Method

Irrigation

Overview

Irrigation in agriculture is the practice of applying controlled amounts of water to land to help grow crops, landscape plants, and lawns. Irrigation has been a key aspect of agriculture for over 5,000 years and has been developed by many cultures worldwide. Irrigation helps to grow crops, maintain landscapes, and revegetate disturbed soils in dry areas and during times of below-average rainfall. In addition to these uses, irrigation is also employed to protect crops from frost, suppress weed growth in grain fields, and prevent soil consolidation. It is also used to cool livestock, reduce dust, dispose of sewage, and support mining operations. Drainage, which involves the removal of surface and sub-surface water from a given location, is often studied in conjunction with irrigation. Irrigation and drainage improvements are not necessarily mutually exclusive. Often both may be required together to assure sustained high-level production of crops. For a discussion of the role of drainage practices in agriculture .

Several irrigation methods differ in how water is supplied to plants. Surface irrigation, also known as gravity irrigation, is the oldest form of irrigation and has been in use for thousands of years. In sprinkler irrigation, water is piped to one or more central locations within the field and distributed by overhead high-pressure water devices. Micro-irrigation is a system that distributes water under low pressure through a piped network and applies it as a small discharge to each plant. Micro-irrigation uses less pressure and water flow than sprinkler irrigation. Drip irrigation delivers water directly to the root zone of plants. Subirrigation has been used in field crops in areas with high water tables for many years. It involves artificially raising the water table to moisten the soil below the root zone of plants.

Irrigation water can come from groundwater (extracted from springs or by using wells), from surface water (withdrawn from rivers, lakes or reservoirs) or from non-conventional sources like treated wastewater, desalinated water, drainage water, or fog collection. Irrigation can be supplementary to rainfall, which is common in many parts of the world as rainfed agriculture, or it can be full irrigation, where crops rarely rely on any contribution from rainfall. Full irrigation is less common and occurs only in arid landscapes with very low rainfall or when crops are grown in semi-arid areas outside the rainy season.

The environmental effects of irrigation relate to the changes in quantity and quality of soil and water as a result of irrigation and the subsequent effects on natural and social conditions in river basins and downstream of an irrigation scheme. The effects stem from altered hydrological conditions resulting from the installation and operation of the irrigation scheme. Amongst these problems is the depletion of underground aquifers through overdrafting. Soil can be over-irrigated due to poor distribution uniformity or management wastes water, chemicals, and may lead to water pollution. Over-irrigation can cause deep drainage from rising water tables, which can lead to irrigation salinity problems, requiring watertable control through some form of subsurface land drainage.

Overview adapted from Wikipedia (CC BY-SA 4.0; see the article history for authors).

Possible passages

Found by search and not yet checked by a person; they may only mention the idea in passing.

It is about the rising of the Dog-star that irrigation is so particularly beneficial; but even then it ought not to be in excess, as the roots are apt to become inebriated, and to receive injury therefrom. Care should be taken, too, to proportion it to the age of the tree, young trees being not so thirsty as older ones; those too which require the most water, are the ones that have been the most used to it. On the…
the Elder Pliny, The Natural History of Pliny, Volume 3
The chapter “CHAP. 40.—METHODS OF IRRIGATION.” is titled for Irrigation; states what Irrigation is.
Read the chapter · Open in the reader
Aye,—many things, truly, said Adimantus, and quite in accordance with their spirit.—And you know, said I, that the domestics likewise of such families, such of them as would be thought good-natured, sometimes say privately the very same to the sons; and if they see either a debtor whom the father does not sue, or any one otherwise acting unjustly, they exhort him to punish all such persons when he comes to manhood…
Plato, The works of Plato
States what Irrigation is.
Read the chapter · Open in the reader
Nothing can rob a man of the happiness of successful achievement in an important piece of work, unless it be the proof that after all his work was bad. There are many forms of such satisfaction. The man who by a scheme of irrigation has caused the wilderness to blossom like the rose enjoys it in one of its most tangible forms. The creation of an organization may be a work of supreme importance. So is the work of…
Bertrand Russell, The conquest of happiness
Names Irrigation.
Read the chapter · Open in the reader

Irrigation

Overview

Possible passages

Philosophers who discussed Irrigation

Related ideas

Place in the tradition