A pilot project to see if cash crops can be grown in the salty ground of India’s coastal areas was launched in 2010. The area in Tamil Nadu state will house dozens of species of halophytes – or salt-loving plants – that can be used for producing cash crops.
Halophytes can be used to produce edible oils, medicines, vegetables, and cattle and fish feed. Halophytes can be found throughout the coastal areas of India.
Saline water plants can also be used to produce fine chemicals, biofuels and even building materials. Field studies conducted in the US and East Africa have suggested that halophytes such as sea asparagus can be grown as commercial crops.
A halophyte is a plant that grows where it is affected by salinity in the root area or by salt spray, such as in saline semi-deserts, mangrove swamps, marshes and sloughs, and seashores. An example of a halophyte is the salt marsh grass Spartina alterniflora (smooth cordgrass). Relatively few plant species are halophytes – perhaps only 2% of all plant species. The large majority of plant species are “glycophytes”, and are damaged fairly easily by salinity.
One quantitative measure of salt tolerance is the “total dissolved solids” in irrigation water that a plant can tolerate. Sea water typically contains 40 grams per litre (g/l) of dissolved salts (mostly sodium chloride). Beans and rice can tolerate about 1-3 g/l, and are considered glycophytes (as are most crop plants). At the other extreme, Salicornia bigelovii (dwarf glasswort) grows well at 70 g/l of dissolved solids, and is a promising halophyte for use as a crop. Plants such as barley (Hordeum vulgare) and the date palm (Phoenix dactylifera) can tolerate about 5 g/l, and can be considered as marginal halophytes