CREAF

Sown forage mixtures have shown, experimentally, advantages in comparison with monocultures in terms of goods and services. Among the most relevant benefits, researchers have tested: high productivity and quality forage, enhanced yield stability, decreased invasibility by pests and diseases, reduced nitrogen need, decreased greenhouse gas emissions, increased resource use efficiency. The assumption is that mixtures increase soil fertility and water use efficiency. Therefore, a positive effect of mixtures on soil biodiversity and function is expected. However, a better understanding about the expected positive effect of mixtures on soil water use and fertility conservation under drought and other extreme conditions is still needed in vulnerable climates including the Mediterranean. Furthermore, in addition to intensively managed sown grasslands, there is a lack of information about the effects of grazing on soil carbon and fertility conservation in extensively used mixed systems. Extensive grazing systems are extremely important in many Mediterranean countries, and are known to provide numerous ecosystem services in terms of high diversity, soil organic carbon sequestration, water regulation; not to mention human livelihoods in rural areas, sometimes remote. However, there might be barriers to the implementation and spread of sown mixtures, and those could range from management difficulties and seed availability, to market demands. 

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SUSFORAGE proposes the establishment of 5-6 Case-Study Regions across a climatic gradient where socio-ecological surveys will be carried out and forage swards will be established. The swards will include a range of sown proportions and monocultures of the most commonly used forage species to develop models of optimal adaptive mixture proportions under given climatic conditions. Several ecological indicators will be measured at all sites during the development of the systems: yield, forage quality, water and nitrogen use efficiency by chemical and isotopic techniques, soil fertility, soil organic carbon storage, soil activity and diversity by PLFAs and metagenomics, system stability by comparing the benefits throughout time. At the same time, detailed socio-ecological surveys will be carried out with stakeholders in selected villages in the case-study regions to determine local perceptions on sown mixtures. Overall the SUSFORAGE project will contribute to enlarge the information of the benefits of sown mixtures, particularly in Mediterranean dry areas and under grazed and ungrazed conditions, in a vulnerable region with climate extremes. We will provide a model to determine the optimal proportions of different types of forage species locally adapted, belonging to different functional types, under different climate scenarios. In addition, we will provide a socio-ecological model including perceived benefits and constraints by local populations, and a plan to implement the tested sown systems at large scales in the Case-Study regions.We will derive general recommendations applicable to wider regions in the Mediterranean. Combining innovative methodologies, we will demonstrate if sown mixtures are indeed a solution for mitigation and adaptation to climate change in Mediterranean areas as expected, and the limits and constraints to their widespread distribution. 

Proyecto PCI2021-121971 financiado por MCIN/AEI /10.13039/501100011033 y por la Unión Europea NextGenerationEU/PRTR