Global research alliance modelling platform (GRAMP): an open web platform for modelling greenhouse gas emissions from agro-ecosystems

Carbon (C) and nitrogen (N) process-based models are important tools for estimating and reporting greenhouse gas emissions and changes in soil C stocks. There is a need for continuous evaluation, development and adaptation of these models to improve scientific understanding, national inventories and assessment of mitigation options across the world. To date, much of the information needed to describe different processes like transpiration, photosynthesis, plant growth and maintenance, above and below ground carbon dynamics, decomposition and nitrogen mineralization. In ecosystem models remains inaccessible to the wider community, being stored within model computer source code, or held internally by modelling teams. Here we describe the Global Research Alliance Modelling Platform (GRAMP), a web-based modelling platform to link researchers with appropriate datasets, models and training material. It will provide access to model source code and an interactive platform for researchers to form a consensus on existing methods, and to synthesize new ideas, which will help to advance progress in this area. The platform will eventually support a variety of models, but to trial the platform and test the architecture and functionality, it was piloted with variants of the DNDC model. The intention is to form a worldwide collaborative network (a virtual laboratory) via an interactive website with access to models and best practice guidelines; appropriate datasets for testing, calibrating and evaluating models; on-line tutorials and links to modelling and data provider research groups, and their associated publications. A graphical user interface has been designed to view the model development tree and access all of the above functions.

Flujos de gases de efecto invernadero en suelos forestales y agroforestales del centro de la Península Ibérica=Greenhouse gas flows in forest and agroforestry soils in the center of the Iberian Peninsula

Debido a la complejidad de los procesos que controlan el intercambio de gases de carbono (C) y nitrógeno (N) entre el suelo y la atmósfera, en los sistemas forestales y agroforestales, son comprensibles las incógnitas existentes respecto a la estimación de los flujos de los gases de efecto invernadero (GEI) y la capacidad como reservorios de carbono de los suelos, bajo diferentes formas de uso y regímenes de alteración a escala regional y global. Esta escasez de información justifica la necesidad de caracterizar la dinámica de intercambio de GEI en los ecosistemas Mediterráneos, en especial en el contexto actual de cambio climático, y el incremento asociado de temperatura y periodos de sequía, alteración de los patrones de precipitación, y el riesgo de incendios forestales; cuyas consecuencias afectarán tanto a los compartimentos de C y de N del suelo como a la capacidad de secuestro de C de estos ecosistemas. Dentro de este contexto se enmarca la presente tesis doctoral cuyo objetivo ha sido cuantificar y caracterizar los flujos de dióxido de carbono (CO2), de oxido nitroso (N2O) y de metano (CH4), junto con los stocks de C y N, en suelos forestales de Quercus ilex, Quercus pyrenaica y Pinus sylvestris afectados por incendios forestales; así como el estudiar el efecto de la gestión y la cubierta arbórea en la respiración del suelo y los stocks de C y N en una dehesa situada en el centro de la Península Ibérica. De manera que los flujos de CO2, N2O y CH4; y los parámetros físico-químicos y biológicos del suelo fueron estudiados en los diferentes tratamientos y ecosistemas a lo largo del trabajo que se presenta. Los resultados obtenidos muestran la existencia de variaciones temporales y espaciales de la respiración del suelo dentro de una escala geográfica pequeña, controladas principalmente por la temperatura y la humedad del suelo; y por los contenidos de C y N del suelo en un bosque de Pinus sylvestris en la vertiente norte de la Sierra de Guadarrama , en España. El análisis de los efectos de los incendios forestales a largo plazo (6-8 años) revela que las pérdidas anuales de C a través de la respiración del suelo en las zonas quemadas de Quercus ilex, Quercus pyrenaica y Pinus sylvestris fueron 450 gCm-2yr-1, 790 gCm-2yr-1 y 1220 gCm-2yr-1, respectivamente; lo que representa una reducción del 43%, 22% y 11% en comparación con las zonas no quemadas de dichas especies, debido a la destrucción de la masa arbórea. El efecto del fuego también alteró los flujos N2O y CH4 del suelo, de una forma diferente en los distintos ecosistemas y estacionalidades estudiadas. De tal modo, que los suelos quemados mostraron una mayor oxidación del CH4 en las masas de Q. ilex, y una menor oxidación en las de P. sylvestris; además de una disminución de los flujos de N2O en Q. pyrenaica. Los incendios también afectaron los parámetros microclimáticos de los suelos forestales, observándose un incremento de la temperatura del suelo y una disminución de la humedad en los emplazamientos quemados que en los no quemados. Los cationes intercambiables, el pH, el cociente C/N, el contenido en raicillas y la biomasa microbiana también disminuyeron en las zonas quemadas. Aunque el C orgánico del suelo no se alteró de manera significativa, si lo hizo la calidad de la materia orgánica, disminuyendo el carbono lábil y aumentando las formas recalcitrantes lo que se tradujo en menor sensibilidad de la respiración del suelo a la temperatura (valores de Q10) en las zonas quemadas. Los resultados del estudio realizado en la Dehesa muestran que las actividades silvopastorales estudiadas afectaron levemente y de forma no constante a la respiración del suelo y las condiciones microclimáticas del suelo. Se observó una reducción 12% de la respiración del suelo por efecto del pastoreo no intensivo. Sin embargo, se observaron incrementos de 3Mg/ha en los stocks de C y de 0.3 Mg/ha en los stocks de N en los suelos pastoreados en comparación con los no pastoreados. Aunque, no se observó un claro efecto de la labranza sobre la respiración del suelo en nuestro experimento, sin embargo si se observó una disminución de 3.5 Mg/ha en las reservas de C y de 0.3 Mg/ ha en las de N en los suelos labrados comparados con los no labrados. La copa del arbolado influyó de forma positiva tanto en la respiración del suelo, como en los stocks de C y N de los suelos. La humedad del suelo jugó un papel relevante en la sensibilidad de la respiración a la temperatura del suelo. Nuestros resultados ponen de manifiesto la sensibilidad de la respiración del suelo a cambios en la humedad y los parámetros edáficos, y sugieren que la aplicación de modelos estándar para estimar la respiración del suelo en áreas geográficas pequeñas puede no ser adecuada a menos que otros factores sean considerados en combinación con la temperatura del suelo. Además, las diferentes respuestas de los flujos de gases de efecto invernadero a los cambios, años después de la ocurrencia de incendios forestales, destaca la necesidad de incluir estos cambios en las futuras investigaciones de la dinámica del carbono en los ecosistemas mediterráneos. Por otra parte, las respuestas divergentes en los valores de respiración del suelo y en los contenidos de C y N del suelo observados en la dehesa, además de la contribución de la copa de los árboles en los nutrientes del suelo ilustran la importancia de mantener la gestión tradicional aplicada en beneficio de la capacidad de almacenar C en la dehesa estudiada. La información obtenida en este trabajo pretende contribuir a la mejora del conocimiento de la dinámica y el balance de C en los sistemas mediterráneos, además de ayudar a predecir el impacto del cambio climático en el intercambio de C entre los ecosistemas forestales y agroforestales y la atmósfera. ABSTRACT Due to the complexity of the processes that control the exchange of carbon (C) and nitrogen (N) gasses between soils and the atmosphere in forest and agroforestry ecosystems, understandable uncertainties exist as regards the estimation of greenhouse gas (GHG) fluxes and the soil sink capacity at regional and global scale under different forms of land use and disturbance regimes. These uncertainties justify the need to characterize the exchange dynamics of GHG between the atmosphere and soils in Mediterranean terrestrial ecosystems, particularly in the current context of climate change and the associated increase in temperature, drought periods, heavy rainfall events, and increased risk of wildfires, which affect not only the C and N pools but also the soil C sink capacity of these ecosystems. Within this context, the aims of the present thesis were, firstly, to quantify and characterize the fluxes of carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) as well as the C and N stocks in Quercus ilex, Quercus pyrenaica and Pinus sylvestris stands affected by wildfires, and secondly, to study the effects of Quercus ilex canopy and management on both soil respiration and C and N pools in dehesa systems in the center of Iberian Peninsula. Soil CO2, N2O and CH4 fluxes, and soil physical-chemical and biological parameters were studied under the different treatments and ecosystems considered in this study. The results showed seasonal and spatial variations in soil respiration within small geographic areas, mainly controlled by soil temperature and moisture in addition to soil carbon and nitrogen stocks in mixed pine–oak forest ecosystems on the north facing slopes of the Sierra de Guadarrama in Spain. The analysis of long term effects of wildfires (6–8 years) revealed that annual carbon losses through soil respiration from burned sites in Quercus ilex, Quercus pyrenaica and Pinus sylvestris stands were 450 gCm-2yr-1, 790 gCm-2yr-1 and 1220 gCm-2yr-1, respectively; with burned sites emitting 43%, 22% and 11% less in burned as opposed to non-burned sites due the loss of trees. Fire may alter both N2O and CH4 fluxes although the magnitude of such variation depends on the site, soil characteristics and seasonal climatic conditions. The burned sites showed higher CH4 oxidation in Q.ilex stands, and lower oxidation rates in P. sylvestris stands. A reduction in N2O fluxes in Q. pyrenaica stands was detected at burned sites along with changes in soil microclimate; higher soil temperature and lower soil moisture content. Exchangeable cations, the C/N ratio, pH, fine root and microbial biomass were also found to decrease at burned sites. Although the soil organic carbon was not significantly altered, the quality of the organic matter changed, displaying a decrease in labile carbon and a relative increase in refractory forms, leading to lower sensitivity of soil respiration to temperature (Q10 values) at burned sites. The results from the dehesa study show that light grazing and superficial tilling practices used in the studied dehesa system in Spain had a slight but non-consistent impact on soil respiration and soil microclimate over the study period. The reduction in soil respiration in the dehesa system due to the effects of grazing was around 12 %. However, increments of 3Mg/ha in C stocks and 0.3 Mg/ha in N stocks in grazed soils were observed. Although no clear effect of tilling on soil respiration was found, a decrease of 3.5 Mg/ha in C stocks and 0.3 Mg/ha in N stocks was detected for tilled soils. The presence of a tree canopy induced increases in soil respiration, soil C and N stocks, while soil moisture was found to play an important role in soil respiration temperature response. Our results suggest that the use of standard models to estimate soil respiration in small geographical areas may not be adequate unless other factors are considered in addition to soil temperature. Furthermore, the different responses of GHG flux to climatic shifts, many years after the occurrence of wildfire, highlight the need to include these shifts in C dynamics in future research undertaken in Mediterranean ecosystems. Furthermore, divergent responses in soil respiration and soil C and N stocks to grazing or tilling practices in Dehesa systems, and the influence of tree canopy on soil respiration and soil nutrient content, illustrate the importance of maintaining beneficial management practices. Moreover, the carbon sequestration capacity of the Dehesa system studied may be enhanced through improvements in the management applied. It is hoped that the information obtained through this research will contribute towards improving our understanding of the dynamics and balance of C in Mediterranean systems, and help predict the impact of climate change on the exchange of C between forest and agroforestry ecosystems and the atmosphere.

