Vines are extremely robust and can grow and flourish even in the most inhospitable of climates and terrains. Many factors influence the growth of the vine and grapes, such as the site of the vineyard, the weather, the soil and even the method of pruning.
Vines will grow well in most soils providing their roots are able to dig deep into the soil, so that during dry spells they are able to find the moisture they need to grow and support fruit. The best soils are loam soils, or soils which are 'crumbly', since they allow the expansion and aeration of the plant's roots. Abundant stones and pebbles are often found in the soils of the most successful vine growing areas, as they help to aerate the soil.
Almost as important as moisture to the growth of strong and healthy vines is the mineral composition of the soil. Too much nitrogen and organic matter can result in abundant but low quality harvests, and excess quantities of iron can produce wines that oxidise. Where too little iron is present, or where the soil has too high a lime content, chlorosis will prevent the vine from thriving. On the other hand, phosphorous and potassium have an extremely positive effect on the quality of the grape, as does calcium in the form of chalk, limestone, gypsum or marl - in fact many of the great red wines, such as Vega Sicilia, come from calcium rich vineyards.
Many Spanish wine producers claim that the grapes produced in their regions have unique characteristics and qualities, influenced by the special mix of climate, soil, etc in their locale, despite the fact that the vines appear to be of the same variety. The best example of this is the Tempranillo grape, the main grape grown in Spain. Some believe that the Tempranillo grape may in fact be the Burgundian Pinot Noir, which was transplanted to Spain many centuries ago and has since developed its own 'Spanish', and even 'regional Spanish' characteristics as a result of the influence of the local climate and soil. For example, the Tempranillo grape grows thicker skins in hotter regions of Spain, and it is this ability to adapt that has caused much debate amongst some experts as to whether this should now be classed as the same vine. Consequently, Tempranillo is known within Ribera del Duero as Tinto del País, and Tinta de Toro in the Toro region.
Given all these local soil and climatic influences it will come as no surprise that the wines produced from the Tempranillo, and other grape varieties grown in Spain, vary significantly from region to region and even vineyard to vineyard. The result is some extremely interesting and varied wines.
Our only problem is that we are now spoilt for choice!