Variability of Arundo donax growth in dry-farming as a function of soil properties

Arundo donax L., commonly known as giant reed or arundo, is a perennial rhizomatous grass that has been studied since the decade of 1980 for bioenergy. In the Mediterranean region -characterised by dry and hot summers- arundo is usually grown with the support of irrigation. However, there is evidence that this plant species can tolerate dry-farming conditions once the crop is fully established. In this work the variation observed in plant growth of a 5-year-old arundo crop when the management changed from irrigated to dry-farming, is assessed. The hypothesis underlying this work was that punctual variations of soil properties might be responsible for the differences observed in plant growth

Climate Change Impacts on Maize and Dry Bean Yields of smallholder farmers in Honduras

The rotation maize and dry bean provides the main food supply of smallholder farmers in Honduras. Crop model assessment of climate change impacts (2070?2099 compared to a 1961?1990 baseline) on a maize?dry bean rotation for several sites across a range of climatic zones and elevations in Honduras. Low productivity systems, together with an uncertain future climate, pose a high level of risk for food security. The cropping systems simulation dynamic model CropSyst was calibrated and validated upon field trail site at Zamorano, then run with baseline and future climate scenarios based upon general circulation models (GCM) and the ClimGen synthetic daily weather generator. Results indicate large uncertainty in crop production from various GCM simulations and future emissions scenarios, but generally reduced yields at low elevations by 0 % to 22 % in suitable areas for crop production and increased yield at the cooler, on the hillsides, where farming needs to reduce soil erosion with conservation techniques. Further studies are needed to investigate strategies to reduce impacts and to explore adaptation tactics.

Seed Dispersal Spectrum of Woody Species in South Ecuadorian Dry Forests: Environmental Correlates and the Effect of Considering Species Abundance

This study examines the seed dispersal spectrum of the tropical dry forests of Southern Ecuador, in an effort to contribute to the knowledge of the complex dynamics of tropical dry forests. Seed dispersal spectrum was described for a total number of 160 species. Relationships of dispersal syndromes with plant growth form and climatic seasonality were explored. For a subset of 97 species, we determined whether dispersal spectrum changes when species abundance, in addition to species number, is taken into account. The same subset was used to relate dispersal syndromes with the environmental conditions. Zoochorous species dominated in the studied community. When considering the individual abundance of each species, however, anemochory was the prevalent dispersal syndrome. We found a significant difference in the frequency of dispersal syndromes among plant growth forms, with epizoochory only occurring in shrub species. The dispersal spectrum was dependent on climatic seasonality. The largest proportion of anemochorous species fructified during the dry season, while zoochorous diaspores dominated during the rainy season. A fourth-corner analysis indicated that the seed dispersal spectrum of Southern Ecuador dry forests is controlled by environmental conditions such as annual precipitation, annual temperature range or topography. Our results suggest that spatio-temporal changes in the environmental conditions may affect important ecological processes for dispersal. Thus, the predominance of one syndrome or another may depend on the spatial variation of environmental conditions.

A waypoint-based mission planner for a farmland coverage with an aerial robot - a precision farming tool

Remote sensing (RS) with aerial robots is becoming more usual in every day time in Precision Agriculture (PA) practices, do to their advantages over conventional methods. Usually, available commercial platforms providing off-the-shelf waypoint navigation are adopted to perform visual surveys over crop fields, with the purpose to acquire specific image samples. The way in which a waypoint list is computed and dispatched to the aerial robot when mapping non empty agricultural workspaces has not been yet discussed. In this paper we propose an offline mission planner approach that computes an efficient coverage path subject to some constraints by decomposing the environment approximately into cells. Therefore, the aim of this work is contributing with a feasible waypoints-based tool to support PA practices

Comparative study of Fusarium communities from soil and rhizoplane of melon plants from tropical farming soils.

Fifty-nine rhizospheric soil samples from twenty different melon farms of Guatemala and Honduras were analysed to study the Fusarium species present in the soil and those developing on roots surfaces.

Sustainability of irrigated farming systems in a Tunisian region: A recursive stochastic programming analysis

The aim of this study was to evaluate the sustainability of farm irrigation systems in the Cébalat district in northern Tunisia. It addressed the challenging topic of sustainable agriculture through a bio-economic approach linking a biophysical model to an economic optimisation model. A crop growth simulation model (CropSyst) was used to build a database to determine the relationships between agricultural practices, crop yields and environmental effects (salt accumulation in soil and leaching of nitrates) in a context of high climatic variability. The database was then fed into a recursive stochastic model set for a 10-year plan that allowed analysing the effects of cropping patterns on farm income, salt accumulation and nitrate leaching. We assumed that the long-term sustainability of soil productivity might be in conflict with farm profitability in the short-term. Assuming a discount rate of 10% (for the base scenario), the model closely reproduced the current system and allowed to predict the degradation of soil quality due to long-term salt accumulation. The results showed that there was more accumulation of salt in the soil for the base scenario than for the alternative scenario (discount rate of 0%). This result was induced by applying a higher quantity of water per hectare for the alternative as compared to a base scenario. The results also showed that nitrogen leaching is very low for the two discount rates and all climate scenarios. In conclusion, the results show that the difference in farm income between the alternative and base scenarios increases over time to attain 45% after 10 years.

