Biosalinity is the study and practice of using saline (
salt
Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quant ...
y) water for irrigating
agricultural crops
A crop is a plant that can be grown and harvested extensively for profit or subsistence. When the plants of the same kind are cultivated at one place on a large scale, it is called a crop. Most crops are cultivated in agriculture or hydroponics ...
.
Many arid and semi-arid areas actually do have sources of water, but the available water is usually
brackish
Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estu ...
(0.5–5g/L salt) or
saline (30–50g/L salt). The water may be present in underground
aquifer
An aquifer is an underground layer of water-bearing, permeable rock, rock fractures, or unconsolidated materials ( gravel, sand, or silt). Groundwater from aquifers can be extracted using a water well. Aquifers vary greatly in their characteris ...
s or as
seawater
Seawater, or salt water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, 35 ppt, 600 mM). This means that every kilogram (roughly one liter by volume) of seawater has appr ...
along coastal deserts. With traditional farming practices, saline water results in soil
salinization, rendering it unfit for raising most crop plants. Indeed, many arid and semi-arid areas were simply considered unsuitable for agriculture, and
agricultural development
Agricultural expansion describes the growth of agricultural land (arable land, pastures, etc.) especially in the 20th and 21st centuries.
The agricultural expansion is often explained as a direct consequence of the global increase in food and ene ...
of these areas was not systematically attempted until the second half of the 20th century.
Research in biosalinity includes studies of the
biochemical and
physiological mechanisms of salt tolerance in plants,
breeding
Breeding is sexual reproduction that produces offspring, usually animals or plants. It can only occur between a male and a female animal or plant.
Breeding may refer to:
* Animal husbandry, through selected specimens such as dogs, horses, and ra ...
and selection for salt tolerance (
halotolerance
Halotolerance is the adaptation of living organisms to conditions of high salinity. Halotolerant species tend to live in areas such as hypersaline lakes, coastal dunes, saline deserts, salt marshes, and inland salt seas and springs. Halophiles are ...
), discovery of periods in a crop plant's life cycle when it may be less sensitive to salt, use of saline
irrigation
Irrigation (also referred to as watering) 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 devel ...
water to increase desirable traits (such as
sugar concentration in a fruit) or to control the ripening process, study of the interaction between salinity and
soil
Soil, also commonly referred to as earth or dirt
Dirt is an unclean matter, especially when in contact with a person's clothes, skin, or possessions. In such cases, they are said to become dirty.
Common types of dirt include:
* Debri ...
properties, and development of naturally salt-tolerant plant species (
halophyte
A halophyte is a salt-tolerant plant that grows in soil or waters of high salinity, coming into contact with saline water through its roots or by salt spray, such as in saline semi-deserts, mangrove swamps, marshes and sloughs and seashores. Th ...
s) into useful agricultural crops. See also
halophile
The halophiles, named after the Greek word for "salt-loving", are extremophiles that thrive in high salt concentrations. While most halophiles are classified into the domain Archaea, there are also bacterial halophiles and some eukaryotic species, ...
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...
, which thrive under conditions of high salinity.
When properly applied (watering well in excess of
evapotranspiration
Evapotranspiration (ET) is the combined processes by which water moves from the earth’s surface into the atmosphere. It covers both water evaporation (movement of water to the air directly from soil, canopies, and water bodies) and transpi ...
, maintaining
soil structure
Soil structure describes the arrangement or the way of soil in the solid parts of the soil and of the pore space located between them. It is determined by how individual soil granules clump, bind together, and aggregate, resulting in the arrangem ...
for excellent drainage), brackish-water irrigation does not result in increased salinization of the soil. Sometimes this means that farmers have to add extra water after a rainstorm, to carry salts back down to below the root zone.
See also
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* {{annotated link, Soil salinity control
External links
Organizations involved in biosaline research and development
CGIAR: Consultative Group on International Agricultural ResearchICBA: International Center for Biosaline AgricultureUSDA's George E. Brown Jr. Salinity LaboratorySalt Farm TexelThe Seawater Foundation
Popular reviews
*Glenn, E. P.; Brown, J. J.; O'Leary, J. W. (1998)
"Irrigating Crops with Seawater,"Scientific American', Vol. 279, no. 8, Aug. 1998, pp. 56–61.
Irrigation
Saline water