Agriculture (Civ4)/Civilopedia

Agriculture is the science of cultivating soil, planting and harvesting crops. It can be argued that the mastery of agriculture was the single most important step towards creating a civilization, as agriculture allowed people to stop hunting and gathering and settle down in one place. Villages and cities would be unviable without some form of agriculture.
Evidence of plant cultivation dates back as far as 6000 BC. Apparently, grains were some of the earliest crops cultivated. Grains are incredibly useful foodstuffs; they can be ground into flour and turned into bread, they can be fed to livestock and, perhaps most importantly, they can be stored for months without spoiling.
Over time a number of important tools were invented to aid in cultivation and preparation of grains. The sickle was an early innovation. It allowed the grain to be harvested far quicker than by hand. Hand mills and mortar and pestles were created to grind the finished product, and pots to store it. As man learned about fertilization and irrigation, it became possible to get consistently larger yields, which lessened the chances of famine and increased the numbers that could be fed from each field.