By Rachel Stern
SAN FRANCISCO-Fish bones and manure may be the best solution for reversing desertification, according to scientists at the University of Stavanger in Norway.
A sponge-like biodegradable membrane discovered by a team led by Torleiv Bilstad allows plant roots to retain more water and regulates soil temperature. Made from organic waste matter such as seaweed, fish bones, and chicken manure, the membrane boosts the water-holding capacity of the soil.
“There are no negative effects,” Bilstad told City on a Hill Press (CHP). “Since it’s a biodegradable membrane we don’t do anything artificial to it.”
Bilstad presented his results at the 159th Annual American Advancement of Science (AAAS) meeting this past Sunday, Feb. 18 in San Francisco. Water use in desert environments became a hot topic at the “Science and Technology for Sustainable Well-Being” themed conference.
Currently, the world’s supply of freshwater amounts to about one percent of all available water, according to the Agricultural Research Service. Eighty percent of freshwater consumed world-wide is used for irrigation purposes, of which two-thirds is diverted for human purposes.
According to Bilstad, 27 percent of the world is a desert environment. The majority of irrigation in these environments is lost to evaporation, which the membrane can help reduce by 70 percent.
“An initial powder is absorbed [into] the soil before it forms around plant roots to help them retain water,” he said.
Bilstad, who conducted field research in Norway and Nigeria, compared yields of corn, potatoes, and other crops on arid land with and without the membrane added. In Nigeria, irrigation was cut by 30 to 50 percent. The control field died while the membrane enriched crops flourished.
Adding pigment to the soil—such as that made from eggshells—has the ability to “deflect the sunshine and cool down the soil temperature,” Bilstad said.
The membrane, which can be used along with pesticides or fertilizers, usually accompanies one growing season. The mixture is distributed on seedlings until plants grow tall enough to provide their own shade.
Robert Evans, of the USDA Agricultural Research Service, was open to the idea of testing water-producing technological advances, whether or not they take place in a desert environment.
“If we’re truly going to make more water available, it requires more technologies,” said Evans, who also suggested micro-irrigation in urban environments as a viable alternative.
Whether or not the membrane is effective, Avigad Vonshak of the Jacob Blaustein Institute for Desert Research in Israel, feels it is an over-simplified answer for a broad problem.
“In many places the problem is not just the lack of water, but also the quality of water,” Vonshak told CHP, also pointing out that expensive technologies cannot compensate for a lack of conservation.
Bilstad plans to extend trials of the membrane to Western Europe and Algeria, pointing out that he hopes to obtain international assistance in order to make the crop yield both fruitful and feasible. He also has hopes of forming a company to expand the membrane for wider applications.