Dietary Fibre in Pig's Diets: Effects on Greenhouse Gas Emissions from Slurry Storage to Field Application

Pig’s slurry is a key source of greenhouse gases (GHG). In Spain, GHG emissions (CH4+ N2O) from pig slurry (storage and land application) accounted in 2011 for 18.4% of total GHG emissions (in CO2- equivalent) of the agriculture sector according to the National Inventory Report (NIR). Slurry composition can be modified through diet manipulation. The aim of this work was to evaluate the effect of different fibre types in fattening pigs’ diets on GHG emissions from pig slurry storage and field application.

Nitrous oxide emissions from European agriculture - an analysis of variability and drivers of emissions from field experiments

Nitrous oxide emissions from a network of agricultural experiments in Europe were used to explore the relative importance of site and management controls of emissions. At each site, a selection of management interventions were compared within replicated experimental designs in plot-based experiments. Arable experiments were conducted at Beano in Italy, El Encin in Spain, Foulum in Denmark, Logarden in Sweden, Maulde in Belgium CE1, Paulinenaue in Germany, and Tulloch in the UK. Grassland experiments were conducted at Crichton, Nafferton and Peaknaze in the UK, Godollo in Hungary, Rzecin in Poland, Zarnekow in Germany and Theix in France. Nitrous oxide emissions were measured at each site over a period of at least two years using static chambers. Emissions varied widely between sites and as a result of manipulation treatments. Average site emissions (throughout the study period) varied between 0.04 and 21.21 kg N2O-N ha−1yr−1, with the largest fluxes and variability associated with the grassland sites. Total nitrogen addition was found to be the single most important deter- minant of emissions, accounting for 15 % of the variance (using linear regression) in the data from the arable sites (p<0.0001), and 77 % in the grassland sites. The annual emissions from arable sites were significantly greater than those that would be predicted by IPCC default emission fac- tors. Variability of N2O emissions within sites that occurred as a result of manipulation treatments was greater than that resulting from site-to-site and year-to-year variation, highlighting the importance of management interventions in contributing to greenhouse gas mitigation

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.

Exploring strategic farming choices to respond to mitigation and adaptation to climate change

