Influence of soil properties on grape and must quality in the MontillaMoriles protected designation of origin (southern Spain)

There is a growing interest among consumers in some world regions in high-quality products including wine. In this work, we examined the unique quality wines obtained in the Montilla - Moriles wine Protected Designation of Origin (PDO) (C<acute accent>ordoba, southern Spain). Specifically, we assessed the influence of soil properties on the production and quality of Pedro Xime<acute accent>nez grapes in the Montilla - Moriles PDO terroir in six vineyards typical of three different production areas, namely: Sierra de Montilla and Moriles Altos (two premium-grade areas), on soils known as "albariza", characterized by their parent material (mainly marls and limestones), with a high calcium carbonate content and low organic matter content; and one standard-grade area (Ruedos), with soils developed on varied materials including Miocene marls, which are steeply and highly eroded. Representative soil profiles were evaluated and a field experiment to conducted to obtain data on grape production and quality over a period of three years in the six vineyards. Wine quality in the premium-grade areas was strongly influenced by physical characteristics of the vineyards (altitude and age), and also by some soil properties (limestone, poorly crystalline Fe oxides, and available P, Zn and Cu), production-related characteristics (leaf surface area exposed to solar radiation) and oenological variables (tartaric acid content). By contrast, quality in the standard-grade area was more closely related to soil sand and available Mn, and also to scarcely available P and Zn; however, grape bunches were more abundant and grapes larger (100-berry weight) in this area, and the must produced was richer in malic acid. These results suggest that soil properties in each premium-grade area of the Montilla-Moriles PDO (viz., Sierra de Montilla and Moriles Altos) set them apart from each other and distinguish them from the standard-grade area (Ruedos). Such soil properties are associated to consumer-appreciated quality-related parameters.