Byproducts from corn processing may help remove lead, copper, zinc and other heavy metals from industrial wastewater. ARS scientists developed a way to combine corn fiber and other corn products with citric acid to form a material that binds with heavy metals. The process could help industry safely treat heavy metal-laden wastewater. In the process, citric acid is heated to release hydrogen atoms from its molecules. Those molecules then bond readily with corn byproducts to form the material that will bind with heavy metals in wastewater. Stringent regulations require industry to remove heavy metals from wastewater before discharging the water. The new process is cheaper than petroleum-based products and uses corn, a renewable resource. The technology could also help farmers by increasing the value of corn and opening new markets for the crop.
National Center for Agricultural Utilization Research, Peoria, IL
Robert E. Wing/David J. Sessa, (309) 681-6353/6351, wingre@mail.ncaur.usda.gov, sessadj@mail.ncaur.usda.gov

Sunflowers can be a combination snow fence, wind barrier and cash crop in the normally fallow years between wheat crops in the central Great Plains. ARS researchers found that one key to getting the full benefit of sunflowers' wind protection and snow capturing is to set the combine's harvest head as high as possible, leaving the stalks about 30 inches tall. The standing stalks almost completely prevent soil from being blown away by spring winds that easily exceed 30 mph. The stalks also can trap three to 10 times more snow than would normally accumulate when no crop residues are present during blizzards common to the region. The trapped snow replenishes 3 to 9 inches of the soil moisture used by the growing sunflowers. This compensates for most of the water used by the thirsty sunflowers, making the practice worthwhile for farmers. They should earn more money than if they grew only wheat, even when yields of wheat or other rotated crops are lower because some of "their" water is used instead by sunflowers.
Central Great Plains Research Station, Akron, CO
David C. Nielsen, (970) 345-2259, dnielson@lamar.colostate.edu

Irradiation could have potential as a safe new alternative for preventing water spinach, a tasty Asian plant, from posing a threat to Florida's Everglades. The plant is a popular iron-rich food in Asia, and many of Florida's Asian immigrants want fresh water spinach on their menu. But it's illegal to buy or sell fresh water spinach in Florida because if cuttings escape from farms or home gardens into Everglades tributaries, they can quickly crowd out native plants. Under a state certification program, some Florida farmers grow water spinach. But they may ship it only to markets outside the state. Recently, ARS scientists found a technique that could enable qualified farmers to grow and sell the crop inside the state and still protect the Everglades. The ARS scientists showed that harvested water spinach becomes unable to grow and spread when exposed to only 0.25 kiloGray of cobalt radiation. The Food and Drug Administration already allows up to 1 kiloGray of irradiation to delay ripening of fruits and vegetables. The new tactic would prevent unauthorized home-growers from starting their own crop and endangering the Everglades. But the approach must pass further research tests as well as state approvals.
Aquatic Weed Control Research Laboratory, Fort Lauderdale, FL
Thai K. Van, (954) 475-0541, thaivan@netrunner.net

Native desert grasses took 51 years to begin to re- establish themselves in a former grassland overrun by shrubs as a result of excessive grazing in the late 1800's and early 1900's. And fences to keep out grazing animals didn't help. This finding emerged from a 60-year-old-and-still-going study in southern New Mexico's Chihuahuan Desert. The long recovery time shows that management strategies followed through the 1980's need updating. These strategies included fencing and reseeding, with an assumption these would quickly spur a switch back to grassland. Shrubs have been periodically and selectively removed from certain study plots since 1938. These plots were fenced to keep out cattle, jack rabbits and other wildlife. But the fencing had no effect on the grasses' comeback. Repeated shrub removal and rainfall played roles, but very slowly. Only in 1989 did native desert grasses and other desirable plants start to show up in bare ground between shrubs. By 1995, the grasses were spreading throughout the bare areas. Long before, people had begun to doubt the grasses would ever return. ARS scientists are now looking for new ways to manage shrublands and grasslands as the complex, fragile--though rugged- looking--ecosystems they are. They plan to target sites for remediation based on natural advantages they may possess, such as streams or springs.
Jornada Experimental Range, Las Cruces, NM
Kris M. Havstad, (505) 646-4842, khavstad@nmsu.edu

