URBANA, Ill. – The splendor of trees and shrubs is apparent in the above-ground portions of the plants, but what lies beneath should not be ignored.
“Soil plays a vital role in the survival of trees and shrubs in the landscape,” University of Illinois Extension educator Andrew Holsinger explains.
Placement of trees is vital to their success, especially when planting in wet soils. Soil texture—the relative ratio of sand, silt, and clay in the soil—is a primary factor in soil moisture retention. Soil texture also influences aeration, or how air moves through the soil. Heavy clay soils tend to have poor aeration and drainage.
There are other factors influencing soil moisture that are important when planting trees and shrubs. These include whether there is a hardpan or other soil interfaces that can interfere with root development. Additional reasons for concern are precipitation patterns or poorly timed or located irrigation systems.
Some trees and shrubs have a greater ability to withstand wet soils than others, Holsinger says. “It is much more cost-effective to plant the right species for the location than trying to adjust the site conditions,” he adds.
A threat to planting in wet soils is frost heaving. Frost heaving is an upward swelling of the soil during freezing conditions caused by ice formation in the pore spaces of soils. Holsinger recommends planting trees and shrubs in wet sites during the early spring to ensure a full season of growth, which can reduce the likelihood of frost heaving.
Initial decisions about placement of a new tree should be guided not only by the mature canopy, but also the expansion of the root system.
“With varying requirements for moisture, it is easy to select trees or shrubs based on their prior performance,” Holsinger says.
Looking at the distribution where trees are located in the wild can guide your thinking when it comes to plant selection. However, species like bald cypress or black gum have more adaptability than their natural distribution would suggest.
“Just because a tree can grow on a wet site doesn’t mean that other characteristics shouldn’t factor into the selection process,” Holsinger says. Insect issues or weak wood should also be considered when selecting trees or shrubs for landscape plantings.
EPA Renewable Fuel Standard rallies soybean oil prices
URBANA, Ill. – From Oct.13 through Nov. 25, the price of January 2017 soybean futures increased by 8.4 percent. The higher prices were led by soybean oil prices, with the January 2017 futures price up 9.4 percent during the same time period, reports University of Illinois agricultural economist Darrel Good.
The latest support for soybean oil prices came on Nov. 23, when the U.S. Environmental Protection Agency released the Renewable Fuels Standard for 2017 and the biomass-based diesel volume requirement for 2018. The renewable fuel requirement for 2017 was established at 19.28 billion gallons, compared to the proposed requirement of 18.8 billion gallons announced in May of this year and the 2016 standard of 18.11 billion gallons. The requirement for biomass-based biodiesel for 2018 was established at 2.1 billion gallons, equal to the proposed requirement, 200 million gallons larger than the 2016 requirement, and 100 million gallons larger than the 2017 requirement. The 2017 requirement for total advanced biofuels was set at 4.28 billion gallons, 670 million gallons larger than the 2016 requirement and 280 million gallons larger than the 2017 requirement. The implied conventional biofuels (ethanol) requirement for 2017 is 15 billion gallons, 200 million gallons larger than the proposed requirement and 500 million gallons larger than the 2016 requirement.
“The larger advanced biofuels requirement for 2017 is expected to result in more biodiesel production than anticipated and may signal even higher requirements in the future,” Good says. “More biodiesel production means more demand for biodiesel feedstocks. The potential magnitude of those increases will be analyzed in an upcoming farmdoc daily article, but will be determined by how much of the total advanced and conventional biofuel requirements are met with biodiesel and how much of the total renewable fuel requirement will be met with the existing stock of biofuels credits in the form of outstanding Renewable Identification Numbers.”
