When the Romans were cultivating vines in Germania, the crops were grown on trellises, frames or posts, similar to current cultivation methods. What is less well known is that the Romans grew their vines directly beside trees. The trees therefore served as a type of espalier for the vines, allowing them to quickly reach the top of the trees and reach the light. Trees and vines competed for space and therefore for light in this method of cultivation, and were also competing below ground for nutrients from the earth and for water.
What effect this mutual cultivation of trees and vines had is unknown. The Arbustum Project in Ayl should answer these questions. It came about as a result of cooperation between the University of Freiburg, the community of Ayl and local Saar winegrowers.
In autumn 2005, 850 vines were planted over an area of 1 hectare (half each of Riesling and Sauvignon Blanc) in accordance with a sophisticated planting scheme. In December 480 trees (half each of sessile oak and poplar) were added. With oak and poplar, a slow-growing type of tree with a wide spectrum of tolerance in respect of water supply (oak) can be compared with a comparatively fast-growing type of tree with a high demand for water (poplar).
The system also got its name from the trees, as the Latin "Arbustum" means "planted with trees" in the language of the Romans. In terms of vines, the scheme used a typical regional Riesling, which is the main type of grape grown on the steep shale hillsides of the Saar, as well as a Sauvignon Blanc, which has attracted increasing interest in recent years from German winegrowers.