The answer to this question is a bit tricky to answer, as there are many factors that contribute to it. If the question is referring to large populations like that of the world today, the answer is a shaky yes. Our current level of agriculture isn’t a sustainable one and only time will tell if the world’s population continues to grow, caps off, or even drops due to modern farming practices. To begin, some factors need to be considered. How much land is available? What sort of climate does the population live in? Is the climate stable? Does one population have more resources than another? Does the population eat meat? A quick glance at history can provide some insight.
Before agriculture humans lived in hunting and gathering societies; small bands that could only sustain a tiny, extended family group. It wasn’t until humans settled that in the Fertile Crescent that populations began to increase. Cities like Uruk and Ur had populations in the hundreds of thousands. They were sustainable, of course, but were still at the mercy of the climate. The climate of the area was stable for the most part, but the Tigris and Euphrates were prone to occasional flooding. This, naturally, meant that some people would go hungry or starve. In addition, the area was also constantly at war with it’s neighbors.
War consumes resources at a frantic pace. And a common tactic in war (even today) is to destroy the enemy’s source of food. This may have happened thousands of years ago, but these examples are still applicable today.
Much of our farming now is a result of the Green Revolution – picking certain traits of a fruit or vegetable and encouraging that specific trait to grow and be cultivated. With this also came the widespread use of pesticides. However, with the current cultural shift towards organic and natural foods, we would see less available products. This would only happen IF all food was organic or natural. These kinds of foods are more expensive. Less available and more expensive food means more people going with less or none at all. Without proper nutrition, populations become sick and eventually die off.
Another big question to ask is whether or not the population is carnivorous. In our modern day society we see a shift towards meat substitutes. The reason for this is an overconsumption of animal products. Hunting on a small scale allows for an animal population to regenerate, but large scale animal farming and industrial livestock production consumes literal tons of plant and water resources. Crops are grown for the sole purpose of being fed to animals. This takes up millions of acres of land; land that could otherwise be used to grow crops for direct consumption. If a population does not consume meat, ther0eteically, it could hold a larger number of inhabitants as precious resources aren’t used to feed livestock. Meat still could be consumed, but on a MUCH smaller scale.
While there are many moving parts and several variables that go into whether or not a large population could survive on mere agricultural farming, the answer is yes. However, many factors need to be considered and there isn’t a definite yes or no answer to it.