Feasibility of Irrigating Pickleweed (<i>Salicornia bigelovii</i>Torr) with Hyper‐saline Drainage Water

<jats:p>Reuse of drainage water (DW) for irrigation reduces the volume of DW requiring treatment or disposal. We conducted a greenhouse study to evaluate the performance of the halophyte<jats:italic>Salicornia bigelovii</jats:italic>Torr. when irrigated with hyper‐saline DW and seawater (SW) treatments, ranging from 1/3 strength to full strength (18–49 dS m<jats:sup>−1</jats:sup>), in a sand‐culture system. Results indicate that<jats:italic>Salicornia</jats:italic>grows well over the entire range of iso‐osmotic SW and DW salinity treatments. Moreover, when boron (B) was added to SW treatments to concentrations equivalent to that of corresponding 1/3‐ and 2/3‐strength DW treatments (i.e., 9 and 17 mg L<jats:sup>−1</jats:sup>), growth was not affected, and tissue B concentrations were <150 mg kg<jats:sup>−1</jats:sup>dry wt. However, when plants were irrigated with synthetic DW where B was reduced to solution culture levels (0.5–1.0 mg L<jats:sup>−1</jats:sup>), plants generally performed worse than when irrigated with actual DW high in B at the same salinity level. Evapotranspiration (ET) rates exceeded that lost from an evaporation pan from 1.5 to 2.5 times. Using a method accounting for changes in the isotopic signature of water in the reservoir due to evaporation, we estimated that high ET rates were due primarily to high transpiration rates (>78% of ET). The salt content in the tissue was very high (ash content 43–52%), but ionic composition in the shoot tissue reflected that of the treatment water used to irrigate the plants. These data indicate that hyper‐saline DW, characteristic of California's San Joaquin Valley, can be used to irrigate<jats:italic>Salicornia</jats:italic>and substantially reduce drainage volumes.</jats:p>