The Sacred Tree of the Elves Is in My Backyard

A fantasy world of swords and magic, but magic is gradually dying and civilization is at a medieval level. It is rich in natural resources, but its farming technology and living standards are relatively backward. There are many races such as humans, elves, orcs, and dwarves, and there are barriers and even conflicts between them. The protagonist uses scientific thinking to deconstruct agricultural problems in the magical world, uses hybrid rice to overturn magical wheat fields, and uses pesticides to teach demonic pests how to behave. Farming is not only about survival, but also a core event that revives mysterious ancient trees and connects different races.