Leading the research will be Amy Millmier Schmidt, assistant professor in biological systems engineering and animal science, and Rick Koelsch, professor in biological systems engineering and animal science. The project is designed to provide natural resource benefits to Nebraska through increased utilization of livestock manure and cedar mulch among crop farmers.
"When manure is applied to cropland at agronomic rates using recommended best management practices, it provides agronomic, soil health, and environmental benefits," said Schmidt.
As the management of eastern red cedar trees has become a critical issue in many parts of the state, Schmidt and others have been studying practices that utilize the biomass created during forest management activities in ways that add value to this product.
"Combining wood chips with manure prior to land application could provide a market for the woody biomass generated during tree management activities and help offset the cost that landowners bear for tree removal," she said.
The team's on-farm research to date has demonstrated that manure-mulch mixtures improve soil characteristics without negatively impacting crop productivity. This new award will allow an expanded project team to demonstrate the practice more widely throughout the state, complete an economic analysis of the practice, and engage high school students in educational experiences related to soil health, conservation and cedar tree management. It will also introduce the students to on-farm research for evaluating a proposed practice change.
"On-farm research is at the core of extension and research programs at land-grant universities like Nebraska," said Koelsch. "Giving high school students hands-on experience evaluating a practice to understand how it impacts farm profitability is a unique way to improve science literacy, critical thinking skills, and interest in agricultural careers."
Outreach activities will focus on improving understanding among crop farmers of the benefits these amendments provide and motivating implementation of this new practice. The long-term goal of the project is to improve soil health properties for Nebraska soils, reduce nutrient losses to Nebraska water resources, and reduce eastern red cedar tree encroachment on Nebraska's pasture and grassland resources.
The project is one of the 105 projects receiving $18,301,819 in grant awards from the Nebraska Environmental Trust this year. The Nebraska Legislature created the Nebraska Environmental Trust in 1992. Using revenue from the Nebraska Lottery, the Trust has provided over $289 million in grants to over 2,000 projects across the state.
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Working with Muddy River Technologies of Delta, B.C., researchers at Langara College are seeking a cost effective way to prevent soil degradation and water contamination by removing phosphorus, nitrogen and other byproducts from animal manure.
The Fraser Valley is home to about 500 dairies, and the high amounts of slurry cause environmental and economic problems. Farmers do not have enough land to dispose of it, and they cannot expand because of the limitations placed on them by excess manure, said Langara researcher Kelly Sveinson.
This spring the college received $90,000 from the B.C. Innovation Council Ignite Award to support the project involving Sveinson, chemist Todd Stuckless and Rob Stephenson, chief technical officer of Muddy River Technologies, which works on water and waste treatments.
The project involves removing phosphates from manure using an electrochemical process similar to that used in environmental cleanups. The second step is to use a biochar carbon filter to capture ammonia that can be released as nitrogen. Ultimately those products could go back on the land as fertilizer. | READ MORE
It also coincided with the launch of a new, four-year effort by Dane County, called Suck the Muck, designed to literally suck a century's-worth of phosphorus from 33-miles of streams that feed the county's lakes.
Phosphorus, a nutrient found in the manure applied to agricultural fields, makes its way to Wisconsin waters (and waterways elsewhere) in runoff following rain storms. When the weather is warm, it can lead to the foul-smelling water and toxic algae blooms that plague lakes like Mendota, which is situated in an agricultural landscape.
This runoff may be getting worse, according to a recent study from researchers with the Water Sustainability and Climate Project at the University of Wisconsin–Madison. With a changing climate, the frequency of high-intensity rain events is on the rise. These storms bring heavy rains over a short period of time and exacerbate phosphorus runoff from manure-covered agricultural fields, more so than scientists expected.
"Both things are bad for water quality – too much manure is bad and too many intense storms are bad, too," says lead author of the study in Environmental Research Letters, Melissa Motew. "This is a story about how one problem really compounds another problem."
