the difficulties in estimating ear density from one single image-perspective. However, the results show that the automatic thermal ear counting system performed quite well in counting the ears that do appear in the thermal images, exhibiting high correlations with the manual image-based counts from both thermal and RGB images in the sub-plot validation ring (R2 = 0.75–0.84). Automatic ear counting also exhibited high correlation with the manual counting from thermal images when considering the complete image (R2 = 0.80). The results also show a high correlation between the thermal and the RGB manual counting using the validation ring (R2 = 0.83). Methodological requirements and potential limitations of the technique are discussed. This work was supported by MINECO, Spain (project number AGL2016-76527-R) as the primary funding support for the research project; the project “Formación de Talento Humano de Alto Nivel” (project number BPIN 2013000100103) approved by the “Fondo de Ciencia, Tecnología e Innovación”, from the “Sistema General de Regalías”; and “Gobernación del Tolima—Universidad del Tolima, Colombia” as the sole funding source of the first author J.A.F.-G. Contribution of J.L.A. was supported in part by ICREA Academia, Generalitat de Catalunya, Spain.

[eng] Rice (Oryza sativa L.) is without doubt one of the major crops worldwide, as its consumption is continuously increasing, especially in low- and lower-middle-income countries where it is the most important staple. This cereal has been domesticated for a long time, result of which several species and varieties are now available. It was key during the green revolution when its production increased in more than 2-fold times, and in addition has a deep cultural background in all the regions where it is grown. Hence, it is of uttermost importance for researchers and breeders to broaden and expand the knowledge on this cereal on all the study and research areas, especially now that we are living in the 21st century, which is marked by climate change. This phenomenon is one of the most menacing as it will reduce the quantity and quality of arable land due to salinization of soil as well as water scarcity which is the single and most important factor that determines global crop yields. In this sense, this thesis addresses to three important topics on rice that will help researchers and breeders for the improvement of rice varieties in the forthcoming future: (i) Analysis of salinity tolerant rice plants subjected to high salt concentration through a combined approach of shotgun proteomics and physiological characterization for the identification of new key proteins involved in the tolerance to this stress. In this study we provide a huge database for future studies of the salinity-stress response in rice varieties harboring the Saltol region, as we detected more than 2000 proteins involved during the early stages of salinity stress in the shoots and roots of the FL478 rice line. Moreover, this study highlights the importance of examining both the shoots and roots because their salinity tolerance traits are different and respond to different requirements of the rice plant. Finally, the information presented here expands our knowledge on adaptive processes under high salinity in rice plants and, notably, in rice roots. (ii) Phytohormones analysis in dwarf varieties through a broad phytohormone profiling method developed during this thesis for the characterization of phytohormone levels during the development of plants with contrasting heights that will allow to have more information for developing new dwarf mutant varieties. In this work, we reported that GA19 seems to have a crucial role in gibberellin availability in rice as its levels were much higher than all the other gibberellins in all tissues. In addition, it has been demonstrated that the GA20ox-2 mutation is not the only factor affecting height in rice, as a mutated variety had an increased growth during the half of its development period. Finally, we established for the first time a simple and broad phytohormone extraction and detection protocol that allows to identify 13 gibberellins and ABA, JA and IAA in several tissues at different phenological stages. (iii) Improvement and enhancement of anther culture protocols in rice for obtaining higher rates of stabilized green double haploid plants using different cold-pretreatments and additives in the growing media such as hormones and antimitotics in the growing media for their subsequent commercialization. It was evidenced that the best cold-pretreatment was 10ºC for 9 days, and that colchicine addition greatly enhances the production of green double haploid plantlets. Moreover, we have introduced for the first time a post-anther culture treatment with good prospects. Finally, several of the rice lines produced were assayed in rice paddy fields where they displayed good agronomical behavior., [spa] El arroz (Oryza sativa L.) es sin duda uno de los principales cultivos del mundo, especialmente en países en vías de desarrollo donde es el alimento básico, teniendo además un importante componente cultural. Fue clave en la revolución verde cuando su producción aumentó más del doble. En el siglo 21 marcado por el cambio climático, se verá reducida la cantidad y calidad de las tierras cultivables debido a la salinización del suelo y la escasez de agua. Por tanto, es de gran importancia para los investigadores y mejoradores ampliar el conocimiento que se tiene sobre este cereal en todas las áreas de estudio. En este sentido, esta tesis abordó tres temas importantes referentes a este cereal: (i) Un estudio del proteoma, de la parte aérea y radicular, de plantas de arroz tolerantes a la salinidad sometidas a una alta concentración de sal con el objetivo de identificar de nuevas proteínas clave involucradas en la tolerancia a este estrés. Proporcionamos una gran base de datos, más de 200 proteínas involucradas en este estrés y destacamos la importancia de las raíces para la tolerancia a este estrés. (ii) Análisis de fitohormonas en variedades enanas a través de un amplio y rápido método desarrollado durante esta tesis que permite, por primera vez en arroz, la extracción y detección de fitohormonas que posibilida la identificación de 13 giberelinas y ABA, JA e IAA en varios tejidos en diferentes etapas fenológicas. Se observó que la GA19 parece tener un papel crucial en la disponibilidad de giberelinas en el arroz, ya que sus niveles son los más elevados en todos los tejidos. La mutación GA20ox-2 no es el único factor que afecta la altura ya que la variedad mutada alcanza la altura de variedades wild-type. (iii) Por último, se reportan dos métodos de aumento de la eficiencia del protocolo de cultivo de anteras, técnica muy útil para la obtención de plantas de arroz dihaploides estables. El aumento del rendimiento se debió a nuevos pretratamientos de frío, así como la modificación de los medios de cultivo mediante diferentes concentraciones de hormonas y colchicina. Se introdujo, por primera vez, un tratamiento de diploidización para plantas haploides.