Each gallon of biodiesel production requires approximately 7.4 pounds of feedstock, Good explains. For example, the U.S. Energy Information Administration Monthly Biodiesel Production Report, reported domestic biodiesel production of 142 million gallons in August 2016, with total feedstock consumption of 1.045 billion pounds. The primary feedstocks used in U.S. production of biodiesel are vegetable oils (soybean oil, canola oil, and corn oil); animal fats (poultry, tallow, and white grease); and recycled feeds (yellow grease). Nearly 54 percent (561 million pounds) of the biodiesel feedstocks consumed in August was soybean oil. The USDA’s Nov. 9, 2016 report of World Agricultural Supply and Demand Estimates shows that 5.675 billion pounds of soybean oil were used domestically to produce biodiesel from methyl ester in the 2015-16 marketing year. Use during the current year was projected at 5.95 billion pounds. That number accounts for 29 percent of projected domestic soybean oil consumption and 26 percent of total soybean oil consumption that includes exports.
“The EPA’s final rulemaking implies that domestic biodiesel production and feedstock consumption will exceed previous projections for the current marketing year and beyond,” Good says. “The magnitude of the increase in consumption of soybean oil will depend on the magnitude of increase in biodiesel production and the mix of feedstocks used. It is likely that soybean oil will garner a larger share of the feedstock increase due to a more limited supply of other feedstocks. Each 100-million-gallon increase in biodiesel production might increase domestic soybean oil consumption by 444 million pounds if soybean oil captures 60 percent of the increase in the total feedstock consumption [(100 million gallons X 7.4 pounds) X 0.60].”
The question becomes, how much room is there to expand soybean oil consumption during the current marketing year if the domestic soybean crush is at the projected level of 1.93 billion bushels?
According to Good, the USDA projects soybean oil production during the 2016-17 marketing year at 22.29 billion pounds, consumption at 22.6 billion pounds, and ending stocks at 1.658 billion pounds. Assuming that minimum year-ending stocks are 5 percent of consumption (1.13 billion pounds), then soybean oil consumption can expand by 528 million pounds without requiring an increase in the domestic crush.
“The EPA announcement initially resulted in a surge in soybean oil and soybean prices,” Good says. “Increasing soybean oil consumption for biodiesel production this year and beyond may require the domestic soybean crush to be larger than previously thought, leading to some important longer-term pricing questions. Historically, the domestic crush has been driven by soybean meal demand since meal is not easily stored. If the crush resulted in surplus oil supplies, they were stored. If a shortage of oil occurred, oil prices increased to reduce consumption.
“Because soybean meal is not easily stored, an oil-based crush driven by higher soybean oil prices that resulted in a ‘surplus’ of soybean meal would be expected to result in lower soybean meal prices than would otherwise occur,” Good continues. “The impact of higher soybean oil prices and lower soybean meal prices on the price of soybeans is difficult to anticipate. However, a ‘surplus’ of soybean meal might be expected to result in lower soybean meal prices relative to feed grain prices. The soybean meal to corn price ratio that has ranged from 2.55 to 3.2 in recent years, for example, might decline back to the historical range of 2.0 to 2.5.”
Can houseplants improve indoor air quality?
URBANA, Ill. – In an era of increasing energy prices, many Americans insulate and seal up their homes during the winter months. Although this can result in savings on the monthly power bill, sealing the home can concentrate indoor air pollutants and cause various health problems.
“Making a building airtight limits the exchange of fresh air,” explains University of Illinois Extension educator, Chris Enroth.
Volatile organic compounds, or VOCs, are present in many of our modern-day home furnishings and are a major source of indoor air pollution. Benzene is an example of a VOC and is among the top 20 most widely used chemicals in the U.S. Benzene is present in many types of products such as ink, oils, paints, plastics, rubber, detergent, dyes, and more. Homes with gas ranges or an attached garage typically have higher levels of benzene, as it is present in gasoline and vehicle exhaust.
Humans are another major contributor to indoor air pollution. “Think about the cabin of a passenger plane,” Enroth explains. “We exhale the gas carbon dioxide, shed skin cells and hair, sneeze, cough, and so on. When we are outside, humans integrate into a complex web of life that manages these by-products. Seal a bunch of people up in a small artificial space, and you need some serious ventilation.”
Air filters can remove the majority of pollutants, but it is tough to rid a home of trace VOC elements. That’s where indoor plants come in. Several studies have shown that many indoor plants have an ability to filter out VOCs and other air pollutants.