Indeed, the Lake Mendota algal bloom came on the heels of the second-wettest May in Madison's recorded history, and its eighth warmest. The National Weather Service reported that May 2018 was the wettest on record for the contiguous United States.
But Motew didn't start out asking how heavy storms and manure interact synergistically to affect water quality. It was while studying legacy phosphorus in soils – the accumulation of the nutrient over time – that she and the research team noticed something interesting in the data.
"We knew that heavy rain transports a lot of phosphorus off of a field and in 2014, (co-author Stephen Carpenter, emeritus professor and director of CFL) found that a relatively small number of rain events each year were delivering the majority of phosphorus to the lakes," she explains. "We happened to notice that it seemed like when we had periods of heavy rainfall we were seeing worse water quality than we expected. It prompted us to set up this study."
Climate change is bringing more intense rainfall across the U.S., particularly in the Midwest and Northeast. The 2014 study from Carpenter and colleagues showed that 74 percent of the phosphorus load in Lake Mendota is now delivered across just 29 days each year, and a 2016 study from scientists at Marylhurst University in Oregon and UW–Madison showed that annual precipitation in the Yahara watershed, which includes Lake Mendota, increased by 2.1 mm each year between 1930 and 2010.
This amounts to an increase of about seven inches of additional rain today, Motew explains. That same study also showed that while the frequency of large storm events in the region averaged 9.5 events per decade between 1930 and 1990, between 1991 and 2010, the number of large storm events nearly doubled, reaching 18 events per decade.
Using simulation models, Motew and the study team asked how more extreme rain events might interact with manure-and-fertilizer phosphorus supply on croplands to affect runoff at the level of an individual lake and the streams that feed it. That is, what happens when a given amount of rain falls on a field over the course of two hours instead of 24 hours?
"The model lets us scale up and make interesting observations from the scale of one field to the entire watershed," she says. "Models let us home in and study the process of how phosphorus moves in great detail."
Using two 60-year climate scenarios, one which assumed daily precipitation, maximum and minimum temperatures, wind speeds, relative humidity and solar radiation similar to current mean annual values in Madison, and another assuming more extreme rain events, Motew's model explored what happens to phosphorus concentrations in Lake Mendota and its tributary streams under low- and high-intensity precipitation conditions.
It took into account the real-life practices of farmers in the watershed – including their typical fertilizer and manure applications and tillage practices, the amount of phosphorus already stored in the surface layers of the soil, and the composition of the land around Lake Mendota. More than half of the land surrounding it is agricultural.
Motew found that dissolved phosphorus – the kind found in manure, as compared to other fertilizers and that found in soil – combined synergistically with heavy rain events to increase the amount of phosphorus running off into Lake Mendota and its streams.
"This puts us at even greater risk of worsening water quality," says Christopher Kucharik, study co-author and Motew's former graduate advisor. "This result also has wide-reaching implications because the synergistic relationship will likely be present in many agricultural watersheds around the world, where livestock and surface water co-exist."
Phosphorus is a critical nutrient for living organisms like crops. But what it does on land, it also does in water: encourages growth of organisms like plants and algae. When they die, these organisms fall to the bottom of an affected waterway, decomposing and consuming oxygen. This kills wildlife and encourages the growth of cyanobacteria, the organism behind toxic algae blooms. In some parts of the country, it can lead to dead zones, like in the Gulf of Mexico.
Farmers in Dane County and elsewhere are already applying less manure and doing so more precisely, Motew says, and she is hopeful these strategies will help to reduce phosphorus runoff from their croplands.
Motew, who is now a research fellow at The Nature Conservancy, also thinks farmers should be a part of continuing efforts to improve water quality. "We need to partner more with farmers so we can not only improve our own research by using better data, but so we can work together and build on their ideas, too." she says. "They know the problems up-close-and-personal and can provide insights we haven't considered. We as scientists can help explore where those insights may lead."
Motew adds: "Farmers are key to solving the problem, even though they are frequently blamed. We all need to take responsibility for our food system and find ways to support farmers in better manure management."
The study was supported by the National Science Foundation (grant numbers DEB-1038759 and DEB-1440297).
