I am designing a fictional world (no magic, real-world technologies). I have an unexplained anomaly in my world: There is a natural "bold spot" in the jungle (in the thousands of square kilometers), at a latitude of 9°S. The land is very fertile, hence there is intense agriculture.
The technology level is of the 1930's, with requirement for manual labor. My issue is that the number of farm hands per hectare varies widely across the real world. The real world number ranges from 5 to 0.01 workers per hectare in today's times. [I can't find that reference online]
I picked the number of 0.8 workers / ha. (Imagine approximately 2 football fields of crops, with a single permanent worker responsible for it). My farm sizes vary from 200ha to 4000ha. In my initial design, I neglected to "house" these workers. Now, I'm retrofitting the design with farm worker villages. I group the labor from 2 to 5 of these farms into a "village". (Transporting the crop from these farms to the market / storage is an issue, but is beyond the scope of this question)
The issue is, that these villages are of substantial size: On average, they have a population of 7,000. This population also includes services like schools, governance, religion, basic shopping, doctors, entertainment (theaters and libraries). Land is also provided for a cemetery, and a waste water treatment plant. Villages provide no industry or commercial offices. These "villages" are build to urban standards, with each farm worker household having a free-standing house (400m² plot). The villages are usually within 200m to 2km of the farm house. The villages are approximately 250ha in area.
Additional services (like industry, crop storage, transportation hub, commercial offices, higher education) are provided by the anchor town, usual population is about 40,000 inhabitants.
The question is, is my number of 0.8 workers per hectare (100m x 100m) realistic? The issue is that a 1017km² county holds a population of 267,480. That gives me a population density of roughly the UK. http://statisticstimes.com/population/countries-by-population-density.php With about 28 to 30 of these Counties, I'll have an agricultural population in the millions. The grand plan for the map is to iterate through time (5 years at a time) until the year 2020. I will be installing highways and other modern infrastructure when the time is right. Bonus question: As I iterate through the decades, what do I need to look out for?