The invention of agriculture led to the development of irrigation
The growth of irrigation historically accompanies the development of agriculture. As formerly nomadic people coalesced to form communities, they discovered that plants could be sown, cultivated and harvested seasonally. Thus did farming develop. And fields grew in size when the farmers realized they could divert water from streams and rivers to irrigate their crops.
Early Irrigation
The first attempts at irrigation occurred at the same time agriculture was being developed, about 5,000 years ago. This was typically a simple form of flood irrigation, where channels or furrows were dug in fields and water flooded into them either by hand or with a bucket. This was a labor-intensive, inefficient form of irrigation.
Egypt & Mesopotamia
Egyptians used passive irrigation methods 4,000 years. Irrigation was dependent on a source of water which could vary in availability. Egypt's entire agricultural system was based on exploiting the annual flooding of the Nile River. Water was diverted directly into fields to water crops and to deposit nutrient-rich silt. This is also known as "surface" irrigation. Both the Mesopotamians and Egyptians divided fields into individual basins, allowing irrigation water to flood them. They also used buckets to irrigate if water levels from rivers were too low to flow into fields.
Asia
Traditional methods in China 2,000 years ago involved surface irrigation, with water diverted from rivers. The Chinese also built canals to funnel larger volumes of water to fields at some distance away. As the main cereal crop was rice, field flooding was important for rice germination. During the 9th and 14th Centuries the city of Angkor Wat, in what is now Cambodia, made use of an intricate, large-scale system of canals, ponds and reservoirs for irrigation and water storage.
Europe
The first incidence of large-scale irrigation in Western Europe dates to the Romans 2,000 years ago. The Romans built aqueducts to channel water from the mountains. Gravity brought water down to fields, reservoirs and cities. However, with the collapse of the Roman Empire in the 4th Century, Europe reverted back to traditional, more localized irrigation by tapping river water for fields.
Modern Irrigation Methods
The development of steam and electricity-powered pumps made it possible to marry modern innovations with traditional irrigation methods. Pumps powered by steam or electricity could draw water from deep underground aquifers or rivers and reservoirs far away from farms. Irrigation also became more efficient. Drip irrigation was invented, where fruit and vegetables in a field were irrigated by water droplets, reducing the amount of water wasted as runoff. Spray irrigation was more economical and wasted less water. These innovations were coupled with reusing irrigation runoff, economizing water use.
Tags: water from, fields water, from rivers, into fields, irrigation methods, irrigation water, surface irrigation
