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.
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.