Researchers tested using leftover mushroom material (spent mushroom substrate) as a growing medium for milky mushrooms instead of traditional loamy soil. While traditional soil produced more mushrooms overall, the mushrooms grown in the recycled substrate contained significantly higher levels of beneficial minerals like zinc, copper, and phosphorus. The study found that beneficial bacteria in the recycled material helped make nutrients more available to the mushrooms, making this approach both environmentally friendly and nutritionally advantageous.