Anaerobic digesters are seen as a popular solution to wastewater treatment as they offer the potential for producing green energy and associated products.
Anaerobic digestion uses a series of biological micro-organism processes to break down wastewater material to produce biogas, which can then be combusted to generate electricity and heat, or can be further processed into renewable natural gas or transportation fuels. Dewatered material can also be used for compost. | READ MORE
Supported by a $250,000 appropriation from the Budget Act of 2017, the research will focus on understanding the differences in methane emissions from large and small dairies.
Researchers will also examine cost-saving techniques, evaluate emerging technologies, and investigate the economic impacts of methane regulations on California dairies.
The research will contribute to the Small Dairy Climate Action Plan which is required as part of the 2017-18 Budget Act (Item 8570-101-3228 (1) (b)). For more details on the awarded project, please visit www.cdfa.ca.gov/oefi/research/
But still, livestock are saddled with an outsized share of the blame for climate change. And if that misunderstanding persists, and pushes policymakers to force a societal shift from meat-eating, it could lead to disaster, says Ryan Katz-Rosene at the University of Ottawa’s school of political studies. READ MORE
Texas A&M AgriLife Research and the U.S. Department of Agriculture-Agricultural Research Service are collaborating to analyze nitrous oxide and methane emissions from an area feedyard pen.
Dr. Ken Casey, AgriLife Research air quality engineer in Amarillo, and Dr. David Parker and Dr. Heidi Waldrip, USDA-ARS livestock nutrient management researchers at Bushland, spent the better part of a week sitting inside a feedyard pen just vacated by cattle.
The project is funded by USDA-ARS and AgriLife Research, with instrumentation used in the study partly supported by the Texas Cattle Feeders Association.
Using six automated chambers, more than 575 automated flux measurements were taken, as were 60 manual flux measurements from separate static chambers, to help monitor nitrous oxide and methane gas emissions.
Halfway through the experiment, a half-inch of water was applied to the pen surface within the measurement chamber bases to simulate a rainfall.
"We're looking to understand better what controls nitrous oxide and methane coming off feedlot pen surfaces," Casey said. "We're interested in the emissions of these gases because of their contribution to climate change. We want to improve the national emissions inventories as they pertain to greenhouse gases from feedyards in the Texas High Plains.
"Secondly, we are also very interested in obtaining a better mechanistic understanding of the evolution of these gases from the pen surfaces. What controls the release of these gases? If we are able to gain a better understanding of that, then we will potentially be able to provide advice to the industry about mitigation practices when it comes to pen management."
Casey said their testing demonstrated areas of the pen with shallower manure packs on the surface primarily emitted nitrous oxide, while two chambers sitting over deeper manure where the pen drain was located emitted almost no nitrous oxide, but were emitting methane.
"We are trying to understand the interplay of those two gases, because the processes that are producing them are related," he said.
The different factors that influence the creation and release of the gases include temperature, moisture content and the amount of manure on the pen surface, Casey said.
"By understanding how those factors play together in the production of those gases, we can develop a greater understanding and potentially develop mitigation strategies," he said.
"However, it's complicated, because a strategy that reduces one emission may in fact increase the other. So our understanding of the production of these gases and the environmental factors that influence them are important."
During the study, gas samples were collected twice a day from the static chambers and then taken to Casey's air quality lab to be analyzed on a gas chromatograph. Six automated chambers took measurements each hour, around the clock. The automated chambers were linked through a multiplexer to automated nitrous oxide and methane analyzers.
"We know emissions are influenced by temperature, and by taking diurnal measurements, we can understand the variability throughout the day and night, as well as that of the effects of moisture."
The week of measurements is only part of ongoing research being conducted by Casey and Parker. Casey said the results will be reported to the industry, as well as in various journals along the way, and will be used for extended air quality research.
Parker said their research is also relevant to manure quality.
"Not only is this research important for greenhouse gas emissions, but through this and ongoing laboratory studies, we are learning more about nutrient transformations and water losses from the feedyard surface," he said.
