Soil Science Simplified by Neal Eash and others, and Landrace Gardening by Joseph Lofthouse.

Soil Science Simplified is a bit textbook-y but it's easy to understand, and it's about soil in the context of, well, anything that could be used on or in the soil, such as in agriculture and building infrastructure. I'm not that far into it but if you remember clay, sand, silt and loam soil from Elementary, then it goes into much more, such as how the soil made out of certain minerals can behave like.

Landrace Gardening is a lighter read for me, and I'm honestly just reading it to feel persuaded to grow healthy plants. It does feel like the author is hammering his points into you, but there are some useful information here and there. Then I'm proceeding to Principles of Cultivar Development by Walter Fehr.

Why am I reading these? I got interested in preserving Siling Labuyo, a local cultivar of hot chili in the Philippines, which is gradually being overshadowed by Thai Bird's Eye... Most people in my country don't know what Labuyo really looks like nowadays, despite being popular in the past... the bird gods have randomly given us labuyo some time ago, and since labuyo has usually been grown wild, it has quite a high genetic diversity. I'm thinking of cultivating it. Maybe make a super labuyo and make it get popular by attaining the title of hottest chili again. But that's obviously a pipe dream, lol. Anyway this is what ADHD does to you /shrug