Grapevine nutritional status and K concentration of must under future expected climatic conditions texturally different soils

Nutrition is a relevant issue for winegrowers because it influences grapevine growth, berry composition, as well as must and wine quality. In this research, the following impacts on the nutritional status of cv. Tempranillo grapevines were evaluated: simulated 2100 expected CO2, temperature (T) and relative humidity (RH) conditions (FCC; 700 μmol CO2/mol air, 28/18°C day/night and 33/53% RH, day/night) vs. current CO2, T and RH conditions (Curr; 390 μmol CO2/mol air, 24/14°C and 45/65% RH); well-watered (WW) vs. future expected water deficit (WD); and three texturally different soils with different clay contents (41, 19 and 8%). FCC resulted in reduced concentrations in leaf blades of N and Ca at veraison and N and Zn at full maturity. WD resulted in higher leaf blade Na and Mn concentrations at veraison and maturity, respectively compared to WW. However, K concentrations in the leaves and must were higher for WW than WD. Higher concentrations of Ca and Mn were found in leaf blades of grapevines sampled at full maturity from more clayey soils. Even when nutrient inputs exceeded plant extractions, high soil clay content increased the K concentration in must and consequently, could affect wine quality in terms of acidity loss. However, future expected water stress will have the opposite effect, reducing the berry K uptake under high soil clay (41%) conditions.