If you want to know something about agriculture read Marcus Terentius
Varro, De Re Rustica and Lucius Iunius Moderatus
Columella. There are also fragments of Marcus Porcius
Cato, De agri cultura. There is some literature as well. In English e.g. you can read Tilly, B., Varro the Farmer, 1971 - Skydsgaard, J.E., Varro the Scholar - White, K.D., Roman Agricultural Writers I, in: Aufstieg und Niedegang der rmischen Welt (ANRW), 1,4, 1973, pages 439-497. In Italian: Noe, E, L'agronomo Tremellio Scrofa, NAC 6, 1977 or in German: Cichorius, C., Historische Studien zu Varro, in: Rmische Studie, 1922 - Flach, D., Marcus Terentius Varro, in: Texte zur Forschung, 65, 1996.
I would prefer Flach, but I don't know if you can understand German.