Agrarian society
Agrarian society were preceded by hunter and gatherer and horticultural societies and transition into industrial society. The transition to agriculture, called the Neolithic Revolution, has taken place independently multiple times. Horticulture and agriculture as types of subsistence developed among humans somewhere between 10,000 and 8,000 years ago in the Fertile Crescent region of the Middle East. The reasons for the development of agriculture are debated but may have included climate change, and the accumulation of food surplus for competitive gift-giving. Most certainly there was a gradual transition from hunter-gatherer to agricultural economies after a lengthy period when some crops were deliberately planted and other foods were gathered from the wild. In addition to the emergence of farming in the Fertile Crescent, agriculture appeared in: by at least 6,800 B.C.E. in East Asia (rice) and, later, in Central and South America (maize and squash). Small-scale agriculture also likely arose independently in early Neolithic contexts in India (rice) and Southeast Asia (taro). However, full dependency on domestic crops and animals, when wild resources contributed a nutritionally insignificant component to the diet, did not occur until the Bronze Age.
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.