Las alteraciones del sistema climático debido al aumento de concentraciones de gases de efecto invernadero (GEI) en la atmósfera, tendrán implicaciones importantes para la agricultura, el medio ambiente y la sociedad. La agricultura es una fuente importante de emisiones de gases de efecto invernadero (globalmente contribuye al 12% del total de GEI), y al mismo tiempo puede ser parte de la solución para mitigar las emisiones y adaptarse al cambio climático. Las acciones frente al desafío del cambio climático deben priorizar estrategias de adaptación y mitigación en la agricultura dentro de la agenda para el desarrollo de políticas. La agricultura es por tanto crucial para la conservación y el uso sostenible de los recursos naturales, que ya están sometidos a impactos del cambio climático, al mismo tiempo que debe suministrar alimentos para una población creciente. Por tanto, es necesaria una coordinación entre las actuales estrategias de política climática y agrícola. El concepto de agricultura climáticamente inteligente ha surgido para integrar todos estos servicios de la producción agraria. Al evaluar opciones para reducir las amenazas del cambio climático para la agricultura y el medio ambiente, surgen dos preguntas de investigación: • ¿Qué información es necesaria para definir prácticas agrarias inteligentes? • ¿Qué factores influyen en la implementación de las prácticas agrarias inteligentes? Esta Tesis trata de proporcionar información relevante sobre estas cuestiones generales con el fin de apoyar el desarrollo de la política climática. Se centra en sistemas agrícolas Mediterráneos. Esta Tesis integra diferentes métodos y herramientas para evaluar las alternativas de gestión agrícola y políticas con potencial para responder a las necesidades de mitigación y adaptación al cambio climático. La investigación incluye enfoques cuantitativos y cualitativos e integra variables agronómicas, de clima y socioeconómicas a escala local y regional. La investigación aporta una recopilación de datos sobre evidencia experimental existente, y un estudio integrado sobre el comportamiento de los agricultores y las posibles alternativas de cambio (por ejemplo, la tecnología, la gestión agrícola y la política climática). Los casos de estudio de esta Tesis - el humedal de Doñana (S España) y la región de Aragón (NE España) - permiten ilustrar dos sistemas Mediterráneos representativos, donde el uso intensivo de la agricultura y las condiciones semiáridas son ya una preocupación. Por este motivo, la adopción de estrategias de mitigación y adaptación puede desempeñar un papel muy importante a la hora de encontrar un equilibrio entre la equidad, la seguridad económica y el medio ambiente en los escenarios de cambio climático. La metodología multidisciplinar de esta tesis incluye una amplia gama de enfoques y métodos para la recopilación y el análisis de datos. La toma de datos se apoya en la revisión bibliográfica de evidencia experimental, bases de datos públicas nacionales e internacionales y datos primarios recopilados mediante entrevistas semi-estructuradas con los grupos de interés (administraciones públicas, responsables políticos, asesores agrícolas, científicos y agricultores) y encuestas con agricultores. Los métodos de análisis incluyen: meta-análisis, modelos de gestión de recursos hídricos (modelo WAAPA), análisis multicriterio para la toma de decisiones, métodos estadísticos (modelos de regresión logística y de Poisson) y herramientas para el desarrollo de políticas basadas en la ciencia. El meta-análisis identifica los umbrales críticos de temperatura que repercuten en el crecimiento y el desarrollo de los tres cultivos principales para la seguridad alimentaria (arroz, maíz y trigo). El modelo WAAPA evalúa el efecto del cambio climático en la gestión del agua para la agricultura de acuerdo a diferentes alternativas políticas y escenarios climáticos. El análisis multicriterio evalúa la viabilidad de las prácticas agrícolas de mitigación en dos escenarios climáticos de acuerdo a la percepción de diferentes expertos. Los métodos estadísticos analizan los determinantes y las barreras para la adopción de prácticas agrícolas de mitigación. Las herramientas para el desarrollo de políticas basadas en la ciencia muestran el potencial y el coste para reducir GEI mediante las prácticas agrícolas. En general, los resultados de esta Tesis proporcionan información sobre la adaptación y la mitigación del cambio climático a nivel de explotación para desarrollar una política climática más integrada y ayudar a los agricultores en la toma de decisiones. Los resultados muestran las temperaturas umbral y la respuesta del arroz, el maíz y el trigo a temperaturas extremas, siendo estos valores de gran utilidad para futuros estudios de impacto y adaptación. Los resultados obtenidos también aportan una serie de estrategias flexibles para la adaptación y la mitigación a escala local, proporcionando a su vez una mejor comprensión sobre las barreras y los incentivos para su adopción. La capacidad de mejorar la disponibilidad de agua y el potencial y el coste de reducción de GEI se han estimado para estas estrategias en los casos de estudio. Estos resultados podrían ayudar en el desarrollo de planes locales de adaptación y políticas regionales de mitigación, especialmente en las regiones Mediterráneas. ABSTRACT Alterations in the climatic system due to increased atmospheric concentrations of greenhouse gas emissions (GHG) are expected to have important implications for agriculture, the environment and society. Agriculture is an important source of GHG emissions (12 % of global anthropogenic GHG), but it is also part of the solution to mitigate emissions and to adapt to climate change. Responses to face the challenge of climate change should place agricultural adaptation and mitigation strategies at the heart of the climate change agenda. Agriculture is crucial for the conservation and sustainable use of natural resources, which already stand under pressure due to climate change impacts, increased population, pollution and fragmented and uncoordinated climate policy strategies. The concept of climate smart agriculture has emerged to encompass all these issues as a whole. When assessing choices aimed at reducing threats to agriculture and the environment under climate change, two research questions arise: • What information defines smart farming choices? • What drives the implementation of smart farming choices? This Thesis aims to provide information on these broad questions in order to support climate policy development focusing in some Mediterranean agricultural systems. This Thesis integrates methods and tools to evaluate potential farming and policy choices to respond to mitigation and adaptation to climate change. The assessment involves both quantitative and qualitative approaches and integrates agronomic, climate and socioeconomic variables at local and regional scale. The assessment includes the collection of data on previous experimental evidence, and the integration of farmer behaviour and policy choices (e.g., technology, agricultural management and climate policy). The case study areas -- the Doñana coastal wetland (S Spain) and the Aragón region (NE Spain) – illustrate two representative Mediterranean regions where the intensive use of agriculture and the semi-arid conditions are already a concern. Thus the adoption of mitigation and adaptation measures can play a significant role for reaching a balance among equity, economic security and the environment under climate change scenarios. The multidisciplinary methodology of this Thesis includes a wide range of approaches for collecting and analysing data. The data collection process include revision of existing experimental evidence, public databases and the contribution of primary data gathering by semi-structured interviews with relevant stakeholders (i.e., public administrations, policy makers, agricultural advisors, scientist and farmers among others) and surveys given to farmers. The analytical methods include meta-analysis, water availability models (WAAPA model), decision making analysis (MCA, multi-criteria analysis), statistical approaches (Logistic and Poisson regression models) and science-base policy tools (MACC, marginal abatement cost curves and SOC abatement wedges). The meta-analysis identifies the critical temperature thresholds which impact on the growth and development of three major crops (i.e., rice, maize and wheat). The WAAPA model assesses the effect of climate change for agricultural water management under different policy choices and climate scenarios. The multi-criteria analysis evaluates the feasibility of mitigation farming practices under two climate scenarios according to the expert views. The statistical approaches analyses the drivers and the barriers for the adoption of mitigation farming practices. The science-base policy tools illustrate the mitigation potential and cost effectiveness of the farming practices. Overall, the results of this Thesis provide information to adapt to, and mitigate of, climate change at farm level to support the development of a comprehensive climate policy and to assist farmers. The findings show the key temperature thresholds and response to extreme temperature effects for rice, maize and wheat, so such responses can be included into crop impact and adaptation models. A portfolio of flexible adaptation and mitigation choices at local scale are identified. The results also provide a better understanding of the stakeholders oppose or support to adopt the choices which could be used to incorporate in local adaptation plans and mitigation regional policy. The findings include estimations for the farming and policy choices on the capacity to improve water supply reliability, abatement potential and cost-effective in Mediterranean regions.

