• Título:  AGROFORESTRY INNOVATION AND CAP, IMPACT ON CLIMATE CHANGE, BIOECONOMY AND CIRCULAR ECONOMY
• Autor:  Rodríguez Rigueiro, Francisco Javier
• Universidad:  Universidad de Santiago de Compostela
• Departamento:  Escuela de Doctorado Internacional (EDIUS)
• Fecha de Lectura:  12/02/2021
• Mención Europeo / Mención Internacional: concedido
• Programa de doctorado:  Programa de Doctorado en Investigación Agraria y Forestal por la Universidad de A Coruña y la Universidad de Santiago de Compostela
• Dirección: 
  • Mosquera Losada, María Rosa (DIRECTOR)
  • Ferreiro Domínguez, Nuria (CODIRECTOR)
• Tribunal: 
  • Romero Franco, Rosa (PRESIDENTE)
  • ROCA PÉREZ, LUIS (SECRETARIO)
  • Pantera , Anastasia (VOCAL)
• Descriptores: 
  • ORDENACION DE MONTES
  • ORDENACION DE PASTIZALES
  • POLITICA AGRICOLA
  • CAMBIO CLIMATICO
• Localización:  BIBLIOTECA XERAL USC
• 515646_1301332.pdf
• Resumen:
  The European Union (EU), defines agroforestry in Pillar II Regulation 1305/2013 as a land-use system in which woody perennials (trees and shrubs) are grown in combination with agriculture on the same land. The beneficial effects of agroforestry have been widely recognised, providing a large set of options to buffer climate change and extreme climatic conditions or events, prevent groundwater contamination, improve nutrient re-cycling and preserve biodiversity. The excess of use of chemicals and the unsustainable land management caused degradation of needed agriculture resources such as soil or water with significant environmental consequences: as water pollution, tree destruction, soil degradation, depletion and misuse of natural resources, loss of biodiversity and lower farm resilience to climate and market changes. To face these challenges, future CAP pursues linking farming systems to the delivery of Ecosystem Services mainly related to productive, environmental and social aspects. Post-2020 CAP objectives are mainly focused on fighting climate change (40% of the next CAP budget), increase farm sustainability, protect natural resources, support farm income and resilience to enhance food security, increase farm competitiveness through research, technology, digitalisation and provide a better farmer position in the value chain trying to engage young farmers. Nowadays, within the frame of the COVID-19 pandemic crisis, European Institutions acknowledge the importance of investing in nature protection, restoration and the transition of current unsustainable agricultural practices towards sustainable farming practices aiming at reaching climate neutrality in farms as key for Europe¿s economic recovery. Agroforestry is a land use system that can be implemented at plot, farm and landscape level. When developed at the landscape level, circularity linked to mixed farming systems (MFS) is key to foster sustainability across Europe. The potential of the implementation and, therefore, the delivery of benefits from MFS and agroforestry is enormous based on previous inventories. Thus, arable crops, permanent grasslands and permanent crops as agroforestry is only used in the 0,1%, 10% and 0,1% of these types of land use in Europe, respectively. In Europe, the Mediterranean biogeographic region is particularly exposed to climate change effects. Conventional intensive practices result in biodiversity loss, which is linked to climate change and intensification leading to ecosystem degradation and reduced crop yields as part of a wider range of economical and social damages. In this regard, the European Commission estimated a toll of €3.5-18.5 trillion per year in the 1997-2011 period, related to ecosystem services losses and €5.5-10-5 trillion per year as a consequence of land degradation. AF implementation in areas with elevated environmental pressure, usually linked to intensive agricultural management, could promote a set of environmental benefits and encourage farm profitability. LUCAS (Land Use Cover Aerial Frame Survey) is a survey that collects harmonised and comparable data of the entire EU territory, based on statistical estimators to provide a wide range of information on European land cover and land use. By using the LUCAS dataset, cropland, grassland, shrubland and woodland were recognised as dominant land covers in EU-28. As sustainable land use and climate-smart agriculture technique, agroforestry is supported by several international organization, emerging as a promising tool in the policy framework. Thus, considering the challenges Europe is facing related to climate change and biodiversity loss, the European Green Deal appeared as a roadmap aiming ¿to transform EU into a fair and prosperous society, with a resource-efficient and competitive economy with no net emissions of greenhouse gases in 2050¿ and ¿protect, conserve and enhance EU¿s natural capital protecting health and well-being of citizens from environmental-related risks¿. For that purpose, the European Green Deal collects a set of six policies and measures intending to fulfil United Nation¿s 2030 Agenda. The Farm to fork strategy, the EU Biodiversity Strategy for 2030 and the new Circular Economy Action Plan are key Europe¿s Green Deal mainstays in which agroforestry come along as a potential solution. Phosphorous, nitrogen and potassium are key nutrients for agricultural production and, in the case of phosphorus, a non-renewable element which seriously compromises food production in the close future due to the ¿peak phosphorous¿ as its reserves decrease while global demand increases. In contrast, sewage sludge and biofertilizers are considered as an enormous and sustainable source of nutrients if correctly managed. The EU Bioeconomy Strategy and the Zero Waste Programme on circular economy are the renewed impetus result of previous EU legislation responding to increasing needs, scientific call to action and collective consciousness on environmental degradation. As a result of the application of the EU Directives 86/278/CEE and 91/271/CEE, urban areas