The implications of climate change on forage-based livestock systems in Scotland

The thesis examined the effects of climatic change on livestock production within Scotland. In order to achieve this, a systems model of the dairy, beef and sheep enterprises was developed. Climatic change primarily affects livestock production through its effects on forage production. Under climatic change, the model predicted that the length of the growing and grazing season will increase with the extensions occurring at both ends of the season. Relative to current climatic conditions elevated CO2 concentrations coupled with the associated changes in climate resulted in an enhancement in harvestable dry-matter yield that ranged from 20% to nearly 60% and increases in the percentage of white clover in the harvestable material by up to 126% In general, global warming is predicted to increase forage and livestock production within Scotland. However, the location of the site is also important in determining the effect of climate change as the magnitude and, in some cases, the directions of the changes varied between sites. The effects of climate change were also dependent on the actual level of changes in temperature. In addition, there were interactions between CO2 concentration and both temperature and rainfall, as well as interactions between temperature and rainfall. Although the three enterprises showed similar trends in their response to climate change, there were differences in the magnitude of the response as well as differences in the factors that resulted in significant changes. There were also differences in the response of the grazed and the ungrazed swards. This underlines the complexity of the interactions and the difficulty of extrapolating the results to other locations and to other levels of climatic conditions. The advantage of developing a model is that all these complex interactions can be captured and potentially the site - specific consequences of climate change on forage and livestock production predicted

Modelling Productivity and Nitrate Leaching in a Simulated Dairy Farm

Dairy farmers are faced with the challenge of balancing trade-offs between productivity, and hence profitability, and protection of the environment. An integrated simulation model of the dairy system has been used to explore impacts of varying fertiliser application rates and stocking densities on these trade-offs. The winter requirement for silage was found to be an important determinant of the carrying capacity throughout the year. Increasing fertiliser application rates tends to increase the carrying capacity and also reduce the degree of variability between years. However, nitrate leaching and denitrification losses increase as fertiliser and stocking rates increase. The losses from a permanent pasture tend to be higher than those observed for ley pastures. Congregation of cows in small areas results in substantial increases in leaching losses and hence increased risk of environmental damage compared to an even spatial distribution over the whole area. The modelling framework provides a tool with which to explore optimum management strategies on a practical dairy farm.Simulation de la productivité et des pertes nitriques dans un système d'élevage laitier modélisé. Les producteurs de lait sont confrontés au problème de l'établissement de l'équilibre entre la productivité, et par conséquent la rentabilité, et la préservation de l'environnement. Un modèle de simulation intégré du système laitier a été employé pour étudier l'impact de différentes doses d'engrais et de charge en animaux sur ces équilibres. Les besoins en ensilage pour l'hiver se sont avérés être une cause déterminante de la charge en bétail pour l'ensemble de l'année. L'augmentation des doses d'engrais a tendance à accroître la capacité de charge et à également réduire la variabilité interannuelle. Cependant, les pertes par lixiviation et par dénitrification augmentent avec les applications d'engrais et la charge en bétail. Les pertes à partir des prairies permanentes tendent à être plus importantes que celles observées pour les prairies temporaires. Le groupement des vaches sur des espaces réduits induit des augmentations de pertes par lixiviation et, par conséquent, a de plus grands risques de dommages environnementaux comparativement à une distribution spatiale plus uniforme, couvrant les zones entières. Le modèle fournit un outil qui permet d'explorer les stratégies optimales de gestion en production laitière

Modelling Productivity and Nitrate Leaching in a Simulated Dairy Farm

Dairy farmers are faced with the challenge of balancing trade-offs between productivity, and hence profitability, and protection of the environment. An integrated simulation model of the dairy system has been used to explore impacts of varying fertiliser application rates and stocking densities on these trade-offs. The winter requirement for silage was found to be an important determinant of the carrying capacity throughout the year. Increasing fertiliser application rates tends to increase the carrying capacity and also reduce the degree of variability between years. However, nitrate leaching and denitrification losses increase as fertiliser and stocking rates increase. The losses from a permanent pasture tend to be higher than those observed for ley pastures. Congregation of cows in small areas results in substantial increases in leaching losses and hence increased risk of environmental damage compared to an even spatial distribution over the whole area. The modelling framework provides a tool with which to explore optimum management strategies on a practical dairy farm.Simulation de la productivité et des pertes nitriques dans un système d'élevage laitier modélisé. Les producteurs de lait sont confrontés au problème de l'établissement de l'équilibre entre la productivité, et par conséquent la rentabilité, et la préservation de l'environnement. Un modèle de simulation intégré du système laitier a été employé pour étudier l'impact de différentes doses d'engrais et de charge en animaux sur ces équilibres. Les besoins en ensilage pour l'hiver se sont avérés être une cause déterminante de la charge en bétail pour l'ensemble de l'année. L'augmentation des doses d'engrais a tendance à accroître la capacité de charge et à également réduire la variabilité interannuelle. Cependant, les pertes par lixiviation et par dénitrification augmentent avec les applications d'engrais et la charge en bétail. Les pertes à partir des prairies permanentes tendent à être plus importantes que celles observées pour les prairies temporaires. Le groupement des vaches sur des espaces réduits induit des augmentations de pertes par lixiviation et, par conséquent, a de plus grands risques de dommages environnementaux comparativement à une distribution spatiale plus uniforme, couvrant les zones entières. Le modèle fournit un outil qui permet d'explorer les stratégies optimales de gestion en production laitière

Translating the multiactor approach to research into practice using a workshop approach focusing on species mixtures

International audienceThe EIP-Agri multiactor approach was exemplified during a 3-day workshop with 63 project participants from the EU H2020 funded project “RedesigningEuropean cropping systems based on species MIXtures”. The objective was to share firsthand experience of participatory research among researchers whowere mostly not familiar with this approach. Workshop participants were divided into smaller multidisciplinary groups and given the opportunity tointeract with representatives from eight actor positions in the value chain of the agrifood cooperative Terrena located in Western France. The four stages ofthe workshop were: (1) key actor interviews, (2) sharing proposed solutions for overcoming barriers, and (3) developing possible interdisciplinary concepts.Expressions of frustration were recorded serving both as a motivation for group members to become more aware of the scientific concerns andpractices of their colleagues, as well as a recognition that some researchers have better skills integrating qualitative approaches than others. Nevertheless,the workshop format was an effective way to gain a common understanding of the pertinent issues that need to be addressed to meet overall multiactorapproachobjectives. Working with the actor networks was identified and emphasized as a means to overcome existing barriers between academia andpractice in order to coproduce a shared vision of the benefits of species mixture benefits