TRACE-ELEMENT COMPOSITION OF ATRIPLEX GROWN WITH SALINE DRAINAGE WATER

In the western San Joaquin Valley, California, there has recently been emphasis on identifying suitable halophytes for irrigation with agricultural effluent and grown as crops using standard farming practices. Five perennial halophyte species belonging to the genus Atriplex (common name, saltbush) were established with fresh water, irrigated with saline drainage water, and mechanically harvested four times during the first 27 months of growth. Bale samples collected from three regrowth harvests were analysed for Selenium (Se), Boron (B), Sulfur (S), Iron (Fe), Zinc (Zn), Manganese (Mn) and Copper (Cu). The mean tissue concentrations for all species over regrowth harvests were 129 mg kg-1 dry weight for B and 0.6 mg kg-1 dry weight for Se. Tissue levels of B and S were above, and the remaining trace elements were below the maximum tolerable levels recommended for ruminants. All species showed trends of increased tissue B concentrations with cumulative age of plants. Over all the species the highest Se concentrations were measured in forage harvested 27 months after planting. The trace element composition of the harvested forage from this site does not appear to be a limiting factor when considering the use of Atriplex bales as a blend in animal feed rations.