Ancient civilisations depended heavily on natural fuel resources for a wide array of activities, and this had an impact on such resources that can be traced in the archaeological record. At its urban apex, the populations of the Indus Civilisation (2600–1900 BC) produced a wide range of objects and crafts, several of which involved highly specialised pyrotechnology. In the wake of increasing aridity and a period of weakened monsoon rainfall that affected South Asia from 2100 BC, these activities potentially put pressure on the natural resource base that may have had to be counterbalanced by differentiation in fuel use. The combined analysis of archaeobotanical and geoarchaeological remains from four Indus urban phase archaeological sites, has enable an assessment of the mechanisms through which people exploited wood, and diversified their fuel resources to adapt to the arid to semi-arid environments in which they lived. The combined use of local wood species with alternative fuels, such as dung and crop-processing leftovers, are evidence for resilient socio-ecological practices during the 700 years of Indus urbanism and perhaps beyond. The research was funded by AHRC Doctoral grant (2007/131224), St John’s College [no grant number], Cambridge European Trust (300469695) and The University of Cambridge (Isbel-Fletcher Garden Fund [no grant number], Smuts Memorial Fund [S2007/E2007], and Anthony Wilkin Fund [no grant number]).

Background The number of ears per unit ground area (ear density) is one of the main agronomic yield components in determining grain yield in wheat. A fast evaluation of this attribute may contribute to monitoring the efficiency of crop management practices, to an early prediction of grain yield or as a phenotyping trait in breeding programs. Currently the number of ears is counted manually, which is time consuming. Moreover, there is no single standardized protocol for counting the ears. An automatic ear-counting algorithm is proposed to estimate ear density under field conditions based on zenithal color digital images taken from above the crop in natural light conditions. Field trials were carried out at two sites in Spain during the 2014/2015 crop season on a set of 24 varieties of durum wheat with two growing conditions per site. The algorithm for counting uses three steps: (1) a Laplacian frequency filter chosen to remove low and high frequency elements appearing in an image, (2) a Median filter to reduce high noise still present around the ears and (3) segmentation using Find Maxima to segment local peaks and determine the ear count within the image. Results The results demonstrate high success rate (higher than 90%) between the algorithm counts and the manual (image-based) ear counts, and precision, with a low standard deviation (around 5%). The relationships between algorithm ear counts and grain yield was also significant and greater than the correlation with manual (field-based) ear counts. In this approach, results demonstrate that automatic ear counting performed on data captured around anthesis correlated better with grain yield than with images captured at later stages when the low performance of ear counting at late grain filling stages was associated with the loss of contrast between canopy and ears. Conclusions Developing robust, low-cost and efficient field methods to assess wheat ear density, as a major agronomic component of yield, is highly relevant for phenotyping efforts towards increases in grain yield. Although the phenological stage of measurements is important, the robust image analysis algorithm presented here appears to be amenable from aerial or other automated platforms. Electronic supplementary material The online version of this article (10.1186/s13007-018-0289-4) contains supplementary material, which is available to authorized users.

