Sustainability assessment of key european dairy cattle production systems: system identification, analysis, and greenhouse gas and nitrogen emission mitigation
- Autores: Xabier Díaz de Otálora
- Directores de la Tesis: Barbara Amon (dir. tes.), Agustín del Prado Santeodoro (dir. tes.), Fernando Estellés Barber (tut. tes.)
- Lectura: En la Universitat Politècnica de València ( España ) en 2023
- Idioma: inglés
- Tribunal Calificador de la Tesis: Ana Cristina Rufino (presid.), Salvador Calvet Sanz (secret.), Athanasia Varsaki (voc.)
- Programa de doctorado: Programa de Doctorado en Ciencia y Tecnología de la Producción Animal por la Universitat Politècnica de València
- Materias:
- Enlaces
- Tesis en acceso abierto en: RiuNet
- Resumen
During the last decades, multiple challenges have put the environmental, economic, and social sustainability of dairy cattle production systems (DPS) at risk. This Ph.D. Thesis tackles some of the sector's main challenges in terms of sustainability by developing concepts, methodologies, and strategies adapted to the particular needs of a wide range of European DPS. In particular, special emphasis is placed on evaluating the tools for sustainability assessments, the analysis and clustering of the diversity of existing production systems, and the adapted mitigation of greenhouse gas (GHG) emissions and nitrogen (N) losses at the farm scale.
This Ph.D. Thesis presents a quantitative framework that comprehensively evaluates whole-farm tools and models. The obtained results show how the models considered incorporate more indicators from the environmental pillar than those related to the economic or social sphere. In addition, this work facilitates the identification of avenues for future model developments, allowing for a more complete and detailed assessment of sustainability.
Furthermore, the results obtained allow for the identification, description, and clustering of European regions according to different typologies of production systems. The 16 representative typologies identified combine DPS's structural, productive, socio-economic, and environmental characteristics with the level of overlap with the most relevant fodder crops for dairy production at the NUTS2 scale. Furthermore, by analyzing and clustering the diversity of production systems and assessing their level of integration, this Ph.D. Thesis facilitates knowledge-based decision-making, the design and implementation of targeted and adapted emission mitigation measures, as well as the promotion of positive economic and social synergies.
Moreover, this Ph.D. Thesis highlights the strong influence of climatic conditions, structural characteristics, and management practices on N and GHG emissions associated with enteric fermentation, fields, and manure management. In terms of emission mitigation, reducing the amount of crude protein in the purchased fraction of the diet is an effective strategy to mitigate both GHG and N emissions. Additionally, implementing an anaerobic digestion plant reduces GHG emissions in all assessed DPS but increases N losses only in the intensive Mediterranean DPS. The impact of increased productivity through larger use of concentrates on N losses and GHG emissions varied depending on the farming systems examined. In this sense, the Central European semi-extensive system shows a higher potential for GHG reduction, while the Atlantic semi-extensive system accounts for better results when lowering the N losses. Similarly, shallow slurry injection effectively decreases N losses at the field level, although it increases GHG emissions in the Mediterranean DPS. Substituting urea with ammonium nitrate has different effects on GHG and N emission intensity, with greater potential for mitigation in the Atlantic semi-extensive system. Lastly, rigid slurry covers effectively reduces N losses during storage with minimal impact on GHG emissions. Furthermore, this Ph.D. Thesis shows how the cumulative application of mitigation measures leads to positive synergies in reducing the overall emissions of the farm.