Climate change technology transfer to developing countries: evidence analysis and policy recommendations

Developing countries are experiencing unprecedented levels of economic growth. As a result, they will be responsible for most of the future growth in energy demand and greenhouse gas (GHG) emissions. Curbing GHG emissions in developing countries has become one of the cornerstones of a future international agreement under the United Nations Framework Convention for Climate Change (UNFCCC). However, setting caps for developing countries’ GHG emissions has encountered strong resistance in the current round of negotiations. Continued economic growth that allows poverty eradication is still the main priority for most developing countries, and caps are perceived as a constraint to future growth prospects. The development, transfer and use of low-carbon technologies have more positive connotations, and are seen as the potential path towards low-carbon development. So far, the success of the UNFCCC process in improving the levels of technology transfer (TT) to developing countries has been limited. This thesis analyses the causes for such limited success and seeks to improve on the understanding about what constitutes TT in the field of climate change, establish the factors that enable them in developing countries and determine which policies could be implemented to reinforce these factors. Despite the wide recognition of the importance of technology and knowledge transfer to developing countries in the climate change mitigation policy agenda, this issue has not received sufficient attention in academic research. Current definitions of climate change TT barely take into account the perspective of actors involved in actual climate change TT activities, while respective measurements do not bear in mind the diversity of channels through which these happen and the outputs and effects that they convey. Furthermore, the enabling factors for TT in non-BRIC (Brazil, Russia, India, China) developing countries have been seldom investigated, and policy recommendations to improve the level and quality of TTs to developing countries have not been adapted to the specific needs of highly heterogeneous countries, commonly denominated as “developing countries”. This thesis contributes to enriching the climate change TT debate from the perspective of a smaller emerging economy (Chile) and by undertaking a quantitative analysis of enabling factors for TT in a large sample of developing countries. Two methodological approaches are used to study climate change TT: comparative case study analysis and quantitative analysis. Comparative case studies analyse TT processes in ten cases based in Chile, all of which share the same economic, technological and policy frameworks, thus enabling us to draw conclusions on the enabling factors and obstacles operating in TT processes. The quantitative analysis uses three methodologies – principal component analysis, multiple regression analysis and cluster analysis – to assess the performance of developing countries in a number of enabling factors and the relationship between these factors and indicators of TT, as well as to create groups of developing countries with similar performances. The findings of this thesis are structured to provide responses to four main research questions: What constitutes technology transfer and how does it happen? Is it possible to measure technology transfer, and what are the main challenges in doing so? Which factors enable climate change technology transfer to developing countries? And how do different developing countries perform in these enabling factors, and how can differentiated policy priorities be defined accordingly? vi Resumen Los paises en desarrollo estan experimentando niveles de crecimiento economico sin precedentes. Como consecuencia, se espera que sean responsables de la mayor parte del futuro crecimiento global en demanda energetica y emisiones de Gases de Efecto de Invernadero (GEI). Reducir las emisiones de GEI en los paises en desarrollo es por tanto uno de los pilares de un futuro acuerdo internacional en el marco de la Convencion Marco de las Naciones Unidas para el Cambio Climatico (UNFCCC). La posibilidad de compromisos vinculantes de reduccion de emisiones de GEI ha sido rechazada por los paises en desarrollo, que perciben estos limites como frenos a su desarrollo economico y a su prioridad principal de erradicacion de la pobreza. El desarrollo, transferencia y uso de tecnologias bajas en carbono tiene connotaciones mas positivas y se percibe como la via hacia un crecimiento bajo en carbono. Hasta el momento, la UNFCCC ha tenido un exito limitado en la promocion de transferencias de tecnologia (TT) a paises en desarrollo. Esta tesis analiza las causas de este resultado y busca mejorar la comprension sobre que constituye transferencia de tecnologia en el area de cambio climatico, cuales son los factores que la facilitan en paises en desarrollo y que politicas podrian implementarse para reforzar dichos factores. A pesar del extendido reconocimiento sobre la importancia de la transferencia de tecnologia a paises en desarrollo en la agenda politica de cambio climatico, esta cuestion no ha sido suficientemente atendida por la investigacion existente. Las definiciones actuales de transferencia de tecnologia relacionada con la mitigacion del cambio climatico no tienen en cuenta la diversidad de canales por las que se manifiestan o los efectos que consiguen. Los factores facilitadores de TT en paises en desarrollo no BRIC (Brasil, Rusia, India y China) apenas han sido investigados, y las recomendaciones politicas para aumentar el nivel y la calidad de la TT no se han adaptado a las necesidades especificas de paises muy heterogeneos aglutinados bajo el denominado grupo de "paises en desarrollo". Esta tesis contribuye a enriquecer el debate sobre la TT de cambio climatico con la perspectiva de una economia emergente de pequeno tamano (Chile) y el analisis cuantitativo de factores que facilitan la TT en una amplia muestra de paises en desarrollo. Se utilizan dos metodologias para el estudio de la TT a paises en desarrollo: analisis comparativo de casos de estudio y analisis cuantitativo basado en metodos multivariantes. Los casos de estudio analizan procesos de TT en diez casos basados en Chile, para derivar conclusiones sobre los factores que facilitan u obstaculizan el proceso de transferencia. El analisis cuantitativo multivariante utiliza tres metodologias: regresion multiple, analisis de componentes principales y analisis cluster. Con dichas metodologias se busca analizar el posicionamiento de diversos paises en cuanto a factores que facilitan la TT; las relaciones entre dichos factores e indicadores de transferencia tecnologica; y crear grupos de paises con caracteristicas similares que podrian beneficiarse de politicas similares para la promocion de la transferencia de tecnologia. Los resultados de la tesis se estructuran en torno a cuatro preguntas de investigacion: .Que es la transferencia de tecnologia y como ocurre?; .Es posible medir la transferencia de tecnologias de bajo carbono?; .Que factores facilitan la transferencia de tecnologias de bajo carbono a paises en desarrollo? y .Como se puede agrupar a los paises en desarrollo en funcion de sus necesidades politicas para la promocion de la transferencia de tecnologias de bajo carbono?

Diffuse Soil Co2 Flux To Assess The Reliability Of Co2 Storage In The Mazarrón-Gañuelas Tertiary Basin (Spain)

Geological storage of CO2 is nowadays internationally considered as the most effective method for greenhouse gas emission mitigation, in order to minimize its effects on the global climatology. One of the main options is to store the CO2 in deep saline aquifers at more than 800 m depth, because it achieves its supercritical state. Among the most important aspects concerning the performance assessment of a deep CO2 geological repository is the evaluation of the CO2 leakage rate from the chosen storage geological formation. Therefore, it is absolutely necessary to increase the knowledge on the interaction among CO2, storage and sealing formations, as well as on the flow paths for CO2 and the physico-mechanical resistance of the sealing formation. Furthermore, the quantification of the CO2 leakage rate is essential to evaluate its effects on the environment. One way to achieve this objective is to study of CO2 leakage on natural analogue systems, because they can provide useful information about the natural performance of the CO2, which can be applied to an artificial CO2 geological storage. This work is focused on the retention capacity of the cap-rock by measuring the diffuse soil CO2 flux in a site selected based on: i) the presence of a natural and deep CO2 accumulation; ii) its structural geological characteristics; and iii) the nature of the cap-rocks. This site is located in the so-called Mazarrón-Gañuelas Tertiary Basin, in the Guadalentin Valley, province of Murcia (Spain) Therefore the main objective of this investigation has been to detect the possible leakages of CO2 from a deep saline aquifer to the surface in order to understand the capability of this area as a natural analogue for Carbon Capture and Sequestration (CCS). The results obtained allow to conclude that the geological sealing formation of the basin seems to be appropriate to avoid CO2 leakages from the storage formation.

