Mainer here. The law was proposed by a R state rep in response to peculiar re-zoning strategies playing out in other states that limit what can be grown/raised on private property and commerce/fda regs limiting what can be sold and how between private citizens. It's a way for small producers to get around statutory/regulatory limitations that favor the large agribiz conglomerates whose lobbyists write them.

That said, the wording of the amendment (not law) is vague and will end up only being defined by court cases, meaning an unelected judge will decide what it means. I think the intention of the amendment is good, but the poor execution and imprecise wording will likely mean it has the opposite effect. It will end up being used as a defense for animal abuse and selling contaminated/unsafe food.

Moral: Don't let guys named Billy Bob write amendments