The study looked at how adding different types of lime to soil affects the growth of rooibos tea plants over four years in Clanwilliam. They found that micro-fine lime raised the soil pH more than class A lime, but both types caused the pH to drop after two years. Despite improving some nutrients in the plants, adding lime actually decreased the tea yields. This suggests that adding lime to the soil in Clanwilliam may not be helpful for growing rooibos tea.