The study looked at how sulfur dioxide affects the nutrient quality of two types of grass. They found that plants exposed to higher levels of sulfur dioxide had more sulfur in their tissues. The plants with more sulfur also had higher ash content. Protein levels in the grass varied throughout the year, with the highest levels in May and the lowest in August. Grass fumigated with sulfur dioxide for two years had lower protein levels compared to untreated grass. The fiber content of the grass did not change with sulfur dioxide exposure. Grass fumigated for one year was easier to digest compared to grass fumigated for two years.