Evolution not revolution of farming systemswill best feed and green the world

The challenge to properly feed a world population of 9.2 billion by 2050, that must be achieved on essentially currently cropped area, requires that food production be increased by 70%. This large increase can only be achieved by combinations of greater crop yields and more intensive cropping adapted to local conditions and availability of inputs. Farming systems are dynamic and continuously adapt to changing ecological, environmental and social conditions, while achieving greater production and resource-use efficiency by application of science and technology. This article argues that the solution to feed and green the world in 2050 is to support this evolution more strongly by providing farmers with necessary information, inputs, and recognition. There is no revolutionary alternative. Proposals to transform agriculture to low-input and organic systems would, because of low productiv- ity, exacerbate the challenge if applied in small part, and ensure failure if applied more widely. The challenge is, however, great. Irrigation, necessary to increase cropping intensity in many areas cannot be extended much more widely than at present, and it is uncertain if the current rate of crop yield increase can be maintained. Society needs greater recognition of the food-supply problem and must increase funding and support for agricultural research while it attends to issues of food waste and over consumption that can make valuable reductions to food demand from agriculture

Dry cooling with night cool storage to enhance solar power plants performance in extreme conditions areas

Solar thermal power plants are usually installed in locations with high yearly average solar radiation, often deserts. In such conditions, cooling water required for thermodynamic cycles is rarely available. Moreover, when solar radiation is high, ambient temperature is very high as well; this leads to excessive condensation temperature, especially when air-condensers are used, and decreases the plant efficiency. However, temperature variation in deserts is often very high, which drives to relatively low temperatures during the night. This fact can be exploited with the use of a closed cooling system, so that the coolant (water) is chilled during the night and store. Chilled water is then used during peak temperature hours to cool the condenser (dry cooling), thus enhancing power output and efficiency. The present work analyzes the performance improvement achieved by night thermal cool storage, compared to its equivalent air cooled power plant. Dry cooling is proved to be energy-effective for moderately high day–night temperature differences (20 °C), often found in desert locations. The storage volume requirement for different power plant efficiencies has also been studied, resulting on an asymptotic tendency.

Heterogeneity of atmosfpheric ammonia at the landscape scale and consequences for environmental impact assessment.

We examined the consequences of the spatial heterogeneity of atmospheric ammonia (NH3) by measuring and modelling NH3 concentrations and deposition at 25 m grid resolution for a rural landscape containing intensive poultry farming, agricultural grassland, woodland and moorland. The emission pattern gave rise to a high spatial variability of modelled mean annual NH3 concentrations and dry deposition. Largest impacts were predicted for woodland patches located within the agricultural area, while larger moorland areas were at low risk, due to atmospheric dispersion, prevailing wind direction and low NH3 background. These high resolution spatial details are lost in national scale estimates at 1 km resolution due to less detailed emission input maps. The results demonstrate how the spatial arrangement of sources and sinks is critical to defining the NH3 risk to semi-natural ecosystems. These spatial relationships provide the foundation for local spatial planning approaches to reduce environmental impacts of atmospheric NH3.

Flammability properties of dry sewage sludges

Dry sewage sludge are being considered as a possible energy source for direct firing. They have interesting properties to be used as an alternative fuel, but also other characteristics must be considered from the point of view of its safe operation: the most important are ignition sensitivity, explosion severity, thermal sensitivity and thermal stability. The aim of this study was to determine if sewage sludge have different characteristics due to different locations or seasons and how this influences their flammability properties. To study these characteristics sludge samples were selected from different locations in Spain, taken during different seasons. In addition, relationships between flammability parameters and chemical analysis were observed. Some parameters can be controlled during normal operation, such as granulometry or humidity, and may mean a decrease in the risk of explosion. Those relationships are well known for other dusts materials, like coal, but not yet for sewage sludge dusts. Finally, properties related to spontaneous combustion were determined (thermal susceptibility and stability). The addition of those properties to the study provides an overview of the thermal behavior of sewage sludge during their utilization, including transport and storage.