Effects on the shallow aquifers by CO2 leakages in a tertiary basin (province of Murcia, Spain)

Geological storage of CO2 is nowadays internationally considered as the most effective method for greenhouse gas emission mitigation, in order to minimize its effects on the global climatology. One of the main options is to store CO2 in deep saline aquifers at more than 800m depth, because it reaches its supercritical state. Study of the CO2 natural accumulations as natural analogues of an artificial CO2 storage is very useful in order to understand the CO2 long term behaviour and thus to predict its possible impact on the surficial environment and life. Therefore the main objective of this work is to detect the affection of the CO2 leakages from a deep saline aquifer on the shallow aquifers, all of them located in the Gañuelas-Mazarrón Tertiary basin (Province of Murcia, Spain). This CO2 storage and leakage natural system can be analogous to an artificial CO2 storage with leakage phenomena. In order to reach these objectives, groundwaters from different aquifers in the site have been sampled and analysed for major elements, free and dissolved gases and stable isotopes, particularly ∂ 13 C and 3 He/ 4 He. The results obtained allow to conclude that this natural system is an interesting example of natural analogue for an artificial CO2 storage affected by leakage processes because the shallow fresh aquifers in the site are polluted by CO2 from the deep saline aquifer as a consequence of an intensive over-exploitation of these freshwater aquifers

Farm nitrogen balances in six European landscapes as an indicator for nitrogen losses and basis for improved management.

Improved management of nitrogen (N) in agriculture is necessary to achieve a sustainable balance between the production of food and other biomass, and the unwanted effects of N on water pollution, greenhouse gas emissions, biodiversity deterioration and human health. To analyse farm N-losses and the complex interactions within farming systems, efficient methods for identifying emissions hotspots and evaluating mitigation measures are therefore needed. The present paper aims to fill this gap at the farm and landscape scales. Six agricultural landscapes in Poland (PL), the Netherlands (NL), France (FR), Italy (IT), Scotland (UK) and Denmark (DK) were studied, and a common method was developed for undertaking farm inventories and the derivation of farm N balances, N surpluses and for evaluating uncertainty for the 222 farms and 11 440 ha of farmland included in the study. In all landscapes, a large variation in the farm N surplus was found, and thereby a large potential for reductions. The highest average N surpluses were found in the most livestock-intensive landscapes of IT, FR, and NL; on average 202 ± 28, 179 ± 63 and 178 ± 20 kg N ha−1 yr−1, respectively. All landscapes showed hotspots, especially from livestock farms, including a special UK case with large-scale landless poultry farming. Overall, the average N surplus from the land-based UK farms dominated by extensive sheep and cattle grazing was only 31 ± 10 kg N ha−1 yr−1, but was similar to the N surplus of PL and DK (122 ± 20 and 146 ± 55 kg N ha−1 yr−1, respectively) when landless poultry farming was included. We found farm N balances to be a useful indicator for N losses and the potential for improving N management. Significant correlations to N surplus were found, both with ammonia air concentrations and nitrate concentrations in soils and groundwater, measured during the period of N management data collection in the landscapes from 2007–2009. This indicates that farm N surpluses may be used as an independent dataset for validation of measured and modelled N emissions in agricultural landscapes. No significant correlation was found with N measured in surface waters, probably because of spatial and temporal variations in groundwater buffering and biogeochemical reactions affecting N flows from farm to surface waters. A case study of the development in N surplus from the landscape in DK from 1998–2008 showed a 22% reduction related to measures targeted at N emissions from livestock farms. Based on the large differences in N surplus between average N management farms and the most modern and N-efficient farms, it was concluded that additional N-surplus reductions of 25–50%, as compared to the present level, were realistic in all landscapes. The implemented N-surplus method was thus effective for comparing and synthesizing results on farm N emissions and the potentials of mitigation options. It is recommended for use in combination with other methods for the assessment of landscape N emissions and farm N efficiency, including more detailed N source and N sink hotspot mapping, measurements and modelling.

Gasification technology assessment of sterile coal to clean electrical power generation.

Sterile coal is a low-value residue associated to the coal extraction and mining activity. According to the type and origin of the coal bed configuration, sterile coal production can mainly vary on quantity, calorific value and presence of sulphur compounds. In addition, the potential availability of sterile coal within Spain is apparently high and its contribution to the local power generation would be of interest playing a significant role. The proposed study evaluates the availability and deployment of gasification technologies to drive clean electricity generation from waste coal and sterile rock coal, incorporating greenhouse gas emission mitigation systems, like CO2, H2S and NOx removal systems. It establishes the target facility and its conceptual basic design proposal. The syngas obtained after the gasification of sterile coal is processed through specific conditioning units before entering into the combustion chamber of a gas turbine. Flue gas leaving the gas turbine is ducted to a heat recovery steam generation boiler; the steam produced within the boilerdrives a steam turbine. The target facility resembles a singular Integrated Gasification in Combined Cycle (IGCC) power station. The evaluation of the conceptual basic design according to the power output set for a maximum sterile contribution, established that rates over 95% H2S and 90% CO2 removal can be achieved. Noticeable decrease of NOx compounds can be also achieved by the use of commercial technology. A techno-economic approach of the conceptual basic design is made evaluating the integration of potential unitsand their implementation within the target facility aiming toachieve clean power generation. The criterion to be compliant with the most restrictive regulation regarding environmental emissions is setting to carry out this analysis.

Fertilization Management: Assessing New Techniques and Key Interactions to Increase Crop Yields With Less N2O Emissions

