The other possibility is that nature will force the choice. Not all land is equally useable for all purposes. When nature makes the decision about what land will be farmed and what given over to grazing, it has to do primarily with water and soil conditions. Farmers need the wetter land and access to streams and rivers, the less rocky land, and the less hilly land. A plowed hillside is subject to rapid erosion.
Rocks can break even steel plows.
Without running water, the farmer has both a waste disposal problem and a problem if there should not be enough rain. Cattle herders need somewhat wetter land, but can do with a lot drier land than farmers need. The society depicted in the Hebrew and Christian scriptures is a pastoral society. Most of what Christians call the Old Testament describes the classic herding society and its family, religious, governmental and economic institutions. If you are among that increasingly rare breed of college students who had a couple of years of Latin, you learned a lot about the classic agrarian society in what you learned about Roman civilization while learning the Latin.