COMPETITIONS FOR NITROGEN AND WATER IN TWO VINE-GRASS SYSTEMS – APPLICATION OF A WATER BALANCE MODEL

In view of the growing interest in vineyard cover crops, a study was conducted to analyse competition for nitrogen and water and how it differs with regard to soil conditions.
Grassed and non-grassed vineyards (Saumur area, Val de Loire, France) were compared in two distinct soils by periodically measuring nitrogen and water contents in the soil and vine leaves during the 1997 growing season.
TDR and leaf water potential techniques were used.
Water uptake by the vines and the grass, evaporation from the non-grassed soil surface, and (positive or negative) drainage were all estimated by fitting a water balance model to the data.
Results show that nitrogen was strongly taken up by the grass early in the growing season, but vines did not suffer from such competition for water.
That was caused by root system adjustment, which also changed significantly according to soil characteristics.
These results may lead to improvements in the management of vineyard cover crops.

I ISHS Workshop on Water Relations of Grapevines

P. Pieri, C. Riou, C. Dubois

Vitis vinifera, Festuca, nitrogen uptake, water balance, soil water depletion

https://doi.org/10.17660/ActaHortic.1999.493.8