El óxido nitroso (N2O) es un potente gas de efecto invernadero (GHG) proveniente mayoritariamente de la fertilización nitrogenada de los suelos agrícolas. Identificar estrategias de manejo de la fertilización que reduzcan estas emisiones sin suponer un descenso de los rendimientos es vital tanto a nivel económico como medioambiental. Con ese propósito, en esta Tesis se han evaluado: (i) estrategias de manejo directo de la fertilización (inhibidores de la nitrificación/ureasa); y (ii) interacciones de los fertilizantes con (1) el manejo del agua, (2) residuos de cosecha y (3) diferentes especies de plantas. Para conseguirlo se llevaron a cabo meta-análisis, incubaciones de laboratorio, ensayos en invernadero y experimentos de campo. Los inhibidores de la nitrificación y de la actividad ureasa se proponen habitualmente como medidas para reducir las pérdidas de nitrógeno (N), por lo que su aplicación estaría asociada al uso eficiente del N por parte de los cultivos (NUE). Sin embargo, su efecto sobre los rendimientos es variable. Con el objetivo de evaluar en una primera fase su efectividad para incrementar el NUE y la productividad de los cultivos, se llevó a cabo un meta-análisis. Los inhibidores de la nitrificación dicyandiamide (DCD) y 3,4-dimetilepyrazol phosphate (DMPP) y el inhibidor de la ureasa N-(n-butyl) thiophosphoric triamide (NBPT) fueron seleccionados para el análisis ya que generalmente son considerados las mejores opciones disponibles comercialmente. Nuestros resultados mostraron que su uso puede ser recomendado con el fin de incrementar tanto el rendimiento del cultivo como el NUE (incremento medio del 7.5% y 12.9%, respectivamente). Sin embargo, se observó que su efectividad depende en gran medida de los factores medioambientales y de manejo de los estudios evaluados. Una mayor respuesta fue encontrada en suelos de textura gruesa, sistemas irrigados y/o en cultivos que reciben altas tasas de fertilizante nitrogenado. En suelos alcalinos (pH ≥ 8), el inhibidor de la ureasa NBPT produjo el mayor efecto. Dado que su uso representa un coste adicional para los agricultores, entender las mejores prácticas que permitan maximizar su efectividad es necesario para posteriormente realizar comparaciones efectivas con otras prácticas que incrementen la productividad de los cultivos y el NUE. En base a los resultados del meta-análisis, se seleccionó el NBPT como un inhibidor con gran potencial. Inicialmente desarrollado para reducir la volatilización de amoniaco (NH3), en los últimos años algunos investigadores han demostrado en estudios de campo un efecto mitigador de este inhibidor sobre las pérdidas de N2O provenientes de suelos fertilizados bajo condiciones de baja humedad del suelo. Dada la alta variabilidad de los experimentos de campo, donde la humedad del suelo cambia rápidamente, ha sido imposible entender mecanísticamente el potencial de los inhibidores de la ureasa (UIs) para reducir emisiones de N2O y su dependencia con respecto al porcentaje de poros llenos de agua del suelo (WFPS). Por lo tanto se realizó una incubación en laboratorio con el propósito de evaluar cuál es el principal mecanismo biótico tras las emisiones de N2O cuando se aplican UIs bajo diferentes condiciones de humedad del suelo (40, 60 y 80% WFPS), y para analizar hasta qué punto el WFPS regula el efecto del inhibidor sobre las emisiones de N2O. Un segundo UI (i.e. PPDA) fue utilizado para comparar el efecto del NBPT con el de otro inhibidor de la ureasa disponible comercialmente; esto nos permitió comprobar si el efecto de NBPT es específico de ese inhibidor o no. Las emisiones de N2O al 40% WFPS fueron despreciables, siendo significativamente más bajas que las de todos los tratamientos fertilizantes al 60 y 80% WFPS. Comparado con la urea sin inhibidor, NBPT+U redujo las emisiones de N2O al 60% WFPS pero no tuvo efecto al 80% WFPS. La aplicación de PPDA incrementó significativamente las emisiones con respecto a la urea al 80% WFPS mientras que no se encontró un efecto significativo al 60% WFPS. Al 80% WFPS la desnitrificación fue la principal fuente de las emisiones de N2O en todos los tratamientos mientras que al 60% tanto la nitrificación como la desnitrificación tuvieron un papel relevante. Estos resultados muestran que un correcto manejo del NBPT puede suponer una estrategia efectiva para mitigar las emisiones de N2O. Con el objetivo de trasladar nuestros resultados de los estudios previos a condiciones de campo reales, se desarrolló un experimento en el que se evaluó la efectividad del NBPT para reducir pérdidas de N y aumentar la productividad durante un cultivo de cebada (Hordeum vulgare L.) en secano Mediterráneo. Se determinó el rendimiento del cultivo, las concentraciones de N mineral del suelo, el carbono orgánico disuelto (DOC), el potencial de desnitrificación, y los flujos de NH3, N2O y óxido nítrico (NO). La adición del inhibidor redujo las emisiones de NH3 durante los 30 días posteriores a la aplicación de urea en un 58% y las emisiones netas de N2O y NO durante los 95 días posteriores a la aplicación de urea en un 86 y 88%, respectivamente. El uso de NBPT también incrementó el rendimiento en grano en un 5% y el consumo de N en un 6%, aunque ninguno de estos incrementos fue estadísticamente significativo. Bajo las condiciones experimentales dadas, estos resultados demuestran el potencial del inhibidor de la ureasa NBPT para mitigar las emisiones de NH3, N2O y NO provenientes de suelos arables fertilizados con urea, mediante la ralentización de la hidrólisis de la urea y posterior liberación de menores concentraciones de NH4 + a la capa superior del suelo. El riego por goteo combinado con la aplicación dividida de fertilizante nitrogenado disuelto en el agua de riego (i.e. fertirriego por goteo) se considera normalmente una práctica eficiente para el uso del agua y de los nutrientes. Algunos de los principales factores (WFPS, NH4 + y NO3 -) que regulan las emisiones de GHGs (i.e. N2O, CO2 y CH4) y NO pueden ser fácilmente manipulados por medio del fertirriego por goteo sin que se generen disminuciones del rendimiento. Con ese propósito se evaluaron opciones de manejo para reducir estas emisiones en un experimento de campo durante un cultivo de melón (Cucumis melo L.). Los tratamientos incluyeron distintas frecuencias de riego (semanal/diario) y tipos de fertilizantes nitrogenados (urea/nitrato cálcico) aplicados por fertirriego. Fertirrigar con urea en lugar de nitrato cálcico aumentó las emisiones de N2O y NO por un factor de 2.4 y 2.9, respectivamente (P < 0.005). El riego diario redujo las emisiones de NO un 42% (P < 0.005) pero aumentó las emisiones de CO2 un 21% (P < 0.05) comparado con el riego semanal. Analizando el Poder de Calentamiento global en base al rendimiento así como los factores de emisión del NO, concluimos que el fertirriego semanal con un fertilizante de tipo nítrico es la mejor opción para combinar productividad agronómica con sostenibilidad medioambiental en este tipo de agroecosistemas. Los suelos agrícolas en las áreas semiáridas Mediterráneas se caracterizan por su bajo contenido en materia orgánica y bajos niveles de fertilidad. La aplicación de residuos de cosecha y/o abonos es una alternativa sostenible y eficiente desde el punto de vista económico para superar este problema. Sin embargo, estas prácticas podrían inducir cambios importantes en las emisiones de N2O de estos agroecosistemas, con impactos adicionales en las emisiones de CO2. En este contexto se llevó a cabo un experimento de campo durante un cultivo de cebada (Hordeum vulgare L.) bajo condiciones Mediterráneas para evaluar el efecto de combinar residuos de cosecha de maíz con distintos inputs de fertilizantes nitrogenados (purín de cerdo y/o urea) en estas emisiones. La incorporación de rastrojo de maíz incrementó las emisiones de N2O durante el periodo experimental un 105%. Sin embargo, las emisiones de NO se redujeron significativamente en las parcelas enmendadas con rastrojo. La sustitución parcial de urea por purín de cerdo redujo las emisiones netas de N2O un 46 y 39%, con y sin incorporación de residuo de cosecha respectivamente. Las emisiones netas de NO se redujeron un 38 y un 17% para estos mismos tratamientos. El ratio molar DOC:NO3 - demostró predecir consistentemente las emisiones de N2O y NO. El efecto principal de la interacción entre el fertilizante nitrogenado y el rastrojo de maíz se dio a los 4-6 meses de su aplicación, generando un aumento del N2O y una disminución del NO. La sustitución de urea por purín de cerdo puede considerarse una buena estrategia de manejo dado que el uso de este residuo orgánico redujo las emisiones de óxidos de N. Los pastos de todo el mundo proveen numerosos servicios ecosistémicos pero también suponen una importante fuente de emisión de N2O, especialmente en respuesta a la deposición de N proveniente del ganado mientras pasta. Para explorar el papel de las plantas como mediadoras de estas emisiones, se analizó si las emisiones de N2O dependen de la riqueza en especies herbáceas y/o de la composición específica de especies, en ausencia y presencia de una deposición de orina. Las hipótesis fueron: 1) las emisiones de N2O tienen una relación negativa con la productividad de las plantas; 2) mezclas de cuatro especies generan menores emisiones que monocultivos (dado que su productividad será mayor); 3) las emisiones son menores en combinaciones de especies con distinta morfología radicular y alta biomasa de raíz; y 4) la identidad de las especies clave para reducir el N2O depende de si hay orina o no. Se establecieron monocultivos y mezclas de dos y cuatro especies comunes en pastos con rasgos funcionales divergentes: Lolium perenne L. (Lp), Festuca arundinacea Schreb. (Fa), Phleum pratense L. (Php) y Poa trivialis L. (Pt), y se cuantificaron las emisiones de N2O durante 42 días. No se encontró relación entre la riqueza en especies y las emisiones de N2O. Sin embargo, estas emisiones fueron significativamente menores en ciertas combinaciones de especies. En ausencia de orina, las comunidades de plantas Fa+Php actuaron como un sumidero de N2O, mientras que los monocultivos de estas especies constituyeron una fuente de N2O. Con aplicación de orina la comunidad Lp+Pt redujo (P < 0.001) las emisiones de N2O un 44% comparado con los monocultivos de Lp. Las reducciones de N2O