Human security at risk as depletion of soil accelerates

Sarah Yang at the UC Berkeley News Center: Steadily and alarmingly, humans have been depleting Earth’s soil resources faster than the nutrients can be replenished. If this trajectory does not change, soil erosion, combined with the effects of climate change, will present a huge risk to global food security over the next century, warns a review paper authored by some of the top soil scientists in the country.

The paper singles out farming, which accelerates erosion and nutrient removal, as the primary game changer in soil health. “Ever since humans developed agriculture, we’ve been transforming the planet and throwing the soil’s nutrient cycle out of balance,” said the paper’s lead author, Ronald Amundson, a UC Berkeley professor of environmental science, policy and management. “Because the changes happen slowly, often taking two to three generations to be noticed, people are not cognizant of the geological transformation taking place.”

In the paper, published [May 7] in the journal Science, the authors say that soil erosion has accelerated since the industrial revolution, and we’re now entering a period when the ability of soil, “the living epidermis of the planet,” to support the growth of our food supply is plateauing. The publication comes nearly two weeks ahead of the Global Soil Security Symposium at Texas A&M University, a meeting held as part of the declaration of 2015 as the International Year of Soils by the United Nations.

The authors identify the supply of fertilizer as one of the key threats to future soil security. Farmers use three essential nutrients to fertilize their crops: nitrogen, potassium and phosphorous. The paper credits the discovery of synthetic nitrogen production in the early 1900s for significantly increasing crop yields, which in turn supported dramatic growths in global population. Because the process of synthesizing nitrogen is energy-intensive, its supply is dependent on fossil fuels.

...Another threat to soil security relates to its role as a mass reservoir for carbon. Left unperturbed, soil can hold onto its stores of carbon for hundreds to thousands of years. The most recent estimates suggest that up to 2,300 gigatons of carbon are stored in the top three meters of the Earth’s soil – more carbon than in all the world’s plants and atmosphere combined. One gigaton is equal to a billion tons.

...One proposal is to stop discarding nutrients captured in waste treatment facilities. Currently, phosphorous and potassium are concentrated into solid waste rather than cycled back into the soil. Additionally, more efficient management is needed to curtail losses from soil. Excess nitrogen, for example, is considered a pollutant, with the runoff sapping oxygen from the nation’s waterways, suffocating aquatic life and creating dead zones in coastal margins...

A South Korean combine in 1976

More food, low pollution effort gains traction

A press release from the University of Maryland Center for Environmental Science: Nitrogen fertilizers make it possible to feed more people in the world than ever before. However, too much of it can also harm the environment. Professor Eric Davidson, director of the UMCES Appalachian Laboratory, has been leading a group of scientists, economists, social scientists, and agriculture experts in figuring out how to produce more food while lowering pollution at the same time. He calls it a “Mo Fo Lo Po”: more food, low pollution.

“The main objective is to produce abundant, nutritious, and affordable food and give farmers a chance to make a living, but do all of this while minimizing pollution of the environment,” said Davidson, whose research career has focused on how human changes to the land affect carbon and nitrogen in soil, water, and air.

Averaged globally, about half of the fertilizer nitrogen applied to farms is typically removed with the crops, while the other half either remains in the soil or is lost from the farmers’ fields. Knowledge and techniques already exist to make agriculture more productive and environmentally sustainable at the same time, yet many economic and social barriers still stand in the way of widespread adoption of practices by farmers.

...“Our objective is to bring together communities of scientists and stakeholders who would otherwise be unlikely to get together to talk about nitrogen issues as it relates to food security, pollution, human health impacts, global warming, ozone destruction, and the list goes on,” he said.

Less than two years later, the group has produced a collection of papers in Journal of Environmental Quality, published this month. A special section on Nitrogen Use Efficiency, guest edited by Davidson, provides a closer look at the economic, social, and technical impediments to improving efficiency of nitrogen use in crop and animal farms....

Photo of wheat stalks by CSIRO, Wikimedia Commons, under the Creative Commons Attribution 3.0 Unported license

Satellite eyes on threat to US freshwater

A press release from NASA: NASA has joined forces with the U.S. Environmental Protection Agency, National Oceanic and Atmospheric Administration, and U.S. Geological Survey to transform satellite data designed to probe ocean biology into information that will help protect the American public from harmful freshwater algal blooms.

Algal blooms are a worldwide environmental problem causing human and animal health risks, fish kills, and taste and odor in drinking water. In the United States, the cost of freshwater degraded by harmful algal blooms is estimated at $64 million annually. In August 2014, officials in Toledo, Ohio, banned the use of drinking water supplied to more than 400,000 residents after it was contaminated by an algal bloom in Lake Erie.

The new $3.6 million, multi-agency effort will use ocean color satellite data to develop an early warning indicator for toxic and nuisance algal blooms in freshwater systems a
nd an information distribution system to aid expedient public health advisories.