When farmers repurpose the animals' manure as fertilizer or bedding, traces of the medicines leach into the environment, raising concerns that agriculture may be contributing to the rise of antibiotic-resistant bacteria.
New research holds troublesome insights with regard to the scope of this problem.
According to a pair of new studies led by Diana Aga, PhD, Henry M. Woodburn Professor of Chemistry in the University at Buffalo College of Arts and Sciences, two of the most elite waste treatment systems available today on farms do not fully remove antibiotics from manure.
Both technologies — advanced anaerobic digestion and reverse osmosis filtration — leave behind concerning levels of antibiotic residues, which can include both the drugs themselves and molecules that the drugs break down into.
In addition, the study uncovered new findings about solid excrement, which is often filtered out from raw, wet manure before the treatment technologies are implemented.
Researchers found that this solid matter may contain higher concentrations of antibiotics than unprocessed manure, a discovery that is particularly disturbing because this material is often released into the environment when it's used as animal bedding or sold as fertilizer.
"We were hoping that these advanced treatment technologies could remove antibiotics. As it turns out, they were not as effective as we thought they could be," Aga says.
She does offer some hope, however: "On the positive side, I think that a multistep process that also includes composting at the end of the system could significantly reduce the levels of antibiotics. Our earlier studies on poultry litter demonstrated that up to 70 percent reduction in antibiotics called ionophores can be achieved after 150 days of composting. Testing this hypothesis on dairy farm manure is the next phase of our project, and we are seeing some positive results."
The research on reverse osmosis filtration was published online in January in the journal Chemosphere. The study on advanced anaerobic digestion — a collaboration between UB and Virginia Tech — appeared online in March in the journal Environmental Pollution.
Waste treatment systems are not designed to remove antibiotics
According to the U.S. Food and Drug Administration, more than 30 million pounds of antibiotics approved for use in food-producing livestock were sold or distributed in the United States in 2016. And these are just a fraction of the total antibiotics used annually around the world in humans and animals.
Though the new research focuses on dairy farms, the findings point to a larger problem.
"Neither of the treatment systems we studied was designed to remove antibiotics from waste as the primary goal," Aga says. "Advanced anaerobic digestion is used to reduce odors and produce biogas, and reverse osmosis is used to recycle water. They were not meant to address removal of antibiotic compounds.
"This problem is not limited to agriculture: Waste treatment systems today, including those designed to handle municipal wastewater, hospital wastes and even waste from antibiotic manufacturing industries, do not have treatment of antibiotics in mind. This is an extremely important global issue because the rise of antibiotic resistance in the environment is unprecedented. We need to start thinking about this if we want to prevent the continued spread of resistance in the environment."
Aga is a proponent of the "One Health" approach to fighting antimicrobial resistance, which encourages experts working in hospitals, agriculture and other sectors related to both human and animal health to work together, as humans and animals are often treated with the same or similar antibiotics.
Aga was an invited presenter at an international forum last week on the latest research about antimicrobial resistance. The event, in Vancouver, Canada, was co-chaired by representatives of the UK Science and Innovation Network, Wellcome Trust and U.S. Centers for Disease Control and Prevention.
To conduct the research, scientists visited two dairy farms in Upstate New York.
Both facilities extract much of the solid matter from cow manure before subjecting the remaining sludge to high-tech waste management techniques. To process the remaining goop, one farm uses advanced anaerobic digestion, which employs microorganisms and pasteurization to break down and convert organic matter into products that include biogas, while the other farm uses reverse osmosis, which passes the slurry through a series of membranes to purify water.
Both technologies reduced antibiotic residues in liquid manure, but did little to cut down levels in the remaining solid matter. This is particularly worrisome as the research also revealed that antibiotic compounds tend to migrate from the liquid parts of the manure into the solids during treatment, making it arguably more important to treat than the latter.
The concern over solid excrement is heightened by the fact that the treatment techniques are implemented only after most solids are already separated from the raw manure, meaning that the bulk of the solid matter may go untreated.
