Application of nitrogen forms such as nitrate, urea, and amino acids effects on leaf and berry physiology and wine quality

Several factors like vineyard site, climate, grape variety, ripeness, physical health of the grapes and pest management influence the populations of indigenous yeasts on grapes and later on in spontaneous fermentations.

The choice of sites for viticulture depends on natural environmental factors, particularly climate, as grapevines have specific climatic requirements for optimum physiological performance and berry quality achievement. In the Stellenbosch wine-producing region, the complex topography and the proximity of the ocean create a variety of topoclimates resulting in different growth conditions for vines within short distances.

The “Anjou Terroirs” programme aims at bringing the necessary scientific basis for a ratio­nal and reasoned exploitation of the technical itinerary of the terroir. The scale study is 1/12500. For the mapping, many parameters, such as the granulometry or the depth of soil are observed to each point of caracterisation.

The impact of viticulture on soil can be determined by comparing the biophysical properties that represent soil health at a particular site and depth with those same properties in soil considered to represent the ‘pre-vineyard’ state (the headland). Information gathered by this method shows the changes in soil properties following the change to viticulture depend on individual vineyard management and environment.

The mechanical strength or firmness of a fruit is considered an important parameter to characterize its state of maturity or conservation, as other parameters such as sugar level or color.