“The vantage point of space not only contributes to a better understanding of our home planet, it helps improve lives around the world,” said NASA Administrator Charles Bolden. “We’re excited to be putting NASA’s expertise in space and scientific exploration to work protecting public health and safety.”

Ocean color satellite data from NASA’s Aqua, the USGS-NASA Landsat, and the European Space Agency’s Sentinel-2 and -3 are currently available to scientists, but are not routinely processed and produced in formats that help state and local environmental and water quality managers. Through this project, satellite data on harmful algal blooms developed by the partner agencies will be converted to a format that stakeholders can use through mobile devices and web portals.

“Observations from space-based instruments are an ideal way to tackle this type of public health hazard because of their global coverage and ability to provide detailed information on material in the water, including algal blooms,” said Paula Bontempi of the Earth Science Division at NASA Headquarters in Washington....

A toxic algae bloom in Lake Erie in 2011, viewed by a NASA satellite

Nutrient pollution damages streams in ways previously unknown, ecologists find

Beth Gavriles in UGA Today: An important food resource has been disappearing from streams without anyone noticing until now. In a new study published March 6 in the journal Science, a team of researchers led by University of Georgia ecologists reports that nutrient pollution causes a significant loss of forest-derived carbon from stream ecosystems, reducing the ability of streams to support aquatic life.

The findings show that the in-stream residence time of carbon from leaves, twigs and other forest matter, which provide much of the energy that fuels stream food webs, is cut in half when moderate amounts of nitrogen and phosphorus are added to a stream. "This study shows how excess nutrients reduce stream health in a way that was previously unknown," said the study's lead author Amy D. Rosemond, an associate professor in the UGA Odum School of Ecology.

Stream food webs are based on carbon from two main sources. One is algae, which produce carbon through photosynthesis. Nutrient pollution has long been known to increase carbon production by algae, often causing nuisance and harmful algal blooms. The second source is leaves and bits of wood from streamside forests. This forest-derived carbon typically persists year-round, making it a staple food resource for stream organisms.

"Most people think of nitrogen and phosphorus pollution in streams as contributing to algae blooms," said Diane Pataki, program director in the National Science Foundation's Division of Environmental Biology, which funded the research. "But streams contain a lot of leaf litter, and this study shows that nutrient pollution can also stimulate carbon losses from streams by accelerating the breakdown of that litter. That helps us better understand how fertilizer runoff affects carbon transport and emissions from streams and rivers."...

Looking east toward Haystack Butte and Haystack Creek along the Going-to-the-Sun Road. The cut of the Going-to-the-Sun Road, a National Civil Engineering Landmark, is visible in the vegetation of the mountainside. Photo: David Restivo, NPS, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license

How much fertilizer is too much for the climate?

Michigan State University Today: Helping farmers around the globe apply more-precise amounts of nitrogen-based fertilizer can help combat climate change. In a new study published in this week’s Proceedings of the National Academy of Sciences, Michigan State University researchers provide an improved prediction of nitrogen fertilizer’s contribution to greenhouse gas emissions from agricultural fields.

The study uses data from around the world to show that emissions of nitrous oxide, a greenhouse gas produced in the soil following nitrogen addition, rise faster than previously expected when fertilizer rates exceed crop needs.

Nitrogen-based fertilizers spur greenhouse gas emissions by stimulating microbes in the soil to produce more nitrous oxide. Nitrous oxide is the third most important greenhouse gas, behind only carbon dioxide and methane, and also destroys stratospheric ozone. Agriculture accounts for around 80 percent of human-caused nitrous oxide emissions worldwide, which have increased substantially in recent years, primarily due to increased nitrogen fertilizer use.

“Our specific motivation is to learn where to best target agricultural efforts to slow global warming,” said Phil Robertson, director of MSU’s Kellogg Biological Station Long-term Ecological Research Program and senior author of the paper. “Agriculture accounts for 8 to 14 percent of all greenhouse gas production globally. We’re showing how farmers can help to reduce this number by applying nitrogen fertilizer more precisely.”

The production of nitrous oxide can be greatly reduced if the amount of fertilizer crops need is exactly the amount that’s applied to farmers’ fields. Simply put, when plant nitrogen needs are matched with the nitrogen that’s supplied, fertilizer has substantially less effect on greenhouse gas emission, Robertson said.

Iurii Shcherbak, lead author and MSU researcher, noted that the research also informs fertilizer practices in underfertilized areas such as sub-Saharan Africa. “Because nitrous oxide emissions won’t be accelerated by fertilizers until crop nitrogen needs are met, more nitrogen fertilizer can be added to underfertilized crops with little impact on emissions,” he said...

A corn field in Hungary, shot by Hyena, public domain

Study resolves controversy over nitrogen’s ocean “exit strategies”

Catherine Zandonella at the Office of the Dean for Research at Princeton University:
A decades-long debate over how nitrogen is removed from the ocean may now be settled by new findings from researchers at Princeton University and their collaborators at the University of Washington.