Some key findings from each study:
The research on advanced anaerobic digestion examined a popular class of antibiotics called tetracyclines, finding that these drugs and their breakdown products migrated from the fluid part of the sludge into the solid part during treatment. At the end of the process, the solids contained higher levels of tetracycline antibiotics than the original raw manure. The study also found that both the liquid and solid parts of the sludge contained genes that confer resistance to these antibiotics.
The study on reverse osmosis looked at how well this water purification technique removed synthetic antimicrobials called ionophores, which are used to promote growth in dairy cows and to treat coccidiosis, a costly, parasitic disease in the cattle industry that affects mostly young calves.
The research found that reverse osmosis effectively filtered ionophores from the liquid portion of manure. However, low levels of the drugs persisted in "purified" water after treatment due to the deterioration of membranes used in the filtration process. Also, solid matter extracted from the water during reverse osmosis still harbored high levels of ionophores. Finally, the study found that prior to treatment, many of the ionophores appear to have already migrated into the solid part of the raw manure that is removed before the reverse osmosis even begins.
"Both of the systems we studied are a good first step in reducing the spread of antibiotics and potentially reduce resistance in the environment, but our study shows that more must be done," Aga says. "We need to look at different waste management practices that, maybe in combination, could reduce the spread of antibiotic compounds and resistance in the environment."
Aga points to composting as one area to explore. Her team is studying how advanced anaerobic digestion can be used in conjunction with composting of solid materials to remove antibiotics and their breakdown products from manure. The preliminary results of the research, not yet published, are promising, Aga says.
This uncertainty increases the risk of over-applying or under-applying nutrients to the field.
The risk is greatest with nitrogen (N), which can easily move out of manure during storage and is a source of drinking water concerns. However, there are ways that producers can lower that risk. One of those ways is by getting manure tested.
Studies from Minnesota and elsewhere have shown how important it is to get manure tested rather than relying on published book nutrient values, says Gregory Klinger, Extension educator for the University of Minnesota.
Book values suggest a specific nitrogen credit for specific manure types. They are useful for planning where to spread your manure, but can lead to over- or under-application of nutrients if used as the basis for actual application rates.
Manure nitrogen content is highly variable. Consider the case of liquid dairy manure, which has book values of 31 or 32 lbs N/1,000 gallons in Minnesota. Different studies on lab-tested dairy manure have found that individual manure N contents are typically anywhere from 20 to 40 percent higher or lower than these book values.
With a book value of 32 lbs N/1,000 gallons, the nitrogen in your dairy manure could be anywhere from 19.2 to 44.8 lbs/1,000 gallons. That creates quite a risk of over- or under-applying nitrogen.
Agitating and testing manure reduces that variability. While there is still variability in the results you get when you test manure, it is lower than relying on book values. Studies suggest 10 to 30 percent for unmixed manure, but as low as three to seven percent for well-mixed or agitated manure.
That means if you have 24 lbs N/1,000 gallons in your manure and it has been agitated and analyzed, you could reasonably expect the measured results to be from 22.3 to 25.7 lbs/1,000 gallons.
Much better than the 19.2 to 44.8 lbs/1000 gallons range you could expect without testing. While dairy manure is the example used here, these trends are true of other manure sources as well. Just by mixing and analyzing your manure, the risk of over- or under-applying nitrogen goes down immensely.
If you can't agitate your manure, try to take a number of subsamples from across the manure stockpile and mix them. Studies show that 15 to 25 subsamples will get the variation below 10 percent. For manure with an actual nitrogen concentration of 24 lbs N/ton, this would mean the N content reported by the lab would likely be 21.6 to 26.4 lbs/ton.
Many soil scientists in the Midwest have noted that when nitrogen application rates are less than 25 pounds above or below the best rate for a field, it usually has a negligible effect on yields and profitability, regardless of form.
That means that you don't need to hit a magical number that is best for your field, you just want to get within 25 pounds of that number. Testing manure will minimize how much uncertainty there is in manure N concentrations and help you hit that goal.
