History of agriculture
Wild grains were collected and eaten from at least 20,000 BC. From around 9500 BC, the eight Neolithic founder crops – emmer wheat, einkorn wheat, hulled barley, peas, lentils, bitter vetch, chick peas, and flax – were cultivated in the Levant. Rye may have been cultivated earlier but this remains controversial. Rice was domesticated in China by 6200 BC with earliest known cultivation from 5700 BC, followed by mung, soy and azuki beans. Pigs were domesticated in Mesopotamia around 11,000 BC, followed by sheep between 11,000 BC and 9000 BC. Cattle were domesticated from the wild aurochs in the areas of modern Turkey and Pakistan around 8500 BC. Sugarcane and some root vegetables were domesticated in New Guinea around 7000 BC. Sorghum was domesticated in the Sahel region of Africa by 5000 BC. In the Andes of South America, the potato was domesticated between 8000 BC and 5000 BC, along with beans, coca, llamas, alpacas, and guinea pigs. Bananas were cultivated and hybridized in the same period in Papua New Guinea. In Mesoamerica, wild teosinte was domesticated to maize by 4000 BC. Cotton was domesticated in Peru by 3600 BC. Camels were domesticated late, perhaps around 3000 BC.
Agriculture in Scotland
Mesolithic hunter-gatherer encampments formed the first known settlements in Scotland around 8500 BCE. These were highly mobile boat-using people making tools from bone, stone and antlers. In the Neolithic period, around 6,000 years ago, there is evidence of permanent settlements and farming. Archaeological evidence indicates that the two main sources of food were grain and cow's milk. From the beginning of the Bronze Age, about 2000 BCE, arable land spread at the expense of forest. From the Iron Age, beginning in the seventh century BCE, there is evidence of hill forts in southern Scotland that are associated with cultivation ridges and terraces. Souterrains, small underground constructions, may have been for storing perishable agricultural products. Aerial photography reveals extensive prehistoric field systems that underlie existing boundaries in some Lowland areas, suggesting that the fertile plains were already densely exploited for agriculture. During the period of Roman occupation there was re-growth of birch, oak and hazel for five centuries, suggesting a decline of population and agriculture.