In let’s say 1520, Tenochtitlán had a huge population, upwards of 200,000. I’ve read about the incredibly fertile chinampa farming strategy, with floating/irrigated polyculture gardens that produced several harvests a year.
I see maps that show the area immediately surrounding the city to be predominantly chinampas, but were they also integrated throughout the city, as parks are in modern cities?
There also appear to be various farms in other parts of the lake. Could Tenochtitlán support its population with only what was grown immediately around it, or would it need to import food from further out in the lake? Or was even that not enough, meaning the massive population was dependent on farms throughout the empire?
And perhaps most hypothetically: what area of chinampas was required to support a city-dweller on average?
I believe u/400-rabbits made a pretty extensive response on the subject.
The only things that I think can be added to his response are the facts that the chinampas complemented other forms of resource exploitation in the Valley, Aztecs were also knows to fish extensively throughout the Valley owning to the fact that it is a salt lake and that it was heavily developed including extensive waterworks and infrastructure and also that they had an extensive tradition of poultry farming, with turkey being a particular stand out.
The other important factor that I think can be added is the importance of the basic social organizational unit that the Aztecs used, the calpulli, roughly speaking the calpulli represented the population of a borough, however, Aztec property worked in a communitary fashion, meaning that the land itself technically was property of the many calpullis that existed (with the tlatoani and myriad nobles owning perhaps some 10% of the land directly), this means that most of the resource exploitation and production was formed around the many calpullis that existed.
Now, individual private property within the calpulli was assumed when an individual (or rather a nuclear family, as families were more important in Aztec society) worked the land, this giving practical property of that land to the family or individual, even though the calpulli as a whole kept the theoretical property of the land.
We know from works such as Sahagun's Historia General de las Cosas de la Nueva España that many if not most families in Tenochtitlan kept their own small farms (huertos) within their properties where they grew a myriad of crops (hortalizas) both common like maize or specialized like tomatoes for example, most sources also agree that many people kept domesticated animals for consumption like turkey (or dogs in some cases). Many families used this family farms to grow food both for self-consumption and to sell the excess production in the markets.
On top of this there was a well documented system of taxes (both in produce and labor) that the empire used to keep the flow of goods and produce into the city, which depending on whether the actual population of Tenochtitlan, its twin city of Tlatelolco and outlying settlements is on the lower ends of 200k or the higher ends of 500k might have been necessary or even critical to the food consumption of the city.
TL;DR: There was a variety of resource exploitation within and around the city, there are wide estimates for population in the city (200k-500k) that are available, but at the lower ends the city might've been self-sustaining yet probably needed the commerce and excess produce the empire brought to comfortably sustain the growing population.