Enroth adds, “It is believed that most of these air pollutants are filtered out as part of the plant’s photosynthesis activities. The air cleansing process is ongoing, so long as the plant is growing and healthy.”
An ongoing study examined five common houseplants and their efficiency at extracting VOCs from the air. It was found that dracaena was the most effective houseplant at absorbing acetone, a commonly used VOC found in products like nail polish remover. However, bromeliads performed best in the removal of six of the eight VOCs tested in the study.
Despite these results, other researchers are casting doubt on the effectiveness of indoor plants in removing pollutants. Earlier research on indoor plants involved small sealed chambers. Critics point out that when these studies are scaled up to the size of an average 1,500-square foot home, it would take 680 plants to clean the air.
Another problem is the amount of VOCs indoor plants are exposed to in a home or office. In one study, it was found that some homes contained up to 180 different airborne compounds. These chemicals are present in various concentrations and mix and interact in a nearly infinite number of ways, but most of the published research focuses on about a dozen different VOCs.
Does this mean you should toss your pothos in the compost?
“Of course not,” Enroth says. “Houseplants have routinely been proven to improve our psychological well-being. Those living or working in buildings like hospitals, extended care facilities, offices, and single- or multi-family buildings report better productivity, learning, and reduced anxiety and depression when indoor plants are present.
“What’s needed is more research on the effects of houseplants in homes and workplaces,” Enroth explains. “We know indoor plants assist in air cleansing; we just don’t know to what extent. Until that research becomes published, all gardeners agree: the world is a better place with more plants. So keep your rubber tree, spider plant, and dracaena. In fact, consider adding more indoor plants to your living and work environments.”
For more information on indoor plant maintenance, contact your local Extension office.
Garden tool care
URBANA, Ill. – After the garden is cleaned up and put to bed for the winter, it is time to give your tools some attention. University of Illinois Extension educator Jennifer Fishburn says that garden tools should be cleaned, sharpened, and hung in the correct place after every use, but admits that does not always happen.
“I think most gardeners are like myself,” Fishburn states. “Use the tool and be happy that it ended up in the shed and not lying in the yard.”
Quality garden tools that are properly cared for will last for a long time. Not only will properly maintained tools last longer, but clean, sharp blades will make garden work easier. In addition, cleaning tools removes disease inoculum that can be in soil and plant debris left on the tool.
Before storing tools for the winter, first remove soil and debris. Use a strong spray of water, wire brush, or putty knife to remove caked on soil. Remove small soil particles and rust spots with sandpaper or steel wool. Lubricate tool pivot points and springs with machine oil.
Sharpen larger tools such as hoes and shovels with a #10 bastard mill file or power drill with a coarse grinding disk or wheel. “To prepare for sharpening, place the tool in a vice, wear a pair of leather gloves and don’t forget your safety glasses,” Fishburn says. The cutting edge should be sharpened to maintain the same angle as the original bevel. Start with the top edge of the tool, file away from you, and only file one way, maintaining a 45-degree angle. File the opposite side lightly to remove metal burrs. Finally wipe or spray metal parts with a petroleum-based lubricant and rust-inhibitor such as WD-40.
“If you haven’t sharpened a tool before, it takes practice. If you regularly file your tools, this job will be much easier,” Fishburn adds.
Now that the metal parts are clean, the handle needs some attention. Fiberglass handles simply need to be washed and dried. To prevent splinters, sand rough spots on wooden handles with a fine to medium sandpaper. Replace weak or broken handles. Most hardware stores carry replacement handles. Remove dust and rub linseed oil into wooden handles. Let it soak in. Apply until it doesn’t absorb into the wood any more, then dry off any remaining oil. Tighten nuts, bolts, and screws. Replace them if they are worn or rusty. Last but not least, apply a band of bright colored paint or tape to the handle. This will help you find tools that have been left out in the yard or in your neighbor’s garage.
