Pedological characterization of old mountain geomorphological surfaces in Castilla-La Mancha (Spain) and their potential for sustainable viticulture

Abstract

The “rañas and rañizos” are Plio-Quaternary landform typical of the Iberan Penisula on which singular soil develops and evolve that are considered unique in Europe (Espejo, 1987; Martín-Serrano, 1991). They are characterized mainly by sedimentary deposits containing quartzite gravels embedded in a clay matrix. Considering the climatic evolution of the Iberian Peninsula (with a foreseeable increase in average temperatures and water scarcity), the use of these mountainous formations for viticulture may serve as a strategy to address the impact of climate change on Castilla-La Mancha region.

In this study, a total of 19 soils profiles (corresponding to three wineries participating in the research: Finca Rio Negro in Cogollugo, Guadalajara; Finca “Valle del Rosalejo” in Anchuras, Ciudad Real; and “Dehesa El Molinillo” in Retuerta del Bullaque, Ciudad Real) were analyzed. They are located at altitudes ranging from 616 m.a.s.l. at “Valle del Rosalejo” to 972 m.a.s.l. at “Finca Río Negro”

From a physicochemical standpoint, and based on their typical horizon sequence (Ap-Bt-C or Ap-Bw-C), these soils can be classified as deep, well-developed soils (the average thickness of the A horizon is 25.4 cm; while the B horizons have an average thickness of 47.4 cm). Their pH is slightly acidic, with higher values in the surface horizon (6.9) than in the subsurface horizon (5.9). They are non-saline soils, with an average electrical conductivity of 0.10 dS/m. The clay content is higher in the subsurface horizons than in the surface horizons (39.8% vs. 30.4%). The average cation exchange capacity of the subsurface horizons is 30.4 cmol⁺/kg. Regarding organic matter content, the soils of these vineyards contain an average of 1.9%, which is considered a normal value for soils in Castilla-La Mancha. The soils studied are mostly classified as Alfisols, although Inceptisols have also been found (Soil Survey Staff, 2022).

Based on the studies conducted on these estates and the data obtained, it can be concluded that raña soils support the development of vineyards that produce high-quality wines. This is reflected in the recognition (and registration in the European Union) of these wineries under the differentiated quality status of “Pagos Vitícolas.” highlighting their potential for viticultural quality production.

Given the changing climate evolution of the Iberian Peninsula, using these types of growing areas for viticulture represents a sustainable strategy. Their altitude and edaphic properties may help address challenges associated with climate change, such as rising temperatures and water scarcity, thereby promoting more resilient and sustainable agriculture.

References

Espejo, R. (1987). The soils and ages of the “raña” surface related to the Villuercas and Altamira mountain ranges (Western Spain). Catena 14, 399-418. https://doi.org/10.1016/0341-8162(87)90012-9

Martín-Serrano, A. (1991). La definición y el encajamiento de la red fluvial actual sobre el macizo hespércio en el marco de su geodinámica alpina. Revista Sociedad Geológica Españoa, 4, 337-351.

Soil Survey Staff. (2022). Keys of Soil Taxonomy. 13^th edition. Department of Agriculture Unites States.