Fabric products help farmers put the green back in agriculture.
By Jamie Swedberg
The market for agricultural specialty fabrics in the United States is a paradox.
On one hand, agriculture has suffered terribly over the last two years for reasons related to the current recession. Accordingly, sales of agricultural products have dropped or stagnated.
“For the first time in 29 years, the ag market fell at the same time as the general economy did,” says Barry Goldsher, president and CEO of ClearSpan Fabric Structures Intl., Dyersville, Iowa. “In prior recessions, like during 9/11 and in the 1989–1990 downturn, the country went into a small economic tailspin, but farmers didn’t at all. The farmers were soaring; they were enjoying the greatest of times. But this time, ag actually started to fall before the general economy, when the oil prices went to $140 a barrel. Their fertilizer inputs and heating costs—all of that was tied to petroleum. It just put them into a tailspin. They’re just now starting to recover a little.”
On the other hand, fabric and membrane manufacturers and fabricators are finding new opportunities within agriculture. Products that help address the fuel-cost problem are increasingly welcome in the agriculture and food and flower distribution industries. And as stricter regulations and public demand nudge farming toward more sustainable practices, products that can aid in these efforts are also gaining popularity.
Fabrics help with heating and cooling
Southwestern Sales Co. of Rogers, Ark., has manufactured fabric curtains for the poultry industry since 1977. Over the years the company has also expanded into tarps and covers. But recently, customer demand has led the company to design products that help poultry, hog and dairy farmers save energy.
“The cost of fuel was going up, and our customers were telling us it was getting harder and harder to break even,” says Gerald Barrett, Southwestern’s sales and marketing manager. “They have to maintain certain environmental parameters inside the facility, or they have issues with the health of the animals.”
One of the biggest issues was the amount of heat loss through the sidewalls of the building. Southwestern started manufacturing insulated curtains, offered in a couple of basic varieties tailored for the needs of farmers in different regions.
In the southern U.S., winter days can be brutally cold—but then, two or three days later, the weather can turn mild. So these farmers gravitate toward flexible woven polyethylene with a bubble-wrap-like air layer sandwiched between the layers. This type of curtain folds up easily when the curtain is raised on warm days.
Up north, once it’s cold, it stays cold for months. Farmers dealing with these conditions prefer vinyl curtains with one or more bubble layers. They don’t fold as compactly or easily, but they’re sturdier and heavier.
Southwestern manufactures similar insulated fabric panels for the end doors of the houses. The doors are large enough to drive a truck through, and although they’re often kept closed for as long as six months at a time, they tend to crack and gap over time.
“We designed a panel with zippers in it along the door frame,” says Barrett. “They tack this up, and then when they need to use the door, they unzip the center panel and roll it up out of the way.”
Barrett says with the insulated curtains and end door panels, farmers are finding that not only do they save on fuel in the winter, they save in the summertime, too.
“In the summertime, the challenge is to cool the animals inside the house,” he says. “With insulated curtains in the summer, they’re finding that it takes longer for the houses to heat back up. They have to run their fans less, and they have to use less water in their cooling systems.”
Poultry house ventilation fans are another spot where fabric products can help save energy. Ventilation is a life-or-death matter in animal confinement, so houses are built with enough fans to handle a worst-case scenario. Most of the time, several of the fans lie dormant, closed only with leaky gravity louvers.
“We came up with a cover that could go on the outside of the fan,” says Barrett. “Most of these fans, for efficiency’s sake, have a cone like a jet engine. These covers have elastic material around the perimeter, and you just stretch it and put it over the cone. If for some reason the fan comes on in an emergency, the exhaust will just blow the cover off, and you’ll still have the air movement you need within the house.”
ClearSpan Fabric Structures has taken a different approach to animal confinement: making the whole building out of fabric.
“When you compare fabric buildings with noninsulated metal buildings, they tend to stay more than 10 degrees cooler in the summer,” Goldsher says. “Fabric doesn’t store the heat, so as soon as the sun goes down the cover gets cool. But steel gets hot and stays hot. In the winter, because our buildings let sunlight in, they start to warm up during the day and are about 10 degrees warmer than a noninsulated metal building.”
ClearSpan generally avoids adding insulation panels to fabric buildings because the panels block the natural light. Although the fabric buildings are not quite as energy efficient as insulated metal buildings, Goldsher says there are other reasons farmers choose them: portability, lower price (the fabric sheds are roughly half the cost of an equivalent wooden or steel structure), permit or property tax reasons, or the health of the animals.
“One of the the unique selling propositions, no matter what the use of the fabric structure, is that no artificial light is needed during the day,” he says. “But for agriculture, the natural light actually improves animal health. Sheep, goats, cows, chickens—they excel under that natural light. The environment inside is more free of bacteria, the feed-to-weight-gain ratio is better, mortality is lower, and the animals are just happier.”
Biodegradable materials assist agronomic cycle
Organic farmers strive to grow their crops in as sustainable a manner as possible. But because plastic mulching is the most efficient way to block weeds without the use of herbicides, they often end up having to buy petroleum-based mulch films. What’s worse, the films are single-use, and have to be pulled up from the fields at the end of the season—which usually involves machinery and still more petroleum use.