encontradas en ciertas combinaciones de especies pudieron explicarse por una productividad total mayor y por una complementariedad en la morfología radicular. Este estudio muestra que la composición de especies herbáceas es un componente clave que define las emisiones de N2O de los ecosistemas de pasto. La selección de combinaciones de plantas específicas en base a la deposición de N esperada puede, por lo tanto, ser clave para la mitigación de las emisiones de N2O. ABSTRACT Nitrous oxide (N2O) is a potent greenhouse gas (GHG) directly linked to applications of nitrogen (N) fertilizers to agricultural soils. Identifying mitigation strategies for these emissions based on fertilizer management without incurring in yield penalties is of economic and environmental concern. With that aim, this Thesis evaluated: (i) the use of nitrification and urease inhibitors; and (ii) interactions of N fertilizers with (1) water management, (2) crop residues and (3) plant species richness/identity. Meta-analysis, laboratory incubations, greenhouse mesocosm and field experiments were carried out in order to understand and develop effective mitigation strategies. Nitrification and urease inhibitors are proposed as means to reduce N losses, thereby increasing crop nitrogen use efficiency (NUE). However, their effect on crop yield is variable. A meta-analysis was initially conducted to evaluate their effectiveness at increasing NUE and crop productivity. Commonly used nitrification inhibitors (dicyandiamide (DCD) and 3,4-dimethylepyrazole phosphate (DMPP)) and the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) were selected for analysis as they are generally considered the best available options. Our results show that their use can be recommended in order to increase both crop yields and NUE (grand mean increase of 7.5% and 12.9%, respectively). However, their effectiveness was dependent on the environmental and management factors of the studies evaluated. Larger responses were found in coarse-textured soils, irrigated systems and/or crops receiving high nitrogen fertilizer rates. In alkaline soils (pH ≥ 8), the urease inhibitor NBPT produced the largest effect size. Given that their use represents an additional cost for farmers, understanding the best management practices to maximize their effectiveness is paramount to allow effective comparison with other practices that increase crop productivity and NUE. Based on the meta-analysis results, NBPT was identified as a mitigation option with large potential. Urease inhibitors (UIs) have shown to promote high N use efficiency by reducing ammonia (NH3) volatilization. In the last few years, however, some field researches have shown an effective mitigation of UIs over N2O losses from fertilized soils under conditions of low soil moisture. Given the inherent high variability of field experiments where soil moisture content changes rapidly, it has been impossible to mechanistically understand the potential of UIs to reduce N2O emissions and its dependency on the soil water-filled pore space (WFPS). An incubation experiment was carried out aiming to assess what is the main biotic mechanism behind N2O emission when UIs are applied under different soil moisture conditions (40, 60 and 80% WFPS), and to analyze to what extent the soil WFPS regulates the effect of the inhibitor over N2O emissions. A second UI (i.e. PPDA) was also used aiming to compare the effect of NBPT with that of another commercially available urease inhibitor; this allowed us to see if the effect of NBPT was inhibitor-specific or not. The N2O emissions at 40% WFPS were almost negligible, being significantly lower from all fertilized treatments than that produced at 60 and 80% WFPS. Compared to urea alone, NBPT+U reduced the N2O emissions at 60% WFPS but had no effect at 80% WFPS. The application of PPDA significantly increased the emissions with respect to U at 80% WFPS whereas no significant effect was found at 60% WFPS. At 80% WFPS denitrification was the main source of N2O emissions for all treatments. Both nitrification and denitrification had a determinant role on these emissions at 60% WFPS. These results suggest that adequate management of the UI NBPT can provide, under certain soil conditions, an opportunity for N2O mitigation. We translated our previous results to realistic field conditions by means of a field experiment with a barley crop (Hordeum vulgare L.) under rainfed Mediterranean conditions in which we evaluated the effectiveness of NBPT to reduce N losses and increase crop yields. Crop yield, soil mineral N concentrations, dissolved organic carbon (DOC), denitrification potential, NH3, N2O and nitric oxide (NO) fluxes were measured during the growing season. The inclusion of the inhibitor reduced NH3 emissions in the 30 d following urea application by 58% and net N2O and NO emissions in the 95 d following urea application by 86 and 88%, respectively. NBPT addition also increased grain yield by 5% and N uptake by 6%, although neither increase was statistically significant. Under the experimental conditions presented here, these results demonstrate the potential of the urease inhibitor NBPT in abating NH3, N2O and NO emissions from arable soils fertilized with urea, slowing urea hydrolysis and releasing lower concentrations of NH4 + to the upper soil layer. Drip irrigation combined with split application of N fertilizer dissolved in the irrigation water (i.e. drip fertigation) is commonly considered best management practice for water and nutrient efficiency. Some of the main factors (WFPS, NH4 + and NO3 -) regulating the emissions of GHGs (i.e. N2O, carbon dioxide (CO2) and methane (CH4)) and NO can easily be manipulated by drip fertigation without yield penalties. In this study, we tested management options to reduce these emissions in a field experiment with a melon (Cucumis melo L.) crop. Treatments included drip irrigation frequency (weekly/daily) and type of N fertilizer (urea/calcium nitrate) applied by fertigation. Crop yield, environmental parameters, soil mineral N concentrations, N2O, NO, CH4, and CO2 fluxes were measured during the growing season. Fertigation with urea instead of calcium nitrate increased N2O and NO emissions by a factor of 2.4 and 2.9, respectively (P < 0.005). Daily irrigation reduced NO emissions by 42% (P < 0.005) but increased CO2 emissions by 21% (P < 0.05) compared with weekly irrigation. Based on yield-scaled Global Warming Potential as well as NO emission factors, we conclude that weekly fertigation with a NO3 --based fertilizer is the best option to combine agronomic productivity with environmental sustainability. Agricultural soils in semiarid Mediterranean areas are characterized by low organic matter contents and low fertility levels. Application of crop residues and/or manures as amendments is a cost-effective and sustainable alternative to overcome this problem. However, these management practices may induce important changes in the nitrogen oxide emissions from these agroecosystems, with additional impacts on CO2 emissions. In this context, a field experiment was carried out with a barley (Hordeum vulgare L.) crop under Mediterranean conditions to evaluate the effect of combining maize (Zea mays L.) residues and N fertilizer inputs (organic and/or mineral) on these emissions. Crop yield and N uptake, soil mineral N concentrations, dissolved organic carbon (DOC), denitrification capacity, N2O, NO and CO2 fluxes were measured during the growing season. The incorporation of maize stover increased N2O emissions during the experimental period by c. 105 %. Conversely, NO emissions were significantly reduced in the plots amended with crop residues. The partial substitution of urea by pig slurry reduced net N2O emissions by 46 and 39 %, with and without the incorporation of crop residues respectively. Net emissions of NO were reduced 38 and 17 % for the same treatments. Molar DOC:NO3 - ratio was found to be a robust predictor of N2O and NO fluxes. The main effect of the interaction between crop residue and N fertilizer application occurred in the medium term (4-6 month after application), enhancing N2O emissions and decreasing NO emissions as consequence of residue incorporation. The substitution of urea by pig slurry can be considered a good management strategy since N2O and NO emissions were reduced by the use of the organic residue. Grassland ecosystems worldwide provide many important ecosystem services but they also function as a major source of N2O, especially in response to N deposition by grazing animals. In order to explore the role of plants as mediators of these emissions, we tested whether and how N2O emissions are dependent on grass species richness and/or specific grass species composition in the absence and presence of urine deposition. We hypothesized that: 1) N2O emissions relate negatively to plant productivity; 2) four-species mixtures have lower emissions than monocultures (as they are expected to be more productive); 3) emissions are lowest in combinations of species with diverging root morphology and high root biomass; and 4) the identity of the key species that reduce N2O emissions is dependent on urine deposition. We established monocultures and two- and four-species mixtures of common grass species with diverging functional traits: Lolium perenne L. (Lp), Festuca arundinacea Schreb. (Fa), Phleum pratense L. (Php) and Poa trivialis L. (Pt), and quantified N2O emissions for 42 days. We found no relation between plant species richness and N2O emissions. However, N2O emissions were significantly reduced in specific plant species combinations. In the absence of urine, plant communities of Fa+Php acted as a sink for N2O, whereas the monocultures of these species constituted a N2O source. With urine application Lp+Pt plant communities reduced (P < 0.001) N2O emissions by 44% compared to monocultures of Lp. Reductions in N2O emissions by species mixtures could be explained by total biomass productivity and by complementarity in root morphology. Our study shows that plant species composition is a key component underlying N2O emissions from grassland ecosystems. Selection of specific grass species combinations in the context of the expected nitrogen deposition regimes may therefore provide a key management practice for mitigation of N2O emissions.

