Using saline reclaimed water on almond grown in Mediterranean conditions: Deficit irrigation strategies and salinity effects

The main objective of this study was to acquire agronomic knowledge about the effects of irrigation with saline reclaimed (RW) and desalinated DESERT (DW) water and different irrigation strategies: control full irrigation (FI) and regulated deficit irrigation (RDI) on leaf nutrients, tree growth and fruit quality and yield of almond trees in pots. Our results showed that RW had the highest concentration of some valuable agronomic nutrients such as N, but also of phytotoxic elements (Na and Cl). Na leaf concentration on RW treatments reached toxic levels, especially under RDI, and toxicity symptoms were shown. Regarding tree growth, cumulate trunk diameter on RW-RDI was significantly lower than on the control treatment and shoot growth was reduced from the beginning of the irrigation season in RW treatments. Maximum yield was reached on RW-FI, 18% higher than the control treatment. However, RDI strategies influenced negatively on yield, being 23% less in RW and 7% less in DW although water productivity was not significantly reduced by water stress. These findings manifest that the combination of RW and RDI can be a promising future practice for almond irrigation, but long-term studies to establish suitable management practices must be developed.