What book did the protagonist in the rural farming novel find? It's about health and self-cultivation. There is an orchard at home. According to the book, the protagonist cooks medicine to drive away insects from trees. It's a wild doctor

The first volume Chapter 5

There is a big pot in the orchard every few meters. The medicine soup in the pot keeps rolling, and the medicine is filled with gas. It smells strange, not the usual medicine. Fruit trees rustle, and usually invisible insects crawl around them.