Bladed tools such as pruners should be disinfected after each use with rubbing alcohol or a 10 percent bleach/water solution. Lubricate moving parts of clippers and pruning shears with oil yearly. Many pruners can be disassembled for sharpening. Use a whetstone to sharpen beveled blades and be sure to maintain the original shape of the bevel.
“Before disassembling, it is a good idea to take a picture of the item,” Fishburn suggests. “This will aid in reassembling the tool.”
Store tools indoors in a clean, dry area with blade ends off the ground. Hang tools or store blades upright.
“Don’t forget about chemical sprayers,” Fishburn says. “These should be cleaned after every use. Before storing for the winter, thoroughly wash and rinse all parts. Most chemical manufacturers recommend triple rinsing of sprayers. Check the owner’s manual for other maintenance suggestions such as applying oil to all moving parts. Hang the sprayer upside down until thoroughly dry.”
Garden hoses are often forgotten in the fall. Be sure to drain all water from the hose and store it in a dry location. In the winter, water left in plastic hoses will cause the hose to freeze and crack. Store hoses on hose reel supports or coil loosely.
Wheelbarrows, carts, and wagons should be thoroughly cleaned. Touch up paint-chipped surfaces with spray paint to prevent exposed steel from rusting.
Refer to the owner’s manual for specific instructions on cleaning and storing power equipment. Avoid costly mistakes such as storing a power washer in an outdoor shed. In general, power equipment such as lawn mowers, tillers, and chippers should be thoroughly cleaned. Remove caked-on soil, plant material, and grass clippings from equipment. Tighten loose screws and nuts. Sharpen blades.
If you don’t have the tools or know-how to sharpen mower blades or pruners, take them to a professional. It is best to do this in the fall when they aren’t as busy.
“Just think about how nice it will be next spring when you go to the garden shed or garage and find all you garden tools ready for use,” Fishburn says.
New research at Illinois could make ethanol production more efficient and economic
- The enzymes needed to convert corn starch to glucose fermented to ethanol by yeast can now be found in new corn and ‘superior yeast,’ reducing the total enzyme addition by more than 80 percent.
- Using a vacuum flashing process, removing ethanol from the tank as it is produced insures yeast health and allows complete fermentation of corn solids up to 40 percent.
- Using high solids in the slurry reduces the amount of water needed as well as the amount of energy required to remove the water.
URBANA - New research at the Integrated Bioprocessing Research Laboratory (IBRL) on the University of Illinois Urbana-Champaign campus could significantly change ethanol production by lowering operating costs and simplifying the dry grind process.
“There are currently more than 200 dry grind plants that are processing corn to produce ethanol,” says Vijay Singh, director of IBRL and a professor in agricultural and biological engineering. “The dry grind process requires two different enzymes to convert corn starch to glucose, which is further fermented to ethanol by yeast.”
Singh says that process has been simplified by combined use and optimization of three new technologies. “A new corn developed by transgenic technology, known as amylase corn, produces one of these enzymes in the grain itself, and a newly engineered ‘superior yeast’ provides the second enzyme, as well as fermenting the glucose.
“There is a high expression level of the first enzyme, α-amylase, in the new corn, so only a small amount [15 percent was tested in these studies] of this corn is required to be mixed with conventional dent corn,” Singh notes. “The superior yeast provides the second enzyme, glucoamylase, and also provides an alternate metabolic pathway to reduce by-product formation during fermentation. Combined use of this corn and superior yeast can reduce the total enzyme addition by more than 80 percent.”
Another approach to improve the dry grind process is to use high solids in the plant. However, according to Singh, high solid concentrations leads to high ethanol build-up in the tank. “High ethanol affects the yeast viability and inhibits its fermentation performance, so we have added a third technology to the process. We remove the ethanol as it is being produced, using a vacuum flashing process that is patented technology from the University of Illinois. Only a couple of vacuum cycles of 1 to 1.5 hours can bring the ethanol concentration below the inhibitory levels without affecting yeast health and allow complete fermentation of corn solids up to 40 percent,” says Singh.
