Mass balances and allocation of salt ions from Solvay storm water for shrub willow (Salix spp.)

Storm water containing high levels of chloride was collected from the Solvay wastebeds to irrigate willow varieties Salix miyabeana (SX64), S. purpurea (9882-34), and S. sachalinensis × S. miyabeana (9870-40) that were grown in organically-amended Solvay waste. During a greenhouse study five storm water treatments containing 163, 325, 813, 1625 and 8125 mg Cl− L−1 and a tap water control were applied. All willows used in this experiment resulted in the accumulation of 62%–95% of Na+ and Cl− in the plant/soil system, but less than 0.5% of this was being stored in plant tissues. The results also indicated that electrical conductivity measurements above 6 mS cm−1 may be a good stress predictor. For all varieties most Na+ was allocated to the roots and most Cl− to the leaves. The balanced Na+/K+ and Na+/Ca2+ ratios in the shoots of all shrub willow varieties indicated that they were able to tolerate storm water treatments with 1625 mg Cl− L−1 and 405 mg Na+ L−1 for up to 10 weeks.

► Highly saline storm water was used to irrigate three willow varieties.
► Willows accumulated significant amounts of Na+ and Cl− in plant/soil system.
► Electrical conductivity may be a good predictor of salt stress in woody crops.
► Willows can tolerate short term treatments of 1625 mg Cl− L−1 and 405 mg Na+ L−1.