The scientists mixed garden waste and spent mushroom compost in different ratios to see which combination worked best for vermicomposting. They used earthworms to help break down the materials. The mix with 50% garden waste and 50% spent mushroom compost had the highest earthworm growth and reproduction. This mix also had the highest increase in nutrients like potassium, copper, and zinc in the compost. When more than 50% spent mushroom compost was used, the compost had high electrical conductivity, which limited earthworm cocoon growth. Overall, the 50/50 mix was the best for making high-quality compost for plants that don't need a lot of nutrients, or the compost could be rinsed with water to lower the electrical conductivity.