🪨 Soil drainage
Also known as: soil drainage, vineyard drainage, drainage in vineyards, well-drained soil, soil water-holding capacity
How well soil lets excess water drain down instead of standing in puddles; it decides how much water and air vine roots get.
Soil drainage (how well a vineyard soil sheds extra water) is the ability of the ground to let surplus water move down instead of lying in puddles. For a vineyard it is one of the key properties: standing water starves roots of oxygen, and the vine suffers.
Soil water lives in pores. A 2018 OENO One review explains that water drains out of the large pores, those wider than 10 micrometres. Pores of 0.2 to 10 micrometres hold it and release it slowly to the vine. They make up about 5 % of the volume in very sandy soil, 10 % in clay and 20 % in silt.
That is why the water reserve varies so much: from 50 millimetres in a shallow sandy soil full of stones to over 350 in a deep silty one where roots go far down. Fast drainage is neither good nor bad. In a rainy region a soil with a small reserve keeps vines from sitting wet, while in a dry climate a vineyard needs at least a medium reserve. White varieties generally do better with a big reserve than red ones.
University of California Cooperative Extension describes the ideal as deep, well-drained soil with moderate fertility and moderate water-holding capacity. It advises planting on or near the highest point of a site, where both water and air drain better. Drainage tiles are only a partial fix, since they carry off water from large pores and do little in soils that store it in small ones.
Compare sandy soil, with the smallest reserve, and silty soil, with the largest. Examples such as gravel or chalky albariza have their own pages, next to volcanic soil and the wider topic of soil.
Facts
| Moisture | Pores of 0.2–10 µm hold water: ~5 % of volume in sandy, 10 % in clayey, 20 % in silty soil 1 |
|---|---|
| House range | Soil water reserve in vineyards: from 50 mm to over 350 mm 1 |
| Main use | Carry off surplus water so roots get oxygen; the ideal is deep, well-drained soil 2 |
How it connects to Wine
🪨 Soil drainage ← then ← 🪨 Soil → kind of → 🌿 Terroir → kind of → 🍷 Wine
Links
Frequently asked questions
Where should I plant vines on a sloping site?
On or near the highest point: water and air drain better there, which also helps with spring frost.
Will drainage tiles fix a wet vineyard?
Only in part. Tiles remove water from large pores and have little effect in soils that store a lot of water in small pores.
Is sandy soil good for grapes?
It drains fast and holds the least water, so in a dry climate vines may need help.
Do white and red varieties need the same water reserve?
No. White varieties generally do better with a big reserve than red ones.
Is it true that fast drainage is always an advantage?
No. It is neither good nor bad: in a rainy region a small reserve keeps vines out of the wet, while a dry climate needs at least a medium one.
Similar
🪨 Alluvium · 🪨 Marl · 🪨 Granite · 🪨 Sand · 🪨 Flint (silex) · 🪨 Schist
Sources
- van Leeuwen C., Roby J.-P., de Rességuier L. Soil-related terroir factors: a review. OENO One 52(2), 2018
- University of California Cooperative Extension. Establishing a Vineyard (training presentation)