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Soils have the capacity to store three times more carbon (C) than the atmosphere. This fact has focused scientific and governmental attention because it is one way to mitigate climate change. However, there comes a time when the capacity of soils to store C reaches a limit, considering soil organic carbon (SOC) saturation. In the Mediterranean area, agricultural soils are traditionally exposed to conventional tillage (CT), causing soil properties and quality degradation. Therefore, this study aimed to determine whether CT modifies the carbon storage capacity (carbon saturation), linked to soil mineral fractions 2000 µm) of 38.6% in the Bw horizon; however, in the small macro-aggregates (2000–250 µm), an increase in SOC concentration over time, of 33.5%, was observed in the Ap and Bw horizons. This increasing trend continued in the fine soil fractions. Concerning SOC bound to the fine mineral fraction (

This study aims to show the effect of conventional tillage (CT) in olive orchards in the medium term (15 years) on carbon (C) storage considering the complete soil profile, on the soil C sequestration and stabilisation capacity and on the viability for the achievement of Objective 4‰. The results obtained showed important losses in soil organic carbon (SOC) and SOC stock (SOC-S), with a significant loss of total SOC-S of 42.3%. Concerning the SOC and the SOC-S linked to the fine soil fraction (20 μm), the evolution over time led however to a SOC increase in depth (BC and C horizons) of 58.3% and 20.9% and increases in SOC-S of 17.2%, 34.7% and 27.3% for the Ap, BC and C horizons, respectively. Finally, it was seen that the goals set by the 4‰ initiative were not met, as losses of 2.1 Mg C ha

Agricultural activities generate CO2, CH4, and N2O, affecting the global climate and the sustainability of agricultural production systems. This topic is essential in those areas where agriculture has caused soil decarbonization. The soil can regenerate by implementing sustainable soil management (SSM), and this regeneration is finite. Therefore, it is necessary to determine the maximum carbon (C) storage capacity to establish the most SSM for soil recarbonization. This research analyzes the C storage capacity in soils with rainfed olive groves and traditional tillage in the largest olive-oil-producing area in the world (Jaén, Andalusia, Spain). The results show that these soils had low soil organic C (SOC) content, ranging from 5.16 g kg−1 (topsoil) to 1.60 g kg−1 (subsoil) and low SOC stock (SOC-S) (43.12 Mg ha−1; 0–120 cm depth). In addition, the SOC fractionation showed that the highest SOC concentrations were in the particulate organic C form. The SOC-S linked to the fine mineral fraction (

The short- and medium—long-term effects of management and hillside position on soil organic carbon (SOC) changes were studied in a centenary Mediterranean rainfed olive grove. One way to measure these changes is to analyze the soil quality, as it assesses soil degradation degree and attempts to identify management practices for sustainable soil use. In this context, the SOC stratification index (SR-COS) is one of the best indicators of soil quality to assess the degradation degree from SOC content without analyzing other soil properties. The SR-SOC was calculated in soil profiles (horizon-by-horizon) to identify the best soil management practices for sustainable use. The following time periods and soil management combinations were tested: (i) in the medium‒long-term (17 years) from conventional tillage (CT) to no-tillage (NT), (ii) in the short-term (2 years) from CT to no-tillage with cover crops (NT-CC), and (iii) the effect in the short-term (from CT to NT-CC) of different topographic positions along a hillside. The results indicate that the SR-SOC increased with depth for all management practices. The SR-SOC ranged from 1.21 to 1.73 in CT0, from 1.48 to 3.01 in CT1, from 1.15 to 2.48 in CT2, from 1.22 to 2.39 in NT-CC and from 0.98 to 4.16 in NT, therefore, the soil quality from the SR-SOC index was not directly linked to the increase or loss of SOC along the soil profile. This demonstrates the time-variability of SR-SOC and that NT improves soil quality in the long-term.

The urgent need to implement agricultural systems that provide greater sustainability and resilience to the challenges of the climate change process has meant that alternative paradigms for agri-food systems and agriculture have become more relevant in recent times. In this study, we present the building process and consolidation of an agro-ecological project (Extiercol) in a rural area of southern Spain, with a prolonged depopulation process and close connections to nearby urban areas. Through participatory action research, the specific objectives of this study are (1) to describe the agroecological collective process from its creation by a youth association to its establishment as a viable agricultural project, (2) to identify the drivers for the development of this type of transition process towards agricultural sustainability and (3) to analyse urban-rural alliances in the establishment of agroecological projects. Finally, the replicability of this project was assessed, with a special focus on the main barriers to be addressed in order to implement this agricultural system such as difficult to land access or a negative perception of sustainable management by farmers. Through this study we have shown how the connection between the food production area and nearby urban areas can be achieved through an agroecological project.

