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Conventional Mediterranean vineyards from the Montes de Málaga (Axarquía region, Spain) are characterized by high average temperatures, extreme rainfall events during autumn and winter, elevated stoniness and steep slopes (20–50°). Traditionally, several problems of high soil loss, rill and ephemeral gully generation, and elevated runoff are observed by farmers, which are increasing land degradation processes and a decrease of the productivity. According to this, the main aims of this paper were: i) to quantify the initial soil loss, surface flow and infiltration processes; ii) to characterize and describe the hydrological and geomorphological dynamics; iii) to detect the key factors, which control the soil erosion processes. For this purpose, a combined methodology was applied, using soil analysis, a small portable rainfall simulator and a Guelph permeameter on one experimental plot cultivated with vineyards with steep slopes. Results showed a high variability of soil erosion and permeability processes. Soil analysis showed an elevated concentration of silt particles and stoniness, with higher contents of sand particles between 0 and 5 cm, and clays from 5 cm. With a Guelph permeameter, high average of permeability and saturated hydraulic conductivity with elevated standard deviation were observed. Furthermore, an increase of these parameters from the upper to the foot slope was registered. By using rainfall simulations, on the upper and the foot slope positions the highest runoff coefficient and soil loss were registered. The most elevated peak of sediment concentration was obtained on the middle slope. In general, high infiltration coefficients between 66.5 and 100% were observed. In conclusion it was observed that the activation of the soil erosion processes was due to the distribution of the surface soil components (high roughness, several cracks and high stoniness and silt content), the steep slopes and the impact of the soil traditional tillage practices. These Mediterranean hillslope vineyards registered a mixed Hortonian-Hewlettian model, which combines surface and sub-surface flow conditioned by the micro-topographical changes and its saturation degree. [ABSTRACT FROM AUTHOR]

Abstract: Understanding soil dynamics is essential for making appropriate land management decisions, as soils can affect the carbon content from the atmosphere, emitting large quantities of CO2 or storing carbon. This property is essential for climate change mitigation strategies as agriculture and forestry soil management can affect the carbon cycle. The Mediterranean dehesa (Mediterranean grassland ecosystem with scattered oak trees — grazing system with Quercus ilex spp. ballota) is a silvopastoral system that integrates forestry, agricultural and livestock practices. The dehesa is characterized by the preservation of forest oaks that provide environmental services including carbon capture and storage. This paper shows the relationships between soil properties and soil organic carbon (SOC) in two soil types: Cambisols (CM) and Leptosols (LP), with two management systems: organic farming (OF) for 20years and conventional tillage (CT) in a Mediterranean dehesa of southern Spain without cropping. An analysis of 85 soil profiles was performed in 2009 in Los Pedroches Valley (Cordoba, southern Spain). The SOC stock (SOC-S) was greater in CM (75.64Mgha−1) than in LP (44.01Mgha−1). Physical parameters were the main variables affecting soil development. SOC-S was very similar in OF and CT (CM [74.90Mgha−1-CT; 76.39Mgha−1-OF] and LP [44.77Mgha−1-CT; 43.25Mgha−1-OF]). Data analysis showed that management practices had little effect on SOC storage in the study zone. Significant differences between soil types and management practices were found in SOC content for different horizons. The stratification ratio was >2 in both soils types (CM and LP) and management systems (OF and CT). These results indicate that the soil is of high quality, and that management practices have little influence on SOC-S in Los Pedroches Valley. [Copyright &y& Elsevier]