“…Common inorganic species include soluble selenate (Se(VI)), selenite (Se(IV)), insoluble elemental selenium (Se(O)), and various metal and organic selenides (Elrashidi et al, 1987;Masscheleyn et al, 1990). Selenite, which is stable under moderately reducing conditions, is soluble, but can strongly adsorb onto surfaces of common soil minerals and organic matter (Geering et al, 1968;Hingston et al, 1971;Hamdy et al, 1977;Balistrieri and Chao, 1987;Bar-Yosef and Meek, 1987;Neal et al, 1987;Christensen et al, 1989). Organo-selenium species include seleno-amino acids and volatile methylated Se compounds (Reamer and Zoller, 1980;Zieve and Peterson, 1981 ;Doran, 1982;Thompson-Eagle and Frankenberger, 1989).…”