The spatial distribution of soil organic carbon (SOC) is essential to estimate the SOC reserves. Therefore, the soils ability to store organic carbon is a key factor for climate regulation and for other soil functions. The soil management and the topographic position play an important role in SOC variation, especially when the landscape is not uniform (Mediterranean areas). Many researches have explored the SOC distribution according to topographic position in hillsides for long-term, but very few studies have focused on the short term. Therefore, it is necessary to know, the changes that taking place in the soil due to land management change (LMC) in these irregular surfaces for sustainable agricultural production and its implications on climate change regulation. This study aims to assess the influence of topographic position and LMC on SOC stock (SOC-S) in Mediterranean olive groves (OG) soils in short term (2 years). In this line, three experimental plots were selected in three topographical position (summit - S, backslope - B and toeslope - T). In these plots, the land management was modified from conventional tillage (CT) to no tillage (NT) with application of pruned olive branch chippings branches and vegetation cover (spontaneous vegetation) in the OG streets. The studied soils did not show important changes due to LMC in their physical properties for short term, in addition, these soils were characterized by low organic matter content (1.2%). LMC caused a SOC reduction in surface, and a SOC increase in the Bw horizon. The N concentrations showed a similar trend to SOC and the C:N ratios were highly variable (4.37: C horizon-NT-S; 13.45 Bw/C horizon -CT-B). Normally, the SOC-S concentrations decreasing in depth. LMC for two years showed soil carbonization (S and T position) and decarbonization (B position) processes. The SOC-S increased 1.88 Mg ha

La preocupación por el medio ambiente, ha originado que las universidades ofrezcan titulaciones relacionadas con este tema, como es el caso del Grado en Ciencias Ambientales. El uso de las tecnologías en la enseñanza se considera un método que refuerza la continuidad de los temas que se trabajan en el aula y que consigue que el flujo de los contenidos educativos sea más dinámico e interactivo. En este trabajo se diseña y crea material práctico de ayuda para la asignatura de Sistemas de Gestión y Auditorías Ambientales, de 3º del grado en Ciencias Ambientales. El objetivo es proporcionar de manera innovadora la información necesaria para que los alumnos sean capaces de comprender el contenido práctico de esta asignatura con mayor facilidad. En los resultados la mayoría de los alumnos coincidieron en que es un material didáctico, explicativo, aclaratorio y de gran ayuda para quienes por primera vez conocieron que es un Sistema de Gestión Ambiental. Este recurso ha proporcionado al alumnado conocimientos previos que suponen una ventaja a la hora de comprender la asignatura, en comparación con alumnos de cursos anteriores que no contaban con este material

Carbon sequestration in agricultural soils has been defined as a positive strategy in the mitigation of global warming. The selection of the appropriate soil management system to achieve this goal is fundamental. In this study the effect of two tillage treatments, conventional tillage (CT) and no tillage with bare soil (NT) was analyzed in the complete soil profile (by horizons) in a rainfed olive grove under Mediterranean conditions. The objective was to determine the influence of treatments on soil aggregation and organic carbon (OC) distribution within aggregate fractions both in the surface horizon (0–32.7 cm in CT and 0–21 cm in NT) and in depth (32.7–119.7 cm in CT and 21.7–110 cm in NT) (Bw, BC and C horizons). Soil samples from all horizons were separated into four aggregate-size fractions: large macroaggregates (>2000 μm), small macroaggregates (250–2000 μm), microaggregates (53–250 μm), and silt + clay (

