The tech levels 1 through 4 are pretty much the same from the farming perspective:
TECHNOLOGICAL LEVELS
Digit Description
1 = Bronze Age to Middle Ages
2 = circa 1400 to 1700
3 = circa 1700 to 1860
4 = circa 1860 to 1900
As far as the farmer was concerned farming was back breaking labor with the assistance of farm animals, most of the technological improvements were in the field of warfare. If you were raising chickens of planting crops, it didn't make much difference to you whether the soldiers of the time were swinging swords, firing muskets, rifles, or Gatling Guns, farming was pretty much the same and unmechanized, people mostly traveled on foot or on a horse, that didn't change much until tech level 5 was reached. In tech level 4 you had steam trains, but you still had to walk to the station to get on one, the invention of the telegraph and telephone did allow for faster communication, but you still had to stand behind you plow horse to till the fields. Farming was pretty safe up until 1900, and even at tech level 5 plenty of people still farmed the old fashioned way, horses and cars coexisted on the roads for a few decades in the early 20th century, at tech level 6 people started living in suburbs and started making use of the automobile to commute to work, better transportation allowed for the creation of larger more automated farms and thus fewer farmers. I think by the time tech level 6 is reached you start having upheavals, and the Romand did love road building.
I think you can have advancement in tech levels up to 5 without major disruptions in the way people earn a living, which was that of yeoman farming, the single family farm where people grow their own food, and use their surpluses in crop production to trade for stuff they cannot make themselves. In tech levels 1 through 4 the Roman peasant is going to be growing his own food, riding on a horse or walking on his own two feet, not much changes for him unless he is going to be doing military service.