Dorsoventrality in isobilateral wheat leaves may affect the reflected radiation spectrum and its accuracy in predicting physiological and agronomical traits under field conditions, The effects of leaf dorsoventrality and its interaction with environmentally induced changes in the leaf spectral response are still poorly understood, particularly for isobilateral leaves. We investigated the spectral performance of 24 genotypes of field-grown durum wheat at two locations under both rainfed and irrigated conditions. Flag leaf reflectance spectra in the VIS-NIR-SWIR (visible–near-infrared–short-wave infrared) regions were recorded in the adaxial and abaxial leaf sides and at the canopy level, while traits providing information on water status and grain yield were evaluated. Moreover, leaf anatomical parameters were measured in a subset of five genotypes. The spectral traits studied were more affected by the leaf side than by the water regime. Leaf dorsoventral differences suggested higher accessory pigment content in the abaxial leaf side, while water regime differences were related to increased chlorophyll, nitrogen, and water contents in the leaves in the irrigated treatment. These variations were associated with anatomical changes. Additionally, leaf dorsoventral differences were less in the rainfed treatment, suggesting the existence of leaf-side-specific responses at the anatomical and biochemical level. Finally, the accuracy in yield prediction was enhanced when abaxial leaf spectra were employed. We concluded that the importance of dorsoventrality in spectral traits is paramount, even in isobilateral leaves.

The dependence on tillage in organic agriculture has raised questions regarding soil management in organic systems. Recently, Agro-ecological Service Crops (ASC) and roller crimper (RC) technology have attracted attention in organic farming circles. ASC are sown before cash crops to provide benefits for agro-ecosystem services. RC permits the creation of a mulch on the soil surface consisting of ASC plant material with no need for tillage. Studies carried out in the USA, Canada and Latin America on RC reveal some of the potential benefits and drawbacks of this technology. However, only a few such studies have taken place in European agroecosystems. The objective of the SoilVeg project (ERA-Net CORE Organic Plus) is to study RC under European environmental and agronomic conditions. This paper shows how sowing ASC before autumn-winter cash crops and the termination strategy affect (i) the abundance of soil arthropods and (ii) the diversity of both pest and beneficial insects in Italy and Spain. Roller crimper, agro-ecological service crops, ground-dwelling arthropods, aphids, parasitoids, aphidophagous predators

Cosmopolitan pests such as Brevicoryne brassicae, Lipaphis pseudobrassicae, and Myzus persicae (Aphididae) cause significant damage to Brassicaceae crops. Assessment of the important biotic and abiotic factors that regulate these pests is an essential step in the development of effective Integrated Pest Management programs for these aphids. This study evaluated the influence of leaf position, precipitation, temperature, and parasitism on populations of L. pseudobrassicae, M. persicae, and B. brassicae in collard greens fields in the Triângulo Mineiro region (Minas Gerais state), Brazil. Similar numbers of B. brassicae were found on all parts of the collard green plants, whereas M. persicae and L. pseudobrassicae were found in greatest numbers on the middle and lower parts of the plant. While temperature and precipitation were positively related to aphid population size, their effects were not accumulative, as indicated by a negative interaction term. Although Diaeretiella rapae was the main parasitoid of these aphids, hyperparasitism was dominant; the main hyperparasitoid species recovered from plant samples was Alloxysta fuscicornis. Parasitoids seem to have similar distributions on plants as their hosts. These results may help predict aphid outbreaks and gives clues for specific intra-plant locations when searching for and monitoring aphid populations.

Understanding ecosystem functioning in a farmland context by considering the variety of ecological strategies employed by arthropods is a core challenge in ecology and conservation science. We adopted a functional approach in an assessment of the relationship between three functional plant groups (grasses, broad-leaves and legumes) and the arthropod community in winter wheat fields in a Mediterranean dryland context. We sampled the arthropod community as thoroughly as possible with a combination of suction catching and flight-interception trapping. All specimens were identified to the appropriate taxonomic level (family, genus or species) and classified according to their form of feeding: chewing-herbivores, sucking-herbivores, flower-consumers, omnivores, saprovores, parasitoids or predators. We found, a richer plant community favoured a greater diversity of herbivores and, in turn, a richness of herbivores and saprovores enhanced the communities of their natural enemies, which supports the classical trophic structure hypothesis. Grass cover had a positive effect on sucking-herbivores, saprovores and their natural enemies and is probably due to grasses' ability provide, either directly or indirectly, alternative resources or simply by offering better environmental conditions. By including legumes in agroecosystems we can improve the conservation of beneficial arthropods like predators or parasitoids, and enhance the provision of ecosystem services such as natural pest control. Keywords: functional approach, plant-arthropod interaction, biological control, legumes, ecosystem services, 49 insect functional traits.