Dry sand as a specialized layer to improve the acoustic insulation between rooms one above another = La arena como capa intermedia especializada para la mejora del aislamiento acústico entre recintos superpuestos

Se comprueba la mejora en el aislamiento acústico entre recintos de la colocación de una capa de arean entre el solado y el forjado

Label-free biosensing for dry eye by Means of BICELLS

The use of Biophotonic Sensing Cells (BICELLs) based on micro-nano pattemed photonic architectures has been recently proven as an efficient methodology for label-free biosensing by using Optical Interrogation [1]. According to this, we have studied the different optical response for a specific typology of BICELL, consisting of structures of SU -8. This material is biocompatible with different types of biomolecules and can be immobilized on its sensing surface. In particular, we have measured the optical response for a biomarker in clinic diagnostic of dry eye. Although different proteins can be enstudied such as: PRDX5, ANXA 1, ANXA 11, CST 4, PLAA Y S 1 OOA6 related with ocular surface (dry eye), for this work PLAA (phospholipase A2) is studied by means of label free biosensing based on BICELLs for analyzing the performance and specificity according with means values of concentration in ROC curves.

Building resilience to water scarcity in Southern Spain: A case study of rice farming in Doñana protected wetlands

Agricultural water management needs to evolve in view of increased water scarcity, especially when farming and natural protected areas are closely linked. In the study site of Don?ana (southern Spain), water is shared by rice producers and a world heritage biodiversity ecosystem. Our aim is to contribute to defining adaptation strategies that may build resilience to increasing water scarcity and minimize water conflicts among agricultural and natural systems. The analytical framework links a participatory process with quantitative methods to prioritize the adaptation options. Bottom-up proposed adaptation measures are evaluated by a multi-criteria analysis (MCA) that includes both socioeconomic criteria and criteria of the ecosystem services affected by the adaptation options. Criteria weights are estimated by three different methods?analytic hierarchy process, Likert scale and equal weights?that are then compared. Finally, scores from an MCA are input into an optimization model used to determine the optimal land-use distribution in order to maximize utility and land-use diversification according to different scenarios of funds and water availability. While our results show a spectrum of perceptions of priorities among stakeholders, there is one overriding theme that is to define a way to restore part of the rice fields to natural wetlands. These results hold true under the current climate scenario and evenmore so under an increased water scarcity scenario.

Towards mitigation of greenhouse gases by small changes in farming practices: understanding local barriers in Spain.

Small changes in agricultural practices have a large potential for reducing greenhouse gas emissions. However, the implementation of such practices at the local level is often limited by a range of barriers. Understanding the barriers is essential for defining effective measures, the actual mitigation potential of the measures, and the policy needs to ensure implementation. Here we evaluate behavioural, cultural, and policy barriers for implementation of mitigation practices at the local level that imply small changes to farmers. The choice of potential mitigation practices relevant to the case study is based on a literature review of previous empirical studies. Two methods that include the stakeholders? involvement (experts and farmers) are undertaken for the prioritization of these potential practices: (a) Multi-criteria analysis (MCA) of the choices of an expert panel and (b) Analysis of barriers to implementation based on a survey of farmers. The MCA considers two future climate scenarios ? current climate and a drier and warmer climate scenario. Results suggest that all potential selected practices are suitable for mitigation considering multiple criteria in both scenarios. Nevertheless, if all the barriers for implementation had the same influence, the preferred mitigation practices in the case study would be changes in fertilization management and use of cover crops. The identification of barriers for the implementation of the practices is based on the econometric analysis of surveys given to farmers. Results show that farmers? environmental concerns, financial incentives and access to technical advice are the main factors that define their barriers to implementation. These results may contribute to develop effective mitigation policy to be included in the 2020 review of the European Union Common Agricultural Policy.

New agri-environmental policies for the sustainability of mountainous olive farming. Evidences from Andalusia, Spain