It was the first step in an ongoing study by dairy scientists, engineers and agronomists to see how a cow's breed and forage consumption affect the greenhouse gases generated by her gut and her manure.
The U.S. dairy industry has set a goal of reducing its greenhouse gas emissions by 25 percent by the year 2020, and UW–Madison researchers are helping identify strategies to accomplish that. | For the full story, CLICK HERE.
Screw Press Separation and Centrifugation are the two established technologies currently being investigated for their impact and effectiveness in removing, off farm, large quantities of solids from farm slurries and digestates i.e. feedstock.
Separation of feedstock produces a solids fraction containing a high proportion of phosphorus (P) which is more economical to transport off farm for both agricultural and non-agricultural purposes.
This is especially important for Northern Ireland, since oversupply of P to grassland has increased soil P levels beyond crop requirement optimum, leading to increased risk of P runoff to water courses and a negative impact on water quality. | For the full story, CLICK HERE
Iowa State University researchers have completed testing of a key component of a new concept for disposing of animal carcasses following a disease outbreak.
The research someday may help producers facing animal disease emergencies, such as in 2015 when avian influenza resulted in disposal of millions of chickens and turkeys in Iowa and other states.
Jacek Koziel, associate professor of agricultural and biosystems engineering, said animal health emergencies occur around the globe each year due, not only to disease, but also to hurricanes, flooding, fire and blizzards.
These incidents often require the disposal of numerous animal carcasses, usually accomplished via burial. In research published recently in the scientific journal Waste Management, Koziel and his team analyzed a method that could help livestock, poultry and egg producers deal more efficiently and safely with crises that lead to sudden increases in animal mortality.
Koziel and his team focused their research on improving on-farm burial, the method most commonly employed for large-scale carcass disposal due to its low cost and ability to quickly reduce the spread of airborne disease and foul odors. But emergency burial can contaminate nearby water resources with chemical and biological pollutants, and many locations in Iowa are considered unsuitable for such practices by the Iowa Department of Natural Resources.
Buried carcasses also decay slowly, sometimes delaying use of burial sites for crop production and other uses for years, Koziel said.
To overcome these problems, the researchers studied a hybrid disposal concept conceived at the National Institute of Animal Science in South Korea following a massive outbreak of foot-and-mouth disease in 2011.
The method combines burial with aerobic digestion, a method commonly used for treating sewage in which air is pumped through the content to speed decomposition.
The experiment also included burial trenches lined with flexible geomembranes like those used to prevent seepage from landfills and wastewater treatment ponds to protect water quality. The researchers then injected low levels of air into the bottom of the trench to accelerate carcass decomposition and treat the resulting liquid contaminants.
The experiment tested the performance of the aerobic component of the hybrid method in a lab using tanks containing whole chicken carcasses, water, and low levels of oxygen that occasionally dropped to zero as would be likely in emergency burial trenches.
Results of the study showed low levels of oxygen accelerated carcass decay significantly, reducing carcass mass by 95 percent within 13 weeks, while similar tests without air produced no noticeable decay. The air and water used for the experimental method create an ideal environment for bacteria to break down the carcasses quickly, a "shark tank," as Koziel described it.
Chemical contamination in the liquid waste met U.S. Environmental Protection Agency criteria for safe discharge to surface waters. The hybrid method also eliminated two common poultry pathogens, salmonella and staphylococcus. Aeration also reduced odorous gases sometimes associated with mass burial.
Koziel said the the encouraging laboratory results could pave the way for follow-up field studies that will include evaluation of alternative geomembrane liners, aeration system designs and components, and performance testing of the complete hybrid disposal system.
The research was supported by funding from the Korean Rural Development Administration.
Constructed wetland technology, uses sand, plants, and a network of pipes, to drain the moisture out of the sludge and dries the remaining solids into a concentrated and far more valuable fertiliser. | READ MORE
The researchers are presenting their results today at the 255th National Meeting & Exposition of the American Chemical Society (ACS). ACS, the world's largest scientific society, is holding the meeting here through Thursday. It features more than 13,000 presentations on a wide range of science topics.
