Effects of water stress on selenium accumulation in tall fescue (Festuca arundinacea Schreb) from a selenium-contaminated soil.

A greenhouse experiment was conducted evaluating the effects of water stress on uptake and accumulation of selenium (Se) as well as on uptake of calcium (Ca), potassium (K), and magnesium (Mg) in tall fescue (Festuca arundinacea Schreb). Also, this study has documented changes in soil Se inventory of Se-contaminated field soil. The findings of this experiment suggest that low soil moisture and plant water stress had a positive effect on plant tissue Se concentration. However, the negative effect of water stress on plant growth superimposed the increase of plant tissue Se concentration. Therefore, Se accumulation and soil Se removal by tall fescue became largely dependent on plant dry weight production. Strategies utilizing for remediation of Se-contaminated soils should maximizing the growth rates of tall fescue by maintaining soil moisture levels above water-stress conditions (greater than -1.0 MPa). The results of this study also suggest that the relative sensitivity of net uptake of Se and the three macronutrients to reduced soil moisture is: Ca uptake < Se uptake < Mg uptake < K uptake.