Soil Types

	Soil Types of Interest to Viticulturists
Type	Description	Characteristics
Clay	Smallest and heaviest soil particle	Fertile (good water retention and nutrient transfer)
		Colder than looser-textured soils (Slow ripening)
		Higher acid, more tannic wines Red wine grapes benefit from substantial  amount of clay in soil - Particle size allows better nutrient and  water uptake by tiny rootlets - Helps grape skins develop polyphenolic compounds
		Merlot and Chardonnay flourish
Silt	Next largest particle	Accelerated ripening due to hydric stress
		Warmer; reflects more of sun's rays
Loess	Mixture of clay and silt	Found in Germany and Austria
Sand	Largest-sized particle	Most loosely textured soil
		Holds least amount of water
		Too dry to produce high-quality grapes
		Accelerated ripening due to hydric stress
		Warmer; reflects more of sun's rays
Sandstone	Rock composed of bonded sand	Variable in density
		Quality wines if containing feldspar
		(Called Macigno in Chianti Classico) Erosion turns it into sand
Loam	Combination of clay, silt, and sand	Fertile
		Rich in organic matter and nutrients
		Good water retention
		Vigorous, thus lowering quality
Gravel	Composed of quartz	Drains freely
		Excellent heat retention
		Useful for late ripeners like Cabernet
Limestone	Composed of marine fossils	High in calcium (Gives wine good structure) Can block root development
Albarese	Hardened marlstone that approximates limestone	High calcium carbonate content White or pastel
Calcareous	Soil with chunks of limestone
Marl	Crumbly mixture of limestone and clay
Chalk	Special type of limestone	Soft enough for roots to penetrate
		Cool
		Almost perfect water delivery
		Alkaline soil leads to high-acidity wines
		Low-vigor environment
Granite	Igneous rock formed in earth's core	Loosely textured soil when weathered
		Drains well
		Low fertility
		Gamay and Syrah thrive here
Schist	Igneous rock formed in earth's core	Loosely textured soil when weathered
		Drains well
		Low fertility
		Gamay and Syrah thrive here
		Crystaline structure splits easily into layers
		Fruit, floral mineral aromas
Galestro	Highly friable clay schist (better described as shale)
Shale	Layered, hardened clay
Slate	Shale subjected to heat and pressure	Good heat and moisture retention
Volcanic	Lava, pumice, tufa from volcanoes
Macigno	Rock composed of bonded sand	Has a low calcium carbonate content Usually dark gray, brown, or reddish-brown
Source: Compiled from education.mhusa.com Click here to see my post on the influence of soils on vine plant growth. Click here to see my post on soils and vineyard site selection. Click here to see my post on the soils of the Carso and Douro regions. Click here to see my post on Kimmeridgian soil Click here to see my post on the soils of Champagne Click here to see my post on the soils of the Beaujolais and Douro regions Click here to see my post on the soils of Burgundy Click here to see my post on the soils of the Loire Valley Click here to see my post on the Rhone Valley soils Click here to see my post on the soils of the Northern Rhone Click here to see my post on the soils of Limoux AOC Click here to see my post on the soils of Tavel AOC Click here to see my post on the soils of Sicily Click here to see my post on the soils of Mt Etna Click here to see my post on the soils of Umbria and Orvieto