The idea for the project germinated on Crete, where Alexander Bismarck, Ph.D., noticed goats munching on summer-dry grass in the small village where he was vacationing. "I realized what comes out in the end is partially digested plant matter, so there must be cellulose in there," he recalls.
"Animals eat low-grade biomass containing cellulose, chew it and expose it to enzymes and acid in their stomach, and then produce manure. Depending on the animal, up to 40 percent of that manure is cellulose, which is then easily accessible," Bismarck says. So, much less energy and fewer chemical treatments should be needed to turn this partially digested material into cellulose nanofibers, relative to starting with raw wood, he conjectured.
After working with goat manure, Bismarck, who is at the University of Vienna, Austria, his postdoc Andreas Mautner, Ph.D., and graduate students Nurul Ain Kamal and Kathrin Weiland moved on to dung from horses, cows and eventually elephants. The supply of raw material is substantial: Parks in Africa that are home to hundreds of elephants produce tons of dung every day, and enormous cattle farms in the U.S. and Europe yield mountains of manure, according to Mautner.
The researchers treat the manure with a sodium hydroxide solution. This partially removes lignin -- which can be used later as a fertilizer or fuel -- as well as other impurities, including proteins and dead cells. To fully remove lignin and to produce white pulp for making paper, the material has to be bleached with sodium hypochlorite. The purified cellulose requires little if any grinding to break it down into nanofibers in preparation for use in paper, in contrast to conventional methods.
"You need a lot of energy to grind wood down to make nanocellulose," Mautner says. But with manure as a starting material, "you can reduce the number of steps you need to perform, simply because the animal already chewed the plant and attacked it with acid and enzymes. You inexpensively produce a nanocellulose that has the same or even better properties than nanocellulose from wood, with lower energy and chemical consumption," he says.
The dung-derived nanopaper could be used in many applications, including as reinforcement for polymer composites or filters that can clean wastewater before it's discharged into the environment, Bismarck says. His team is working with an industrial consortium to further explore these possibilities. The nanopaper could also be used to write on, he says.
The researchers are also investigating whether the process can be made even more sustainable, by first producing biogas from manure and then extracting cellulose fibers from the residue. Biogas, which is mostly methane and carbon dioxide, can then be used as a fuel for generating electricity or heat.
"We need to know how feed affects methane production, but we also need to know how it affects other aspects of the farm operation, like daily gains in animals, milk production, and feed efficiency. Farmers want to help the environment, and they need to know what the trade-offs will be, which is why we took a holistic approach looking at the overall impacts," explains Dr. Karen Beauchemin, beef researcher from Agriculture and Agri-Food Canada (AAFC).
Researchers and farm system modellers from Agriculture and Agri-Food Canada, Agriculture Victoria (Australia), and the University of Melbourne, worked together to examine three feed supplements.
Methane inhibitor supplement 3-nitrooxypropanol (3NOP) could reduce costs and increase profits
3NOP is a promising commercial feed supplement that can be given to cattle to inhibit the enzyme methyl coenzyme M reductase – an enzyme responsible for creating methane in the animal's rumen (first stomach). After blocking the enzyme, 3NOP quickly breaks down in the animal's rumen to simple compounds that are already present in nature.
AAFC's Dr. Beauchemin studied the short- and long-term impacts of feeding 3NOP to beef cattle and shared her findings within the broader study.
"We now have clear evidence that 3NOP can have a long-term positive effect on reducing methane emissions and improving animal performance. We saw a 30-50% reduction in methane over a long period of time and a 3-5% improvement in feed efficiency," Beauchemin says.
Producing milk, gaining weight, and creating methane all take energy that a cow fuels by eating. Cattle eating a diet that contained the 3NOP supplement produced less methane. And, because there was less methane more energy could be used by the animal for growth. When using this supplement, cattle consumed less feed to gain a pound of body weight compared to control animals.
