Effects of controlled levels of sulphur dioxide on the nutrient quality of western wheatgrass.
A native grassland in SE Montana dominated by Agropyron smithii was continuously fumigated with 2, 4 or 7 p.p.h.m. SO2 from mid-May until Oct. 1975 and from April until Oct. 1976. Fumigation with SO2 increased the S and ash content of A. smithii. CP content was significantly reduced by 2 yr of SO2 treatment. DM digestibility was significantly lower after 2 yr of SO2 treatment.