Vineyard soil mapping to optimise wine quality: from ‘terroir’ characterisation to vineyard management

In this study, a soil mapping methodology at subplot level (scale 1:5000) for vineyard soils was developed. The aim of this mapping method was to establish mapping units, which could be used as basic units for ‘terroir’ characterisation and vineyard management (precision viticulture). The developed methodology applied most of the criteria of the Soil Inventory of Catalonia and the Soil Survey Manual of the Department of Agriculture of United States, at very-detailed scale. The suitability of soil maps as a tool for definition of ‘terroir’ units and management units are discussed, according to our experiences. The method followed allowed good soil type discrimination at vineyard subplot level, differentiating zones with distinct soil properties important to vineyard development. However, the variability within the soil mapping unit could not be ascertained by this method. Significant differences in grape quality were found between distinct soil mapping units. Moreover, the application of variable rates of fertilizer at vine subplot level was possible using thematic maps calculated from soil maps, by means of Geographic Information Systems.