Wood. Straw. Cotton. From fuel to shelter, clothing to containers, the materials from fiber crops are as essential to mankind as food. In the United States, abundant new uses are being developed from the fibers of existing food and feed crops. And over the past ten years, alternative crops such as poplar hybrids, native grasses and imported fiber plants have begun to flourish.

In the southern United States, for example, an African implant called kenaf is gaining commercial ground. A fast-growing — up to 18 feet in six months — fiber crop, kenaf has been selected by the USDA Research Service as one of the most promising fiber alternatives for pulp and paper making. A Texas company markets industrial oil-absorbing and filter products from kenaf and a California company has commercialized a kenaf erosion mat impregnated with grass seeds. In Mississippi, kenaf is being tested in cat litter, soil-free potting mix, soil remediation products and animal bedding.

New uses for fiber abound, but they must translate into marketable, revenue-generating products. A Georgia company is using cotton, peach pits, peanut hulls and ag waste to produce a high-grade activated carbon for water filtration systems. And in Nebraska, the Ogallala Down Company has developed a pillow made from milkweed’s silky fibers and goose down.

In Minnesota, fiber could become the financial backbone of many farms. Alfalfa, poplar trees, wheat straw, and switchgrass aren’t new to Minnesota farms, but several new-use trends are.

Hay ho
ALFALFA

Minnesota ranks seventh in total hay production in the United States. In 1997, Minnesota alfalfa production was 4.9 million tons, up six percent from a year earlier. The average yield was 3.3 tons per acre at an average price of $101 per ton, making the total Minnesota crop worth almost $492 million.

Traditionally raised for livestock feed, alfalfa is being studied for its potential as a fuel source for electricity generation and as a specialized protein source. Alfalfa fiber has been successfully used in designer bowls and handmade paper. Future uses may even include recovering food-grade fiber and enzymes to produce plastics.

“The ultimate goal is to organize a large number of farmers to commercialize alfalfa, make it more profitable and easier to add to our cropping rotations,” says AURI’s Brent Sorenson, a member of the Alfalfa New Products Initiative. ANPI is a cooperative effort between North Dakota, South Dakota, Minnesota, Wisconsin and Michigan. The five states produce more than 25 percent of the total U.S. alfalfa crop. The group has planned an in-depth analysis of alfalfa products’ value and market size to recommend development directions. According to ANPI, the United States is first in the world in alfalfa production, but lags behind Canada and France in exporting products such as alfalfa meal and pellets.

New alfalfa technology, including dehydration and fractionation, could benefit alfalfa producers as well, Sorenson says. “Dehydration allows us to harvest the crop wet and avoid the losses associated with drying it outside .... Wet fractionation presses juices from alfalfa, from which products like proteins and vitamins can be extracted and concentrated.”

Since 1993, members of the Minnesota Valley Alfalfa Producers in Granite Falls, Minn. have been looking for ways to add value to their crops. Currently, they are capitalizing on alfalfa’s high feed value by producing pelletized meal. They’ve teamed up with Northern States Power to research alfalfa stem biomass as an electricity-generating fuel, and eventually will construct a plant to generate 75 megawatts for NSP.

Up on trees
HYBRID POPLARS

Hybrid poplars, fast-growing trees that can produce fiber for paper, building materials and fuel, are growing on about 10,000 acres in Minnesota. Cultivated poplars are carefully planted, fertilized and weeded to produce three to six tons per acre per year. Native poplar forests produce around one ton per acre per year.

While hybrid poplars in Minnesota aren’t yet mature enough for harvest (most are six to seven years away), greater demand for trees in the next century could make it an economically sensible crop for some growers. About 40,000 acres of irrigated hybrid poplars are grown in the Northwest. The wood is used primarily for paper and oriented strand board.

The Minnesota Hybrid Poplar Research Cooperative is developing varieties suited to Minnesota conditions, says AURI microbiologist Edward Wene. The co-op is comprised of AURI, the U of M-Crookston, the Natural Resources Research Institute in Duluth, and industry members, including Boise Cascade, Champion, Blandin, Potlatch and Minnesota Power.

