Washington State University scientists in Puyallup, Prosser and Pullman are gearing up to start a comprehensive two-year study of plant uptake of metals for the Washington State Department of Agriculture. The package also included provisions for labeling fertilizer products containing industrial waste byproducts, funding for two studies to be conducted by the state Department of Ecology and, on an interim basis, adopted Canadian standards for maximum annual metal additions to the soil. We will also try to find out what the biotransfer factors are. Biotransfer is the transfer of a substance from a growing medium to living organisms or from one living organism to another. This study will look at the degree to which plants take up heavy metals found in various types of fertilizers.
Fertilizers contain different amounts of heavy metals.
They have different chemistry and react differently with soils. The magnitude and rate at which these heavy metals are released from fertilizers and their subsequent uptake by plants may vary considerably, depending on the type of fertilizers, soil, crop, and environmental conditions. In field studies at Prosser, scientists will try to determine how much metal in fertilizer can be transferred to winter wheat and potatoes following normal and above normal applications of phosphate fertilizers, including rock phosphate and triple superphosphate, and granular zinc. These fertilizers are known to contain elevated concentrations of lead and cadmium. In Puyallup, using rock phosphate, triple superphosphate and ironite, a mine tailing known to contain high levels of arsenic, scientists will perform similar tests with lettuce and cucumber.