Understanding ecosystem functioning in a farmland context by considering the variety of ecological strategies employed by arthropods is a core challenge in ecology and conservation science. We adopted a functional approach in an assessment of the relationship between three functional plant groups (grasses, broad-leaves and legumes) and the arthropod community in winter wheat fields in a Mediterranean dryland context. We sampled the arthropod community as thoroughly as possible with a combination of suction catching and flight-interception trapping. All specimens were identified to the appropriate taxonomic level (family, genus or species) and classified according to their form of feeding: chewing-herbivores, sucking-herbivores, flower-consumers, omnivores, saprovores, parasitoids or predators. We found, a richer plant community favoured a greater diversity of herbivores and, in turn, a richness of herbivores and saprovores enhanced the communities of their natural enemies, which supports the classical trophic structure hypothesis. Grass cover had a positive effect on sucking-herbivores, saprovores and their natural enemies and is probably due to grasses' ability provide, either directly or indirectly, alternative resources or simply by offering better environmental conditions. By including legumes in agroecosystems we can improve the conservation of beneficial arthropods like predators or parasitoids, and enhance the provision of ecosystem services such as natural pest control. Keywords: functional approach, plant-arthropod interaction, biological control, legumes, ecosystem services, 49 insect functional traits.

Sweet cherry, a non-climacteric fruit, is usually cold-stored during post-harvest to prevent over-ripening. The aim of the study was to evaluate the role of abscisic acid (ABA) on fruit growth and ripening of this fruit, considering as well its putative implication in over-ripening and effects on quality. We measured the endogenous concentrations of ABA during the ripening of sweet cherries (Prunus avium L. var. Prime Giant) collected from orchard trees and in cherries exposed to 4°C and 23°C during 10 days of post-harvest. Furthermore, we examined to what extent endogenous ABA concentrations were related to quality parameters, such as fruit biomass, anthocyanin accumulation and levels of vitamins C and E. Endogenous concentrations of ABA in fruits increased progressively during fruit growth and ripening on the tree, to decrease later during post-harvest at 23°C. Cold treatment, however, increased ABA levels and led to an inhibition of over-ripening. Furthermore, ABA levels positively correlated with anthocyanin and vitamin E levels during pre-harvest, but not during post-harvest. We conclude that ABA plays a major role in sweet cherry development, stimulating its ripening process and positively influencing quality parameters during pre-harvest. The possible influence of ABA preventing over-ripening in cold-stored sweet cherries is also discussed.

