Salicornia bigelovii Torr., also called saltwort, grows in salty environments in marshes and coastal areas from Europe to Asia. A leafless annual that grows to 50 cm, it has tiny flowers with green-jointed succulent stems that form seed-bearing spikes. The spikes contain seeds, which weigh about 1 mg and germinate directly in water. Salicornia takes seven months to produce seeds and ripen, and when planted in December, it can be harvested in July. Salicornia is planted in flooded perimeters similar to rice.
On the salt flats of the United Emirates, called the sabkha, soil salt content can be 30% or higher. Before planting, soils must be flooded with seawater to reduce salt content. According to Dr. Edward Glenn, a research scientist with the University of Arizona, this process is easier than it sounds. Sea salts are very soluble, and flooding three or four times with seawater (salt content of four percent) will reduce soil salt content to about the same as seawater. A high volume, low head pump that can lift water up about 40 feet is required. Such pumps are available in many sizes throughout the world. They are relatively inexpensive and are suitable for agriculture and other uses. Even pumping seawater or other saline water, they can last many years if properly maintained. For example, such pumps are used to drain roadways in the United Arab Emirates, handling water several times saltier than seawater.
The Environmental Resource Laboratory is conducting trials with salicornia in Saudi Arabia, Mexico, and the United Arab Emirates. In the United Arab Emirates salicornia is being evaluated for its potential as fodder. Studies began in 1985 and continue today in on-farm trials and outreach being done by host country development experts.
When harvested, salicornia contains about 30 to 40% salt. It can either be mixed with 50% of another available fodder, such as Rhodes grass (Chloris gayana) or wheat straw, or it must be desalinized before being fed to animals. Removing the salt "is not very cumbersome" according to Glenn. The salicornia is soaked in seawater for an hour, then the water is pressed out. Any agricultural press, such as a cider press, will do. Residual salt is 10 to 11%, comparable to alfalfa.
Although this might seem like an elaborate process for obtaining fodder, salicornia has been enthusiastically received by farmers because of the amount of land that can now be exploited, and because they no longer need to import fodder. Also, in the United Arab Emirates, many of the field laborers are from rural areas of India and Pakistan. The researchers found that these laborers were already familiar with the basic techniques of growing crops like salicornia.
In Sonora, Mexico, salicornia was evaluated for its potential as an oilseed crop. Yields exceeded freshwater oilseed crops such as sunflower and soybean. In 1982, trials began on coastal soils irrigated from seawater wells. Over six years, trials were conducted in two separate fields. Table 1 shows average oil production for salicornia, soybean, and sunflower.
When crushed for oil, salicornia was found to produce 30% oil and 70% meal. The protein content of the meal is 42 to 45%. When used as hay including the seeds, salicornia is about 10 to 12% protein; without the seeds it is 5 to 7% protein.
Oil and meal were extracted by normal milling equipment, producing a high-quality, nutty-tasting oil. Any cold press could be successfully used. The meal contains saponins (detergent-like compounds) and requires a cholesterol amendment before being used as chicken feed. Pakistan will hopefully be the next country where salicornia will be produced, said Glenn. Scientists are meeting with Pakistani government officials to discuss the possibility.
Salicornia is a promising option for farmers stranded in the more desolate and salty regions of the world, providing nutritious fodder and valuable oil where little else could survive.
Glenn, E. P., J. O'Leary, M. Watson, T. Thompson, and R. O. Kuehl. (1991).Salicornia bigelovii Torr.: An oilseed halophyte for seawater irrigation. Science, 251, 1065-67.
Dr. Edward P. Glenn
Environmental Research Laboratory
University of Arizona
2601 E. Airport Dr.
Tucson, Arizona 85706-6985 USA
Tel: (602) 741-1990
Fax: (602) 573-0852