over 15000 inhabitants were compelled to treat wastewater, producing consequentially a substantial amount of sewage sludge that was needed to be managed and would increase in the upcoming years. The UE Directive 86/278/CEE was related to the employment of this sewage sludge on agricultural land and transposed to local legislation in Mediterranean regions such as Spain (R.D. 1310/1990) seeking for sustainable and safe employment of this new input avoiding problems related to pathogens spread and heavy metals contamination. Within the bioeconomy and circular economy concepts, sewage sludge plays a vital role in the EU, allowing to close the loop and maximize the use of the resources created by the necessity of reducing water pollution and the upgrade on sewage sludge treatment, which provides an added-value product to consider for replacing costly inorganic fertilizers and deal with future nutrients scarcity agricultural issues. Agroforestry systems provide a large set of responses for agriculture sustainability, addressing through a holistic approach the European Institutions bioeconomy and circular economy propositions by linking rural and urban areas in several bidirectional ways. Agroforestry is an intensive practice, needing for an elevated nutrient supply due to the high extractions originated by both woody perennials and the herbaceous vegetation. However, the nutrient efficiency of agroforestry (the proportion of what is extracted compared with what is added) is higher than in monocrops, increasing biomass production per unit of land. ¿Fresh¿ sewage sludge use in agriculture is forbidden in Europe, being necessary to treat it through liming, compositing or digestion (either anaerobic and aerobic) in order to reduce pathogens and improve its quality. Sewage sludge most common treatments are anaerobic digestion and composting, being the ones promoted by the EU to be used in agriculture. Added to the previously stressed important contribution on nutrients addition to soil, when correctly managed, sewage sludge works as an important source of organic matter, boosting and upgrading soil fertility, improving soil structure and contributing to climate change mitigation by promoting carbon storage in soil and silvopastoral system understory and trees. Furthermore, calcium and organic matter content on sludge helps to enhance soil pH and neutralize aluminium toxicity in acidic soils, like those of Galicia. Several studies suggested also an increase in pasture production linked to sewage sludge fertilization in silvopastoral systems. On the other hand, sewage sludge contains itself significant amounts of heavy metals such as copper and zinc, which could create important toxicity problems if the mean content in the soil (based on their parent material origin) is surpassed. The higher heavy metal content in sewage sludge than in the soil led the European Commission to set limits on heavy metals contents on soil and seek for further regulations that were finally not approved. In this sense, the New Circular Economy Action Plan works in a proposal to review the Directive 86/278/EEC and update it in the frame of scientific knowledge increase. Thus, it is key to assess the state of the soils previously to sludge addition in order to measure fertilization requirements and obtain data on pH and heavy metals content in soils which should be linked to the parent rock material to estimate the maximum amounts of heavy metals that can be added in order to maintain soil health. This will reduce the human and animal health problems linked to heavy metals intake through the trophic chain and contributing to a safe circular economy, food security and sustainability as a whole. The objective of this PhD is to provide a global analysis on the current status of the two most important agroforestry practices in the Mediterranean region of Europe: silvoarable and silvopasture in arable and pasture areas and to evaluate the most extensively used farm management technique through a circular economy practice which is the recycling through fertilization with urban sewage sludge of a silvopasture system in Galicia. The general objective consists of three specific aims pursuing to analyze the extent of silvoarable practices as well as the deployment and implementation of policies carried out in 27 Rural Development Programmes (Pillar II) within 2014-2020 CAP framework, in the Mediterranean areas of Europe to understand how (i) silvoarable practices are promoted and provide insights to the Mediterranean Member States to develop better policies for agroforestry adoption in Europe within the Future 2021-2027 CAP framework where payments will be based on results. The second specific objective is to evaluate the current situation of permanent grasslands in the Mediterranean area of Europe as well as the rural development programmes fostering silvopasture to better understand how sustainable land use systems are promoted and provide insights to foster silvopasture across Europe. Finally, the third specific objective deals with (iii) the evaluation as a practical approach, the changes in soil chemical (pH) and biological (organic carbon) properties (pH and OM), quantifying the tree growth (dominant height and tree canopy) and establishing relationships between the variation of soil chemical and biological properties and the tree growth during the period 1998-2012 in a silvopastoral system established on an acidic forest soil under P. radiata fertilized with sewage sludge 14 years ago. Main conclusions highlight that the Mediterranean area of Europe is being dominated by the anthropogenic pressure which has been modified in the last century after the green revolution causing intensification in some areas but also land abandonment in the last decades in other areas. This makes that most of the agroforestry practices (both silvopasture and silvoarable) are placed in the West Mediterranean area of Europe in the western provinces of Spain and Portugal. In