[cat] La disponibilitat de la majoria dels fongs micorízics comestibles depèn de la seva fructificació natural. La formació de bolets està relacionada amb les característiques de l'hàbitat i les condicions climàtiques, però aquestes dades no expliquen ni la dinàmica de la fructificació ni del miceli d’aquests fongs. L’establiment de plantacions a partir de plantes micorizades pot ser una alternativa per a l'obtenció de fongs comestibles ectomicorízics. El progrés de les noves tecnologies en la biologia molecular han permès el desenvolupament, implementació i ús de tècniques per a la traçabilitat dels fongs ectomicorízics comestibles. A la tesi s'ha demostrat que la PCR en temps real, amb el disseny d'oligonucleòtids específics per a la detecció i quantificació de miceli extraradical, ens permet determinar la concentració de miceli present al sòl tant a boscos com a plantacions. La micorizació de plantes amb espècies del complex Boletus edulis s'ha aconseguit en condicions de cultiu pur. S’han dissenyat encebadors i sondes específics per l’amplificació de B. edulis i Tuber melanosporum per PCR en temps real. S’ha estudiat la dinàmica estacional del miceli extraradical, les ectomicorizes i la producció de B. edulis i Lactarius deliciosus, a dos boscos de Sòria. També s’ha quantificat el miceli extraradical de Rhizopogon roseolus (a dues plantacions) i de T. melanosporum (a una plantació), des del seu establiment. Per altra banda s’ha quantificat el miceli extraradical de T. melanosporum en una tofonera natural i en set plantacions (d’uns 20 anys). Finalment, s’ha analitzat l'estructura genètica d’una població de T. melanosporum a una plantació productiva, determinat la distribució dels tipus de compatibilitat al sòl, i els genotips de micorizes i ascocarps fent us de marcadors microsatèl•lits. No s'ha trobat relació directa entre les quantitats de miceli del sòl i la producció per cap de les espècies estudiades, però s’ha correlacionat positivament les estructures vegetatives de B. edulis, R. roseolus i T. melanosporum. Els resultats obren la possibilitat d'utilitzar la quantificació de miceli del sòl per PCR en temps real com un bon indicador de la colonització de les arrels en condicions de camp. Les quantitats de miceli extraradical de B. edulis, L. deliciosus i R. roseolus i les micorizes de T. melanosporum s’han correlacionat amb diferents paràmetres climàtics. Finalment, ha estat possible determinar la distribució dels diferents genotips de T. melanosporum a una plantació, on es va trobar una estructura genètica espacial amb un patró de distribució no aleatori, resultant en zones de camp colonitzat per genets que compartien els mateixos tipus de compatibilitat., [eng] The availability of most edible ectomycorrhizal mushrooms depends on their natural fructification. Therefore, mycorrhizal plant production could be an alternative for obtaining ectomycorrhizal edible fungi. The first step to establish a plantation for a certain species of mushrooms is the production of plants, inoculated with the fungus, in order to be outplanted to field. The mycorrhization of plants with species of the Boletus edulis complex has been achieved under pure culture synthesis conditions. The production of B. edulis mycorrhizal plants under nursery conditions could be achieved by acclimation of in vitro-produced mycorrhizal plants, but needs still more research to determine an appropriate procedure. Sporocarp formation of these fungi is linked to habitat characteristics and climate conditions, but these data alone do not explain all the trends of fungal fruiting and dynamics. It could be hypothesized that the amount of soil mycelia could also be related to the production of carpophores. Progress of new technologies in molecular biology and the availability of fungal genomes have led to the development, implementation and use of techniques for the traceability of edible ectomycorrhizal fungi. Through the thesis it has been demonstrated that the real- time PCR technique, with the design of specific oligonucleotides for the detection and quantification of extraradical mycelium in soil, allows us to determine the concentration of soil mycelium in forests and plantations, increasing detection limits over conventional PCR. Specific primers and probes have been designed for B. edulis and Tuber melanosporum for real-time PCR amplification, allowing the traceability of these fungal species in the controlled production of edible mycorrhizal mushrooms. The annual belowground dynamics of extraradical soil mycelium, ectomycorrhizal root tips and sporocarp production of two ectomycorrhizal fungi, B. edulis and Lactarius deliciosus, have been studied in two different pine forests (Pinar Grande and Pinares Llanos, respectively) in Soria in permanent plots. Quantification of extraradical mycelium of Rhizopogon roseolus x Pinus pinea plantations (two in Cabils) and of T. melanosporum x Quercus ilex plantation (one in Cerc), in Catalunya has been carried out from its establishment until 24 or 48 months. T. melanosporum extraradical mycelium has also been quantified by real-time PCR in a natural truffle ground and in seven truffle orchards (around 20 years old) established in Tierra Estella and Valdorba sites (Navarra). Finally, the spatial genetic structure of T. melanosporum population was analyzed in a productive orchard (France). The distribution of the two T. melanosporum mating types was monitored in the soil. Ectomycorrhizas and ascocarps were mapped and genotyped using simple sequence repeat markers and the mating type locus and their genetic profiles were compared. No direct relationships were found between soil mycelium amounts and sporocarp production for any of the studied fungal species, but it was possible to obtain positive correlations between vegetative structures (ectomycorrhiza and extraradical mycelium) for B. edulis, R. roseolus and T. melanosporum. The results obtained open the possibility of using quantification of soil mycelium by real-time PCR as a good indicator for root colonization in field conditions (in natural areas or in manmade orchards), especially when a nondestructive sampling or less time consuming analysis were required. The extraradical mycelial amounts of B. edulis, L. deliciosus and R. roseolus and T. melanosporum mycorrhizas were correlated with climate parameters as temperature, rainfall, solar radiation, relative humidity and evapotranspiration. Moreover, it has been possible to map the distribution of different T. melanosporum genotypes trough the traceability of ascocarps, ectomycorrhizas and soil samples. A pronounced spatial genetic structure was found. A nonrandom distribution pattern of the T. melanosporum was observed, resulting in field patches colonized by genets that shared the same mating types.