La sostenibilidad de los sistemas olivareros situados en zonas de pendiente y montaña (SMOPS) en Andalucía se encuentra actualmente amenazada por las elevadas tasas de abandono que afectan a estos sistemas productivos. Así, la consumación de este proceso de abandono, no sólo pondría en peligro a las propias explotaciones, sino a todo el conjunto de bienes y servicios no productivos y al patrimonio cultural generado por este sistema productivo. En este contexto, la búsqueda de alternativas políticas enfocadas a revertir este proceso se erige como una necesidad categórica en aras de garantizar en el largo plazo la sostenibilidad de los olivares de montaña. Esta tesis pretende hacer frente a esta necesidad a través de la construcción de un marco político alternativo para los SMOPS, que permita la integración simultánea de todas las dimensiones que pueden influir en su desarrollo; esto es: el marco político actual, principalmente determinado por la Política Agraria Común (PAC) de la Unión Europea (UE); las preferencias de la sociedad hacia la oferta de bienes y servicios públicos generados por los SMOPS; y las preferencias y voluntad de innovación hacia nuevos manejos y sistemas de gestión de los agricultores y propietarios de las explotaciones. Para ello, se emplea una metodología de investigación mixta, que abarca la realización de cuatro encuestas (personales y online) llevadas a cabo a los agentes o grupos de interés involucrados directa o indirectamente en la gestión de los SMOPS –ciudadanos, agricultores y propietarios y expertos-; una profunda revisión de las herramientas de política agroambiental actuales y posibles alternativas a las mismas; y el desarrollo de nuevas estrategias metodológicas para dotar de mayor precisión y fiabilidad las estimaciones obtenidas a partir del Método del Experimento de Elección (MEE) en el campo de la valoración medioambiental. En general, los resultados muestran que una estrategia de política agroambiental basada en la combinación de los Contratos Territoriales de Zona Rural (CTZR) y el manejo ecológico supondría una mejora en la sostenibilidad de los sistemas olivareros de montaña andaluces, que, al mismo tiempo, propiciaría una mejor consideración de las necesidades y demandas de los agentes implicados en su gestión. Asimismo, los hallazgos obtenidos en esta investigación demandan un cambio de paradigma en los actuales pagos agroambientales, que han de pasar de una estrategia basada en la implementación de acciones, a otra enfocada al logro de objetivos, la cual, en el caso del olivar, se podría centrar en el aumento del secuestro de carbono en el suelo. Desde un punto de vista metodológico, los resultados han contribuido notablemente a mejorar la fiabilidad y precisión de las conclusiones estimadas a partir del MEE, mediante el diseño de un novedoso proceso iterativo para detectar posibles comportamientos inconsistentes por parte de los entrevistados con respecto a su máxima Disposición al Pago (DAP) para lograr la situación considerada como “óptima” en los olivares ecológicos de montaña andaluces. En líneas generales, el actual marco institucional favorece la puesta en práctica de la mayoría de las estrategias propuestas en esta tesis; sin embargo son necesarios mayores esfuerzos para reconducir los actuales Pagos Agroambientales y Climáticos de la PAC, hacia una estrategia de política agroambiental adaptada a las necesidades y requisitos del territorio en el que se aplica, enfocada al logro de objetivos y que sea capaz de integrar y coordinar al conjunto de agentes y grupos de interés involucrados -directa o indirectamente- en la gestión de los olivares de montaña. En este contexto, se espera que la puesta en práctica de nuevas estructuras y acuerdos de gobernanza territorial juegue un importante papel en el desarrollo de una política agroambiental realmente adaptada a las necesidades de los sistemas olivareros de montaña andaluces. ABSTRACT The long-term sustainability of Andalusian sloping and mountainous olive production systems (SMOPS) is currently threatened by the high abandonment rates that affect these production systems. The effective occurrence of this abandonment process is indeed menacing not only farms themselves, but also the wide array of public goods and services provided by SMOPS and the cultural heritage held by this production system. The search of policy alternatives aimed at tackling this process is thus a central necessity. This thesis aims to undertake this necessity by building an alternative policy framework for SMOPS that simultaneously integrates the several dimensions that are susceptible to influence it, namely: the current policy framework, mainly determined by the European Union’s (EU) Common Agricultural Policy (CAP); the social preferences toward the supply of SMOPS’ public goods and services; and farmers’ preferences and willingness to innovate toward new management practices in their farms. For this purpose, we put into practice a mixed-method strategy that combines four face-to-face and online surveys carried out with SMOPS’ stakeholders -including citizens, farmers and experts-; in-depth analysis of current and alternative agrienvironmental policy (AEP) instruments; and the development of novel methodological approaches to advance toward more reliable Discrete Choice Experiment’s (DCE) outcomes in the field of environmental valuation. Overall, results show that a policy strategy based on the combination of Territorial Management Contracts (TMC) and organic management would further enhance Andalusian SMOPS’ sustainability by simultaneously taking into account stakeholders’ demands and needs. Findings also call for paradigm shift of the current action-oriented design of Agri-Environmental-Climate Schemes (AECS), toward a result-based approach, that in the case of olive orchards should particularly be focused on enhancing soil carbon sequestration. From a methodological perspective, results have contributed to improve the accuracy and feasibility of DCE outcomes by designing a novel and iterative procedure focused in ascertaining respondents’ inconsistent behaviour with respect to their stated maximum WTP for the attainment of an ideal situation to be achieved in organic Andalusian SMOPS. Generally, the present institutional framework favours the implementation of the main policy strategies proposed in this thesis, albeit further efforts are required to better conduct current CAP’s agri-environmental instruments toward a territorially targeted result-oriented strategy capable to integrate and coordinate the whole set of stakeholders involved in the management of SMOPS. In this regard, alternative governance structures and arrangements are expected to play a major role on the process of tackling SMOPS’ agri-environmental policy challenge.