The effect of recycled water on the nutrient status of Soultanina grapevines grafted on different rootstocks

The effects of municipal reclaimed effluent on the nutrient status of potted Soultanina grapevines grafted on three rootstocks (41B, 1103P and 110R) and irrigated at various fractions of evapotranspiration (0.50, 0.75 and 1.00) were investigated for a 3-year period. Vines irrigated with recycled water had a lower leaf-N content, which reached deficient levels early in the 1999 season. With regard to the other nutrients (P3+, K+, Mg2+ and Fe3+), the findings in this study show that effluent was capable of supplying vines with sufficient quantities of all of them. Enhanced levels of Zn2+ and Cu2+ were also found in the leaves of vines irrigated with recycled water, but their content remained within the acceptable range suggested for grapevines. The irrigation level strongly affected leaf-K+ status, but only minor effects were found for the other elements. Rootstock had a major effect on leaf nutrient content. Significant interactions between rootstock and water quality reveal that the effect of rootstock on vine nutrient status was also affected by the availability of nutrients. Vines grafted on 41B showed a greater capacity to maintain leaf nutrient content, irrespective of nutrient availability, than those grafted on 1103P and 110R.