160 Pags., [EN] This work studied the effects of long term adoption of tillage practices (NT, no-tillage; MT, minimum tillage; CT, conventional tillage) and nitrogen (N) fertilization level (zero; medium, 60 kg N ha-1; high, 120 kg N ha-1) on the SOC balance and the content of SOC. Below- and above-ground C inputs were quantified during three growing seasons, 10 to 13 years after the establishment of the experiment. During the same period, soil CO2 flux was evaluated, together with the assessment of its components and the determination of C outputs. During the study period, C inputs were increased under NT and with medium and high N fertilization. Meanwhile C outputs were increased under NT, but less affected by N fertilization. Determination of the stock of SOC at the end of the evaluation period suggests that increased C outputs under NT were offset with increased C inputs, allowing the content of SOC to increase by 4.3 and 3.9 Mg C ha-1 in comparison to MT and CT respectively. Long-term medium and high N fertilization increased the stock of SOC by 3.4 and 4.5 Mg C ha-1 in contrast to unfertilized plots. Long-term adoption of conservation tillage practices (no-tillage) together with adequate N fertilizer use, proved to be effective tools to improve sustainability of semiarid Mediterranean drylands and to store C in the soil., [ES] Este trabajo estudió los efectos de la adopción a largo plazo de sistemas de laboreo (NT, no-laboreo; MT, laboreo minimo; CT, laboreo convencional) y del nivel de fertilización nitrogenada (cero; medio, 60 kg N ha-1; alto, 120 kg N ha-1) en el balance de C del suelo y el contenido de SOC. Se cuantificaron las entradas de C en los residuos de la parte aérea y subterránea del cultivo durante tres ciclos de cultivo, entre 10 y 13 años después del establecimiento del experimento. Durante este mismo período, se evaluó el flujo de CO2 del suelo, junto con el estudio de sus componentes y la determinación de las salidas de C. Durante el período de estudio, las entradas de C aumentaron bajo NT y con niveles medios y altos de fertilización nitrogenada. Simultáneamente las salidas de C aumentaron bajo NT y fueron ligeramente afectadas por la fertilización nitrogenada. La determinación del contenido de SOC al final del período de estudio, sugiere que el aumento de las salidas de C fue compensado con mayores entradas de C, permitiendo que el contenido de SOC aumentara en 4.3 y 3.9 Mg C ha-1 bajo NT con respecto a MT y CT. Niveles medios y altos de fertilización nitrogenada aumentaron el contenido de SOC en 3.4 y 4.5 Mg C ha-1 con respecto al contenido en las parcelas no fertilizadas. La adopción a largo plazo de prácticas de laboreo de conservación (no-laboreo o siembra directa), junto con el uso adecuado de la fertilitzación nitrogenada demostraron ser herramientas para mejorar la sostenibilidad de los secanos semiáridos Mediterráneos, y almacenar C en el suelo., [CA] Aquest treball estudia els efectes de l’adopció a llarg termini de sistemes de conreu (NT, sembra directa; MT, mínim conreu CT, conreu convencional) i del nivell de fertilizació nitrogenada (zero; mitjà, 60 kg N ha-1; alt, 120 kg N ha-1) al balanç de C del sòl i el contingut de SOC. Es van quantificar les entrades de C en els residus del cultiu (foliar i radicular) durant tres cicles de cultiu, entre 10 i 13 anys després del establiment de l’experiment. Durant aquest període, es va avaluar el flux de CO2 del sòl, juntament amb l’estudi dels seus components i la determinació de les sortides de C. Durant el període de estudi, les entrades de C van augmentar amb NT i amb nivells mitjos i alts de fertilització nitrogenada. Simultàniament les sortides de C van augmentar amb NT i van ser lleugerament afectades per la fertilització nitrogenada. La determinació del contingut de SOC al final del període d´estudi, suggereix que l´augment de les entrades C inputs estigués compensat amb majors entrades de C, permetent que el contingut de SOC augmentara finalment 4.3 i 3.9 Mg C ha-1 sota NT repecte a MT i CT. Nivells mitjans i alts de fertilització nitrogenada augmentaren el contingut de SOC en 3.4 i 4.5 Mg C ha-1 respecte al contingut a les parcel•les no fertilitzades. L´adopció a llarg termini de pràctiques de conreu de conservació (sembra directa), juntament amb l’ús adequat de la fertilització nitrogenada van demostrar ser eines per a millorar la sostenibilitat dels nostres secans, i emmagatzemar C al sòl., To the Spanish Ministry of Science and Innovation, Comision Interministerial de Ciencia y Tecnologia of Spain (Grants AGL 2004-07763-C02-02 and AGL2007- 66320-CO2-02/AGR), for sponsoring a grant for my doctorate studies.