Climate Change and Restoration of Degraded Land

The United Nations Climate Change Conference, Durban 2011, delivered a breakthrough on the international community's response to climate change. In the second largest meeting of its kind, the negotiations advanced, in a balanced fashion, the implementation of the Convention and the Kyoto Protocol, the Bali Action Plan, and the Cancun Agreements. The outcomes included a decision by Parties to adopt a universal legal agreement on climate change as soon as possible, and no later than 2015. One of the decisions adopted by COP 17 and CMP 7 regard to the land use, land-use change and forestry, and invites the Intergovernmental Panel on Climate Change to review and, if necessary, update supplementary methodologies for estimating anthropogenic greenhouse gas emissions by sources and removals by sinks resulting from land use, land-use change and forestry activities under Article 3, paragraphs 3 and 4, of the Kyoto Protocol. Land degradation is a human-induced or natural process which negatively affects the productivity of land within an ecosystem. The direct causes of land degradation are geographically specific. Climate change, including changes in short-term variation, as well as long-term gradual changes in temperature and precipitation, is expected to be an additional stress on rates of land degradation. Book Topics: • Introduction to Climate Change and Land Degradation • Change Mitigation • Climate Change and Waste Land Restoration • Water Management and Planning • Erosion and Hydrological Restoration • Forest Fire Land Restoration • Polluted Soils Restoration • Combating Climate Change by Restoration of Degraded Land • Research Matters – Climate Change Governance • Advanced Statistics Climate Change and Restoration of Degraded Land is of interests to academics, engineers, consultans, designers and professionals involved in restoration of degraded lands projects.

Ranking factors affecting emissions of GHG from incubated agricultural soils

Agriculture significantly contributes to global greenhouse gas (GHG) missions and there is a need to develop effective mitigation strategies. The efficacy of methods to reduce GHG fluxes from agricultural soils can be affected by a range of interacting management and environmental factors. Uniquely, we used the Taguchi experimental design methodology to rank the relative importance of six factors known to affect the emission of GHG from soil: nitrate (NO3?) addition, carbon quality (labile and non-labile C), soil temperature, water-filled pore space (WFPS) and extent of soil compaction. Grassland soil was incubated in jars where selected factors, considered at two or three amounts within the experimental range, were combined in an orthogonal array to determine the importance and interactions between factors with a L16 design, comprising 16 experimental units. Within this L16 design, 216 combinations of the full factorial experimental design were represented. Headspace nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2) concentrations were measured and used to calculate fluxes. Results found for the relative influence of factors (WFPS and NO3? addition were the main factors affecting N2O fluxes, whilst glucose, NO3? and soil temperature were the main factors affecting CO2 and CH4 fluxes) were consistent with those already well documented. Interactions between factors were also studied and results showed that factors with Little individual influence became more influential in combination. The proposed methodology offers new possibilities for GHG researchers to study interactions between influential factors and address the optimized sets of conditions to reduce GHG emissions in agro-ecosystems, while reducing the number of experimental units required compared with conventional experimental procedures that adjust one variable at a time.

Leakage of nitrous oxide emissions within the Spanish agro-food system in 1961-2009

Abstract In this paper we examine the trends of nitrous oxide (N2O) emissions of the Spanish agricultural sector related to national production and consumption in the 1961?2009 period.The comparison between production- and consumption-based emissions at the national level provides a complete overview of the actual impact resulting from the dietary choices of a given country and allows the evaluation of potential emission leakages. On average, 1.5 % of the new reactive nitrogen that enters Spain every year is emitted as N2O. Production- and consumption-based emissions have both significantly increased in the period studied and nowadays consumption-based emissions are 45 % higher than production-based emissions. A large proportion of the net N2O emissions associated with imported agricultural godos comes from countries that are not committers for the United Nations Framework Convention on Climate Change Kyoto Protocol Annex I. An increase in feed consumption is the main driver of the changes observed, leading to a arkable emission leakage in the Spanish agricultural sector. The complementary approach used here is essential to achieve an effective mitigation of Spanish greenhouse gas emissions.