Pulp non-fiction
AG FIBER FOR PAPER

When it comes to paper products, “one of the positive things going for agricultural fiber is that it’s easier to pulp than wood fiber,” says AURI’s Bill Stoll, who has guided several fiber entrepreneurs.

With aspen stands expected to be at a low cycle in the next 10 to 20 years, and the increasing price of pulpwood, Sorenson says, pulping ag fibers looks promising for Minnesota. “There are not very many areas in the United States where we have such intense agriculture so close to large paper producers,” he says. “It gives us an advantage.”

Wheat, oats and barley straw are potential paper fiber sources. The Northwest Minnesota Foundation recently awarded a grant of $30,000 to the Future Fiber Partners Group to continue researching straw and wood pulp blends for fine paper manufacturing. The grant matches funding committed by the Red Lake Electric Cooperative, Blandin Corporation, AURI and the Minnesota Barley Research and Promotion Council.

The Legislative Commission on Minnesota Resources has given preliminary approval to funding pilot-plant work. Sorenson says the goal is “to find a process that gets a significant return for their product, not just covering costs.” If the research and economic analysis pan out, the group hopes one or two small scale pulp mills could be built in northwestern Minnesota.

Straw-built
STRAWBOARD PLANTS

Several companies have started strawboard plants in the upper Great Plains, and many more are on the drawing board. Even lumber companies such as Boise-Cascade and Willamette Industries are exploring straw as a partial replacement for wood-based construction materials. Many of the projects in this arena are sponsored by AARCC, the USDA’s Alternative Agricultural Research and Commercialization Corporation. Phenix Biocomposites, Inc., an AARCC and AURI client, is building a state-of-the-art manufacturing facility in Mankato, Minn. The company will produce a particleboard from wheat straw and soy stalks. It expects to process 100,000 tons of wheat straw and soybean stalks in 1999.

PrimeBoard, Inc. of Wahpeton, N.D. has been making particleboard from wheat straw since 1995. The strawboard is lighter than wood particleboard, resists moisture better and doesn’t contain urea formaldehyde. PrimeBoard sells its product across the United States for store fixtures, furniture, countertops, kitchen cabinets and architectural millwork.

In Electra, Texas, Agriboard Industries is making load-bearing panels for building construction. Agriboard laminates compressed wheat straw between two sections of oriented strand board to make exterior wall, roof and floor panels that are quiet, strong, fire resistant and energy efficient.

Gridcore Systems International of Long Beach, Calif., engineers honeycomb panels from recycled fibers or ag fibers such as kenaf, rice, wheat straw and oil palm fronds. The resulting hollow panels are strong, lightweight and formaldehyde-free. The manufacturing process was invented by USDA’s Forest Products Research Laboratory.

Throw the switch

Switchgrass for electricitySwitchgrass, found extensively on land set aside in the Conservation Reserve Program, is being looked at for its energy-producing potential. In Iowa, a proposal to burn switchgrass to generate electricity has received a $6 million grant from the U.S. Department of Energy and $4 million from the U.S. Department of Agriculture. Switchgrass burns cleaner than coal, say project proponents.

An acre of switchgrass produces 4 to 6 tons annually. In Minnesota, switchgrass sells for around $30 per ton. In addition to generating electricity, switchgrass enthusiasts intend to experiment with switchgrass as a fuel for residential heating or burners for drying corn.

Focus on the future ...

AURI and U of M researchers recently patented a “Microfibrulated Process” that can break down almost any ag fiber — cornstalks, soy or sunflower hulls, sugar beet fiber — into micro fibers. The ultra-fine material can then be processed into biodegradable film coatings, degradable plastics, food fillers and even nutritional supplements to reduce cholesterol.

Energy production is another fiber use often touted by researchers, but commodity prices and transportation costs will continue to determine the economic feasibility of such ventures, Wene says. Availability of fossil fuels and proximity to energy producers will also have an effect on any use of fiber crops as fuel.

Other future fiber uses include waste fiber as reinforcement material for lightweight concrete mixes, and even fabrics from hemp.