The knowledge about land management effects on soil capacity to store carbon is necessary to planning effective strategies by managers and decision-makers. In this study we analyzed the land use change (LUC) effects on soil organic carbon stocks (SOC-S) for long term in the Sardinia region - Italy (Mediterranean area). Throughout the 20th century, the studied area has undergone different LUC. The first LUC was in 1938, from forest to agricultural land under three different uses: vineyards, hay crop and pasture, later (1966) some of this agricultural land were abandoned to seminatural ecosystem (second LUC). The different LUC affected to SOC-S causing decarbonization, carbonization and recarbonization processes along the soil profile. The different land uses studied chronologically were: i) natural forest - cork oak forest (Cof), ii) tilled vineyard (Tv), iii) no tilled grassed vineyard (Ntgv), iv) hay crop (Hc), v) pasture - silvopastoral and silvoarable practices (P), and vi) former vineyard - vineyards abandoned and naturally revegetated (Fv). The first LUC (Cof to Tv, Ntgv, Hc and P) caused 5.1% and 37.5% reduction on SOC-S for Tv and Ntgv (soil decarbonization), however, the SOC-S increased 47.1% and 51.3% for Hc and P respectively (soil carbonization). The second LUC (Tv and Ntgv to Fv) increased the SOC-S on average 66.3% (soil recarbonization). In general, these effects were observed principally in depth. This study shows the importance of land use and LUC with respect to SOC-S, and that the human action can degrade and/or regenerate the soil, affecting to soil functions. Consequently, is necessity to promote good environmental practices to improve the soil functions and to reduce the greenhouse gases (ecosystem services). On the presumption that the SOC sequestration through of agricultural management can reduced the atmospheric CO2 concentration (4p1000 target in the XXI Conference of the Parties – Paris, 2015). Therefore, the soils regeneration via carbonization and/or recarbonization is an opportunity to prevent the climate change.

The short- and medium—long-term effects of management and hillside position on soil organic carbon (SOC) changes were studied in a centenary Mediterranean rainfed olive grove. One way to measure these changes is to analyze the soil quality, as it assesses soil degradation degree and attempts to identify management practices for sustainable soil use. In this context, the SOC stratification index (SR-COS) is one of the best indicators of soil quality to assess the degradation degree from SOC content without analyzing other soil properties. The SR-SOC was calculated in soil profiles (horizon-by-horizon) to identify the best soil management practices for sustainable use. The following time periods and soil management combinations were tested: (i) in the medium-long-term (17 years) from conventional tillage (CT) to no-tillage (NT), (ii) in the short-term (2 years) from CT to no-tillage with cover crops (NT-CC), and (iii) the effect in the short-term (from CT to NT-CC) of different topographic positions along a hillside. The results indicate that the SR-SOC increased with depth for all management practices. The SR-SOC ranged from 1.21 to 1.73 in CT0, from 1.48 to 3.01 in CT1, from 1.15 to 2.48 in CT2, from 1.22 to 2.39 in NT-CC and from 0.98 to 4.16 in NT; therefore, the soil quality from the SR-SOC index was not directly linked to the increase or loss of SOC along the soil profile. This demonstrates the time-variability of SR-SOC and that NT improves soil quality in the long-term.

Olive groves are one of the most important agro-systems in the Mediterranean basin, and the Andalusia region produces the highest quantity of olive oil in Europe. The aim of this work was to evaluate the long-term (15 years) influence of two management practices in olive orchards— conventional tillage (CT) and no tillage with bare soil and herbicide application (NT + H)—on soil physical properties, infiltration capacity, erosion rates, and soil productivity. In addition, the short-term (2 years) influence of no tillage with cover crop management (NT-CC) on these parameters was also assessed. In the study area, CT and NT + H management practices showed unsustainable erosion values, 9.82 and 13.88 Mg ha􀀀1 year􀀀1, respectively, while NT-CC inclusion decreased the erosion rates (2.06 Mg ha􀀀1 year􀀀1). The implementation of NT-CC not only reduced erosion rates but also caused a change in the trend of soil productivity loss observed under CT and NT + H. In this sense, NT-CC showed a positive influence on soil quality. However, tillage removal led to a significant reduction in the infiltration capacity of soils under NT + H and NT-CC, which will be a serious handicap for water storage in an environment with continuous processes of water deficit.

Olive groves are one of the most important agro-systems in the Mediterranean basin, and the Andalusia region produces the highest quantity of olive oil in Europe. The aim of this work was to evaluate the long-term (15 years) influence of two management practices in olive orchards— conventional tillage (CT) and no tillage with bare soil and herbicide application (NT + H)—on soil physical properties, infiltration capacity, erosion rates, and soil productivity. In addition, the short-term (2 years) influence of no tillage with cover crop management (NT-CC) on these parameters was also assessed. In the study area, CT and NT + H management practices showed unsustainable erosion values, 9.82 and 13.88 Mg ha􀀀1 year􀀀1, respectively, while NT-CC inclusion decreased the erosion rates (2.06 Mg ha􀀀1 year􀀀1). The implementation of NT-CC not only reduced erosion rates but also caused a change in the trend of soil productivity loss observed under CT and NT + H. In this sense, NT-CC showed a positive influence on soil quality. However, tillage removal led to a significant reduction in the infiltration capacity of soils under NT + H and NT-CC, which will be a serious handicap for water storage in an environment with continuous processes of water deficit.