At 13 months, salt-tolerant poplars planted at
Oremet Titanium, Inc., in Albany, Ore., are already 12 feet tall.
Thirsty Hybrid Poplars Recycle Irrigation WaterBy
Hybrid poplars may help the environment by drinking used irrigation
water laden with salt, boron and selenium. Scientists say the
fast-growing trees may also provide a new source of income for farmers
who grow irrigated crops like tomatoes, melons, cotton and alfalfa in
Today, some growers drain leftover irrigation water to evaporation
ponds. That helps prevent minerals in the drainage water from flowing
into rivers, streams and the underground water supply, called
groundwater. In the future, with the help of the water- loving
poplars, growers may need fewer--and smaller--evaporation ponds. This
would reduce maintenance, including the costs of keeping wildlife from
ponds where high levels of minerals accumulate.
The idea of using hybrid poplars to recycle water isn't new. But an
Agricultural Research Service
study of eight different kinds of candidate hybrid poplars was among
the first to examine the trees' ability to withstand chloride salt,
boron and selenium in the amounts sometimes present in irrigation
No experimental poplar was as salt-tolerant as eucalyptus, an
extremely fast-growing species sometimes chosen for water re-use. The
market for hybrid poplar is stronger, however. It can be made into
everything from toothpicks and high-quality veneer to paper.
Michael C. Shannon of the U.S.
Salinity Laboratory at Riverside, Calif., and Gary S. Banuelos
of the ARS Water Managment
Research Laboratory at Fresno, led the study. Ecolotree, Inc.,
of Iowa City, Iowa, provided 6-inch cuttings, which averaged about six
feet tall by the end of the five-month experiment. Findings should
apply to parts of California, Arizona, New Mexico, Texas and Colorado.
Hybrid poplars might also help re-use saline effluent from factories
around the nation.
An article in the June issue of ARS' monthly magazine, Agricultural
Research, tells more. View it on the World Wide Web at:
Scientific contacts: Michael C. Shannon, ARS U.S. Salinity
Laboratory, Riverside, CA 92507, phone (909) 369-4815, fax (909)
and Gary S. Banuelos, ARS Water Management Research Unit, Fresno, CA
93727, phone (209) 453-3115, fax (209) 453-3122,