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.
Uruk period
In the agricultural sphere, several important innovations were made between the end of the Ubayd period and the Uruk period, which have been referred to in total as the 'Second Agricultural Revolution' (the first being the Neolithic Revolution). A first group of developments took place in the field of cereal cultivation, followed by the invention of the ard—a wooden plough pulled by an animal (ass or ox)—towards the end of the 4th millennium BC, which enabled the production of long furrows in the earth. This made the agricultural work in the sowing season much simpler than previously, when this work had to be done by hand with tools like the hoe. The harvest was made easier after the Ubayd period by the widespread adoption of terracotta sickles. Irrigation techniques also seem to have improved in the Uruk period. These different inventions allowed the progressive development of a new agricultural landscape, characteristic of ancient Lower Mesopotamia. It consisted of long rectangular fields suited for being worked in furrows, each bordered by a little irrigation channel. According to M. Liverani, these replaced the earlier basins irrigated laboriously by hand. After the end of the 5th millennium, tree crops were also developed in the whole Middle East; in Lower Mesopotamia, the date palm began to be cultivated and gardens and orchards containing them became a characteristic element of Mesopotamian architecture. This system which progressively developed over two thousand years enabled higher yields, leaving more surplus than previously for workers, whose rations mainly consisted of barley. The human, material, and technical resources were now available for agriculture based on paid labour, although family-based farming remained the base unit. All of this undoubtedly led to population increase and thus urbanisation and the development of state structures.