Short answers, pulled from the story.
The word cereal derives from Ceres, the Roman goddess of grain crops and fertility. This linguistic lineage traces back to the Neolithic period, approximately 8,000 years ago, when humans first began to domesticate wild grasses in the Fertile Crescent.
The Green Revolution occurred during the second half of the 20th century and introduced mechanized tilling, monoculture, and nitrogen fertilizers to increase yield-per-plant. This movement successfully raised overall yields of cereal grains like wheat and rice but resulted in low-quality proteins and environmental degradation including soil erosion and water table lowering.
Cereals are grasses in the Poaceae family that produce edible grains known botanically as caryopsis. Among the best-known cereals are maize, rice, wheat, barley, sorghum, millet, oat, rye, and triticale, while pseudocereals include buckwheat, quinoa, and amaranth.
In mechanized agricultural systems, harvesting is done by combine harvester which cuts stalks and threshes grain in a single pass. Traditional agricultural systems in the Global South often use hand tools such as scythes and grain cradles to harvest the grain.
The Americas and Europe are the largest exporters of cereals while Asia is the largest importer. The US is the largest exporter of maize, India is the largest exporter of rice, and China is the largest importer of both maize and rice.
As whole grains, cereals provide carbohydrates, polyunsaturated fats, protein, vitamins, and minerals. When processed by the removal of the bran and germ, all that remains is the starchy endosperm, which is less nutritious but more shelf-stable.