Greenhouse climate control is extremely important in order to foster crop development and avoid plant diseases. Among the most important variables to control, there are temperature, humidity, PAR radiation and CO2, all of them are di cult to manage. This work aims to study greenhouse climate during night-time condi- tions, the same greenhouse case was analysed through a macro-element energy model (Chapter 2), a CFD (Computational Fluid dynamics) model (chapter 3) and experimental measures (chapter 4). Finally the three methods were compared and discussed (chapter 5).

En este trabajo se investiga la persistencia de las estimaciones puntuales subjetivas de rendimientos en cultivos anua- les realizadas por un amplio grupo de agricultores. La persistencia en el tiempo es una condición necesaria para la co- herencia y la confiabilidad de las estimaciones subjetivas de variables aleatorias. Los sujetos entrevistados estimaron valores puntuales de rendimientos de cultivos anuales (rendimientos medio, mayor, mínimo y más frecuente). Se han encontrado diferencias relativas poco importantes en todas las variables, excepto en los rendimientos mínimos, donde existe una alta dispersión. Los resultados son interesantes para estimar la adecuación de las técnicas de estimación de probabilidades subjetivas para ser utilizadas en los sistemas de ayuda en la toma de decisiones en agricultura. The aim of this research was to investigate the persistence of annual crop yield point value subjective estimates, elicited from a series of interviews carried out on a wide group of farmers. Time persistence is a necessary condition of coherence and reliability in subjective crop yield probability estimation. The interviewed subjects gave estimates for point crop yield (mean, highest, most frequent and lowest possible). Limited relative differences for all variables were found, except for the lowest possible crop yield estimates, which had a broad dispersion. The results are deemed valuable in order to determine the level of trust in the techniques applied in obtaining data, and in their effectiveness in designing a farm decision support system (DSS) to enhance the outcome of farmers’ decision making.

Mechanistic soil-crop models have become indispensable tools to investigate the effect of management practices on the productivity or environmental impacts of arable crops. Ideally these models may claim to be universally applicable because they simulate the major processes governing the fate of inputs such as fertiliser nitrogen or pesticides. However, because they deal with complex systems and uncertain phenomena, site-specific calibration is usually a prerequisite to ensure their predictions are realistic. This statement implies that some experimental knowledge on the system to be simulated should be available prior to any modelling attempt, and raises a tremendous limitation to practical applications of models. Because the demand for more general simulation results is high, modellers have nevertheless taken the bold step of extrapolating a model tested within a limited sample of real conditions to a much larger domain. While methodological questions are often disregarded in this extrapolation process, they are specifically addressed in this paper, and in particular the issue of models a priori parameterisation. We thus implemented and tested a standard procedure to parameterize the soil components of a modified version of the CERES models. The procedure converts routinely-available soil properties into functional characteristics by means of pedo-transfer functions. The resulting predictions of soil water and nitrogen dynamics, as well as crop biomass, nitrogen content and leaf area index were compared to observations from trials conducted in five locations across Europe (southern Italy, northern Spain, northern France and northern Germany). In three cases, the model’s performance was judged acceptable when compared to experimental errors on the measurements, based on a test of the model’s root mean squared error (RMSE). Significant deviations between observations and model outputs were however noted in all sites, and could be ascribed to various model routines. In decreasing importance, these were: water balance, the turnover of soil organic matter, and crop N uptake. A better match to field observations could therefore be achieved by visually adjusting related parameters, such as field-capacity water content or the size of soil microbial biomass. As a result, model predictions fell within the measurement errors in all sites for most variables, and the model’s RMSE was within the range of published values for similar tests. We conclude that the proposed a priori method yields acceptable simulations with only a 50% probability, a figure which may be greatly increased through a posteriori calibration. Modellers should thus exercise caution when extrapolating their models to a large sample of pedo-climatic conditions for which they have only limited information.