Fig. 6. Effect of organic amendments on dimethylselenide emissions from packed soil columns. The top 5 cm of soil in column was amended with 1% (dry wt. basis) of either gluten or casein. The soil columns were packed to a final bulk density of 1.65 g cm-3 with Arlington sandy loam and incubated at room temperature. Soil moisture content = 30% maximum water holding capacity (WHCmax).