Novamont, a company based in Novara, Italy, has come up with a solution to this thorny problem. In the late 1990s, it brought to the market a resin called Mater-Bi®, a bioplastic made primarily of vegetable starch and vegetable oil. The most common use of the resin is the manufacture of biodegradable grocery bags. But more recently, Novamont has started making Mater-Bi mulch films.
“This is a way of closing the loop,” says marketing director Andrea Versari. “At the end of the agronomical cycle, this film does not need to be collected because it is biodegradable. It can be released in the soil because it transforms, in the presence of carbon dioxide and water, into humus.”
The film can be a tough sell because it’s substantially more expensive than polyethylene films manufactured for weed prevention. That’s why Versari stresses the importance of strict standards and clear terminology.
“Sometimes in the market, we see so-called degradable materials that are, for example, polyethylene with additives,” he says. “They claim to be biodegradable, but in their case, it’s simple fragmentation. The plastic just falls apart into tiny pieces of plastic—it never composts or goes away. These products are, of course, very cheap. But they are not the same thing.”
In general, bioplastics tend to do better in the EU because of stricter standards for waste disposal. But this is one instance where Versari suspects Americans may adopt the technology more enthusiastically. It has to do with operational efficiency: the time farmers save by not having to pull up the film.
“In Europe, the farms are very small, and generally the family are the only workers,” he explains. “So they are using their own time, and it’s part of their lifestyle. But with larger farms, as in the United States, the difference is easier to explain because they are using workers to collect the film. That’s money out of their pocket.”
Fabric structures prevent pollution
Composting is a core principle of sustainable farms and cities. But if done incorrectly, it can also be a source of pollution.
“Let’s say a municipality is accepting food scraps, leaves, brush and other garbage that they want to compost,” says ClearSpan’s Barry Goldsher. “If they are composting outside, all it takes is a heavy rainstorm to make a godawful mess. Often all of the feedstuffs for the process will end up in the groundwater.”
As a result, new federal and state regulations are popping up, requiring composting operations to be covered. Once again, it’s a job for fabric.
“A fabric structure is desirable because it’s low in cost, and it’s very tall and open, so it’s easy to ventilate,” Goldsher says. “The process of composting creates an awful lot of ammonia and corrosive gases, and fabric resists it better than any other product out there. If it were steel roofing and siding, it would rust quickly. And again, you have the benefit of natural daytime lighting.”
Gases are an even more acute problem for livestock operations. The concentrated animal feeding operations (CAFOs) that are the source of most U.S. pork are notorious for foul odors—the kind that sicken people and make nearby homes impossible to sell. That’s why John Baumgartner, president of Baumgartner Environics Inc., Olivia, Minn., decided to develop a new kind of lagoon cover called Bio-Cap®.
Manure lagoons are anaerobic systems. When organic matter breaks down anaerobically—without air—there are basically two types of bacteria at work: acetogens and methanogens. Acetogens break down long-chain fatty acids into short-chain volatile fatty acids. Many of these compounds are intensely odorous. Methanogens break down the short-chain volatile fatty acids into compounds that don’t smell, such as carbon dioxide, water vapor, nitrogen gas and methane.
“I like to describe the acetogens as being the big brother,” says Baumgartner. “They’re a little stronger, a little faster, a little tougher. The methanogens are like the little brother. They try hard, but they just can’t keep up. So often there is a tremendous amount of odor released from these systems because they are out of balance. The Bio-Cap cover helps remedy this by providing a nice environment for the methanogens. They form a biofilm in the cover, which floats on the surface of the lagoon. When the volatile organic compounds diffuse from the lower depths of the lagoon, the methanogens intercept these bugs and metabolize them, greatly reducing the odor emissions.”
Bio-Cap is a permeable polypropylene nonwoven geotextile, needlepunched with a closed-cell foam for flotation. Its permeability solves another of the livestock industry’s persistent problems: not only is it approximately one-third the price of a traditional HDPE cover, it requires less upkeep.
“If you put on an impermeable cover, like an HDPE cover, you need to manage the gas, because it’s not going to go anywhere,” he explains. “So you’ve got to collect that gas and do something with it, or you will destroy the system. Well, the Bio-Cap lets rainfall come right into the lagoon, right through the cover, and it lets the non-odorous gases escape into the atmosphere.”
When it comes to removing odors from chicken houses, the strategy is different. The rule of thumb is that about 90 to 95 percent of the odor is carried on the dust particles, because volatile organic compounds are attracted to the particles. Another Baumgartner product, Bio-Curtain®, endeavors to reduce the stink.
Bio-Curtain is a particle control system that treats exhaust air with an electrostatic particle ionization system. The dust particles in the air take on a charge and are attracted to the grounded surface of a fabric curtain on their way out of the building.
The fabric in question is a porous UV-treated polypropylene, similar to shadecloth. It’s hung in a corrosion-resistant metal frame. Many farmers prefer to hang the system on the outside of the barn, because it hides the banks of fans and helps reduce public perception of a smell. (“Sometimes people smell with their eyes,” Baumgartner notes.) But Baumgartner himself likes to mount the system inside the barn for maximum environmental improvement.
“Where possible, I recommend doing it inside the barn because of the production gains, and because it just makes more sense,” he says. “You get better performance because the air is moving a little more slowly inside, so we increase the amount of dust we can get out. Research has shown that less dust leads to an improvement in livestock production and efficiency of feed conversion and reducing mortalities. If we improve the air inside the building, it’s got to be better for the animals and the workers.”