"What is also great is that the inhibitor worked just as effectively no matter what type of feed the cattle were eating," Beauchemin explains. "We don't know the actual market price of the supplement yet because it is still going through approvals for registration in Canada and the U.S. That will be important for farmers who want to calculate the cost-benefit of using 3NOP to reduce methane emissions from their cows and enhance profits."
The Story of Nitrate
Microorganisms in the cattle's rumen need nitrogen to be able to efficiently break down food for the animal to absorb. Nitrate is a form of non-protein nitrogen similar to that found in urea, a compound used in cattle diets. When nitrate is fed to cattle, it is converted to ammonia which is then used by the micro-organisms. During this process, nitrogen in the nitrate works like a powerful magnet that is able to hold onto and attract hydrogen. This leaves less hydrogen available in the rumen to attach to carbon to make methane, thus reducing the amount of methane produced.
Researchers in Canada found that adding nitrate to the diet of beef cattle reduces methane production by 20 percent in the short-term (up to three weeks), and after 16 weeks it still reduced methane up to 12 percent. In addition, feeding nitrate improved the gain-to-feed ratio. However, administering the correct dosage is extremely important, as too much nitrate can make an animal ill. So it is recommended this method should be used with care and caution.
Dr. Richard Eckard, a researcher from the University of Melbourne explained "I understand that in Canada, most forages are not that low in protein. But in the rangelands of northern Australia, the protein content in the forage is extremely low. It is possible that adding nitrate to Australian cattle feed may be able to improve the feeding regime from the current use of urea, but it depends on the price."
To supplement or not supplement with wheat, corn, or barley?
In the short term, wheat effectively reduced methane production by 35 percent compared with corn or barley grain; but, over time cattle were able to adapt to the change in feed and the methane inhibitory effect disappeared. Essentially, after 10 weeks, methane production was the same for corn, barley, and wheat.
The study also showed genetic variation in cows where about 50 percent of the cows that were fed wheat remained low in their methane emissions, even for as long as 16 weeks. However, the other cows adapted to the wheat diet and had methane emissions similar to, or even greater than those fed diets containing either corn or barley. Based on genetics, some cows are more adaptable than others and, in the long-term, it is more difficult to reduce the amount of methane they produce.
For dairy cows, Dr. Peter Moate, Dairy Researcher with Agriculture Victoria, was particularly intrigued about the link between milk fat, yield and methane emissions.
"We found that feeding cows wheat increased milk yield but fat levels decreased. For the farmer, it really depends on what they want to achieve in order to say whether this makes sense economically," explained Moate. "Overall, feeding wheat didn't have the long-term ability to reduce methane emissions, so it really couldn't be recommended as a best practice to achieve this type of goal."
"Our better understanding of feeding regimes will make a difference for farmers, but more importantly this research has really helped us understand more precisely the volume of greenhouse gases (GHGs) the industry is producing under different feed regimes. This is powerful information for policy makers," stated Beauchemin.
This is particularly true for countries that have implemented or are thinking about putting a price on carbon or a carbon trading scheme in place to reduce GHG emissions.
"By adopting different farming methods to reduce GHGs, farmers may be able to sell these "carbon credits" for revenue. But the key is to prove that these farming methods work and warrant being officially recognized for carbon credits. This work is one step closer in this process" explains Beauchemin.
While this project has wrapped-up, the work has not ended. Researchers in both countries unanimously agree that they will continue to help farmers and the industry find solutions to reducing their carbon footprint.
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Manure Science ReviewWed Jul 25, 2018 @ 8:00AM - 05:00PM
Environmental protection division - Stakeholder meetingThu Aug 02, 2018 @10:00AM - 12:00PM
2018 North American Manure ExpoWed Aug 15, 2018 @ 8:00AM - 05:00PM
2018 Canada's Outdoor Farm ShowTue Sep 11, 2018 @ 8:00AM - 05:00PM
Farm Science Review 2018Tue Sep 18, 2018 @ 8:00AM - 05:00PM
U.S. Poultry & Egg Environmental Management SeminarThu Sep 20, 2018 @ 8:00AM - 05:00PM