Deepak Kumar, a postdoctoral research associate in agricultural and biological engineering, says because the dry grind process uses a significant amount of water, using more solid material in the slurry - 40 percent as opposed to 30-35 percent - means less water going into the process. “When ethanol is produced, it is in a very dilute solution. You have a small amount of ethanol and a large amount of water,” says Kumar. “We cut down the water use by pushing high solids. When we reduce the amount of water, we also reduce the amount of energy required to remove the water.”
Singh believes this new research has the potential to improve the economics and process efficiencies and simplify the dry grind process. “By developing highly optimized technologies, we will benefit the entire dry grind industry,” he concludes.
Singh and Kumar received the 2016 Bioenergy Society of Singapore (BESS) Achievement Award for their work, in particular their paper “Dry-grind Processing using Amylase Corn and Superior Yeast to Reduce the Exogenous Enzyme Requirements in Bioethanol Production.” This award recognizes the importance of research on bio-energy and bio-based chemicals and was given to Singh and Kumar for their contributions to biofuels research. The paper has been published in Biotechnology for Biofuels, and the full text can be found online at http://bit.ly/2f4JFe3.
Grow tillandsias for the holiday season
URBANA, Ill. – Plant enthusiasts should check out tillandsia this holiday season, according to University of Illinois Extension educator Kelly Allsup.
“Even if you describe yourself as a brown thumb and are allergic to soil, you are going to love growing these super easy plants. The strappy tillandsia plants come in different sizes, textures, and colors and you are sure to find one to fit your holiday décor,” Allsup says.
Tillandsia is a type of epiphyte or “air plant.” In the wild, they use their minimal root system to attach themselves to trees and rocks, absorbing moisture and nutrients through small scales on their leaves. These scales give the plants their unique silver or gray appearance. “Air plants resemble a little octopus with their spreading tentacles,” Allsup says.
“They have been made popular as a houseplant and generally are easy to care for,” Allsup notes. “They enjoy indirect sun within the home or a shadier location if placed outside. Watering is critical. We recommend watering tillandsia once per week by submerging the entire plant in a bowl for 30 minutes to 2 hours. Allow them to dry a couple of hours before putting back into an enclosed environment. Misting can be done once or twice a week depending on the season.”
Tillandsia flowers range from white to bold orange, red, purple, or pink. Blossoms can quickly fade away or persist for several months. The flowers are long, tubular to funnel shaped, with showy floral parts. If they do not bloom, this may be an indication of insufficient light.
Allsup explains that there are two main types of tillandsias. “Some are gray and some are green. The gray kinds are native to tropical forests where long droughts are common. Their gray leaves reflect sunlight and conserve moisture. These can be mounted and grown in bright filtered light. Green-leaved tillandsias are native to rainy, humid tropical forests and are grown best in less light inside containers to keep them moist. Our Illinois winter homes are most appropriate for the gray kinds.”
Allsup recommends the following tillandsias for Illinois:
- Tillandsia caput-medusae has silvery twisty leaves, a swollen base, and a red flower stalk.
- Tillandsia plumosa boasts silvery leaves and can be grown on rocks or limbs.
- Tillandsia utriculata v. pringleyi has delicate thin silver leaves with a flowering stalk that is red to orange or pink.
Tillandsias can be displayed in a variety of artistic ways. For example, Allsup recommends creating a unique wreath by using the formed grapevine wreaths found in craft stores as a base. “Glue a variety of tillandsias, either in on one part of the wreath for an asymmetrical effect or throughout and then add small pine cones, colorful mosses, or miniature festive decorations,” she says.
“Or create a tillandsia landscape in a lantern, square glass vase, or under a cloche,” Allsup suggests. “Fill it with moss or aquarium gravel for a base, place in tillandsias, and adorn with pinecones, miniature décor, and driftwood. You could also place them in wine glasses and line them up along the center of the holiday table.
“For a unique gift,” Allsup adds, “place tillandsia in a clear plastic or glass ornament with colorful moss, or glue tillandsia to a wine cork or crystal.”