Difficulties of Food Production
Food production is difficult to manage. Not only do farmers need large amounts of lands to grow food, but certain foods can only produced once a year. Even worse, there can be several variants of a particular crop which only grow well in certain regions and not all variants produce a large quantity of food.
Other factors can also contribute to food production. For example, certain diseases can ravage crops as well as natural disasters such as famines which can devastate crops in particular seasons. Before the advent of the Green Revolution, human populations were in control due to the limited amount of food available to certain nations. It would take an agricultural movement to change all of this.