ARS scientists have found that beneficial fungi are key to survival of fragile sagebrush seedlings planted to reclaim strip-mined rangeland in the West. The fungi, which dwell on roots, have hairlike filaments that funnel water and nutrients to the roots, thus extending their reach. Wyoming state law and federal reclamation regulations require replanting native vegetation such as Wyoming big sagebrush after mining. Mining companies typically salvage and store the topsoil--for as long as several years--and put it back only after they've finished mining a site. But when salvaged topsoil is stored that long, the root-helping fungi die off. For this reason, salvaged soil should be used within a few months on other sites in the area where mining activities have ended. Scientists conducted a greenhouse study using soil from a sagebrush-grassland site on a coal mine in northeastern Wyoming. Sagebrush seedlings grown in fresh topsoil with the fungi present lasted 3 to 5 days longer in dry soil. This could be just enough time to tide the seedlings over until the next rain. Ability to tolerate drought is critical to survival of plants in arid and semiarid lands of the West, especially in reclaimed soils that tend to hold less water.
Rangeland Resources Research Unit, Cheyenne, WY
Gerald E. Schuman, (307) 772-2433, gschuman@lamar.colostate.edu

Fast-growing hybrid poplars may offer an environmentally friendly way to re-use leftover irrigation water that drains from irrigated farmlands. The trees could reduce the size and number of costly evaporation ponds needed today to collect salinedrainage water. Because hybrid poplars can be harvested for everything from toothpicks and veneer to high-quality paper, they could also provide a new source of income for growers. Ecolotree, Inc., Iowa City, IA, provided six-inch cuttings for a test in California. When the test ended 5 months later, trees averaged 6 feet tall. Employing hybrid poplars to recycle water isn't a new idea, but the ARS study is apparently the first to scrutinize their ability to withstand chloride salt, boron and selenium in amounts sometimes present in irrigation drainage. Of the eight kinds of hybrid poplars tested, none was as salt-tolerant as eucalyptus--another fast- growing species sometimes chosen for water re-use. But the market for poplar pulp and other wood products is stronger than that for eucalyptus. Findings should apply not only to California but also parts of Arizona, New Mexico, Colorado and Texas. Hybrid poplars might also help use up saline effluent from factories around the nation.
U.S. Salinity Laboratory, Riverside, CA
Michael C. Shannon, (909) 369-4815, mshannon@ussl.ars.usda.gov
Water Management Research Unit, Fresno, CA
Gary S. Banuelos, (209) 453-3115, sdowney@asrr.arsusda.gov

Bluegill, bass and catfish now thrive in the South's silty, warm-water streams. Weekend anglers may be glad to hear that "sticks and stones" can protect those waters--and their fish--for generations to come. The sticks are dormant willow posts planted in eroding streambanks. These cuttings come to life in spring and grow branches and roots to protect the streambank from erosion. The posts can range from 7 to 20 feet long. The stones are quarried stone structures of six to eight inches in diameter--"fingers" set perpendicular to the current, or "toes" set parallel to the bank--that put a brake on speeding currents that can erode stream banks. Scientists conducted a 3-year study to determine which technique-- stones or sticks--is most effective in restoring fish habitats in a stream damaged by extreme erosion. Stone treatments seem slightly better based on the size of fish. But they are more expensive. Willows cost only a fraction as much as stone treatments and--while they may die off--living or dead they create habitat for other wildlife.
National Sedimentation Lab, Water Quality and Ecology Research Unit, Oxford, MS
F. Douglas Shields, Jr., (601) 232-2919, shields@sedlab.olemiss.edu

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