the last decades, land abandonment, as well as the afforestation and reforestation policies, caused a recovery of oaklands in the Mediterranean areas, whose understory is increasing and causes a lot of social challenges related with forest fires that became exacerbated by climate change. Agroforestry can be implemented in both forest and permanent crops land use. With regard to permanent crops, olive trees are the most representative woody perennial when agroforestry is implemented in arable lands associated to silvoarable practices to optimize the use of nutrients but also to protect soil erosion increasing the sustainability of olive orchards. On the other hand, oaklands are the most important woody perennial when agroforestry is implemented as silvopasture to extend the grazing period as a result of the benefit they cause in pasture production and as a feed resource (acorn). However, most of the regions have a low extent of silvopasture and can be linked to a high (intensive agriculture) and low (abandonment) anthropogenic pressure. Besides Oaklands, conifers are also dominated in some Mediterranean regions, but the extent of agroforestry in these areas is rather low because as pioneer species, pines are planted in marginal areas with low productivity to feed livestock and they do not provide extra feed to livestock systems such as the oaks (acorns). The potential extent of silvoarable agroforestry practices delivering ecosystem services in the Mediterranean area of Europe is enormous because of the reduced currently extent that this sustainable land use system has in both arable and permanent grassland lands. With regard to silvoarable practices, this type of land use should be promoted by the CAP considering the promotion of the extension services activities but also the development of adequate supply and value chains within The Farm to Fork and EU Bioeconomy Strategy to fulfil the European Green Deal promoted by the European Commission. Taking into account silvopasture, most of the silvopasture measures related to silvopasture are adapted to the local necessity, mainly associated with regeneration and maintenance in the managed dehesas but linked to forest fire prevention through silvopasture promotion in the majority of the Mediterranean regions of Europe. The benefits that agroforestry provides are generally acknowledged in most of the Mediterranean area of Europe where policy foster their maintenance of the establishment, however, the budget allocated to these policy measures is rather small. Most of agroforestry practices implemented in arable lands are linked to landscape features funded through the implementation of the agro-environment measure 10.1. The large set of ecosystem services that agroforestry provides is key for the European transition towards more sustainable land use systems, which makes necessary to promote agroforestry and circular economy linked to sewage sludge through the implementation of living labs, increase of technical knowledge among farmers, to provide tools to compare the best business options including the development of value chains for woody perennial products, as well as to develop knowledge systems associated to adequate extension services where research experiments, as well as innovative farms, can be used to spread the agroforestry. Tools linked to foster extension services, operational groups and eco-schemes associated with agroforestry should be promoted in the post 2020 CAP. Managing agroforestry is more complex than an exclusively arable monocrop or a forest stand which has a lower demand for inputs. Agroforestry is an intensive farm use system that increases biomass production per unit of land therefore it should be linked to higher fertilizer use, that can come from urban areas as, for example, sewage sludge. Sewage sludge improves tree growth and therefore increases biomass production per unit of land thanks to the increase of soil fertility it causes if adequate doses, indeed below the heavy metal contamination potential, are used. However, sewage sludge is not currently promoted to be used as fertilizer due to the lack of understanding of its potential. The use of sewage sludge positively affected tree growth as the tree was benefited from the very beginning when its growth rate was very high, however, the extraction of cations was not compensated by the early sewage sludge addition and increased soil acidity in an area where rainfall and rock parent material make soils to become acidic. This suggests that tree growth may be benefited from additional sewage sludge application mostly with low doses. Our results show that it seems advisable to apply additional amendments with higher pH than the soil (lime, sewage sludge) in the middle-ending years of the tree plantation to maintain adequate ranges of soil pH and SOC to compensate for the cation extractions by trees. Tree growth increases cations extraction from soil and modifies the understory microclimate which decreased the levels of soil pH and SOC in the soil over time. However, a positive effect of the fertilisation with SS on soil pH and SOC is observed, mainly in the case of the high doses of SS on pH, which did not compensate for the cations extraction from the soil by the trees, mainly in the years after the application of SS into the soil. Tree age and canopy closure is the main driver to increase soil carbon in the soil. Finally, the levels of SOC varied depending on weather conditions variability, control plots should be established to check if the managed plots by the farmers increase the SOC compared with the unmanaged plots, regardless of the weather conditions in order to account the benefit of the practices. Eco-schemes deliver an innovative opportunity to care for the environment and climate, thus supporting the transition towards more sustainable farming systems and contributing to the net-zero emissions in the agriculture sector in 2050, which should start in the post 2020 CAP.