The debate centers on how nitrogen — one of the most important food sources for ocean life and a controller of atmospheric carbon dioxide — becomes converted to a form that can exit the ocean and return to the atmosphere where it is reused in the global nitrogen cycle.

Researchers have argued over which of two nitrogen-removal mechanisms, denitrification and anammox, is most important in the oceans. The question is not just a scientific curiosity, but has real world applications because one mechanism contributes more greenhouse gases to the atmosphere than the other.

“Nitrogen controls much of the productivity of the ocean,” said Andrew Babbin, first author of the study and a graduate student who works with Bess Ward, Princeton’s William J. Sinclair Professor of Geosciences. “Understanding nitrogen cycling is crucial to understanding the productivity of the oceans as well as the global climate,” he said.

In the new study, the researchers found that both of these nitrogen “exit strategies” are at work in the oceans, with denitrification mopping up about 70 percent of the nitrogen and anammox disposing of the rest.

...Essential for the Earth’s life and climate, nitrogen is an element that cycles between soils and the atmosphere and between the atmosphere and the ocean. Bacteria near the surface help shuttle nitrogen into the ocean food chain by converting or “fixing” atmospheric nitrogen into forms that phytoplankton can use.

Without this fixed nitrogen, phytoplankton could not absorb carbon dioxide from the air, a feat which is helping to check today’s rising carbon dioxide levels in the atmosphere. When these tiny marine algae die or are consumed by predators, their biomass sinks to the ocean interior where it becomes food for other types of bacteria....

Princeton University graduate student Andrew Babbin (left) prepares a seawater collection device known as a rosette. The team used samples of seawater to determine how nitrogen is removed from the oceans. (Research photos courtesy of A. Babbin)

Research clarifies health costs of air pollution from agriculture

A press release from NASA: Ammonia pollution from agricultural sources poses larger health costs than previously estimated, according to NASA-funded research.

Harvard University researchers Fabien Paulot and Daniel Jacob used computer models including a NASA model of chemical reactions in the atmosphere to better represent how ammonia interacts in the atmosphere to form harmful particulate matter. The improved simulation helped the scientists narrow in on the estimated health costs from air pollution associated with food produced for export – a growing sector of agriculture and a source of trade surplus.

"The 'cost' is an economic concept to measure how much people are willing to pay to avoid a risk," Paulot said. "This isused to quantify the cost for society but also to evaluate the benefits of mitigation."

The new research by Paulot and Jacob calculate the health cost associated with the ammonia emissions from agriculture exports to be $36 billion a year – equal to about half of the revenue generated by those same exports – or $100 per kilogram of ammonia. The study was published December 2013 in Environmental Science & Technology.

The new estimate is about double the current estimate by the U.S. Environmental Protection Agency, which suggests a cost of $47 per kilogram of ammonia. The scientists say the new estimate is on the high end of the spectrum, which reflects the need for more research into characterizing the relationship between agricultural ammonia emissions and the formation of the harmful fine particulate matter – a relationship that's not as straightforward as previous estimates assumed.

"The effect of ammonia on fine particulate is complex, and we believe that the models previously used in the United States to price ammonia emissions have not captured this well," Paulot said.

The map shows increase in annual mean surface concentration of particulate matter resulting from ammonia emissions associated with food export. Populated states in the Northeast and Great Lakes region, where particulate matter formation is promoted by upwind ammonia sources, carry most of the cost.

Study shows less snowpack will harm ecosystem

Newswise via Boston University: A new Boston University study shows that the consequences of milder winters – a smaller snowpack leaving the ground to freeze harder and longer – can have a negative impact on trees and water quality of nearby aquatic ecosystems far into the warmer growing season.

In a paper in the journal Global Change Biology, BU biology Prof. Pamela Templer and her co-authors show that soil freezing due to diminishing snowpack damages the roots of sugar maple trees and limits their ability to absorb essential nitrogen and other nutrients in the spring. This leads to greater run off of nitrogen into ground water and nearby streams, which could deteriorate water quality and trigger widespread harmful consequences to humans and the environment.

“Most people think that climate change means hot, sweltering summer months, but it affects the winter as well,” said ecologist Templer, currently on fellowship at Harvard University, noting that winter snowpack has been shrinking over the past 50 years due to climate change and is likely to continue diminishing over time.

Templer and her colleagues discovered that a thick layer of snow acts as an insulating blanket. When snowpack was shoveled off sections of New Hampshire’s Hubbard Brook Experimental Forest to simulate the effects of a warm winter, the soil was much colder – a much as 10 degrees less -- than when it was when covered with deep snow. This means the ground could be frozen solid longer into the spring.

Templer is following up her winter research with a new National Science Foundation funded project that uses warming cables in the ground to determine the combined effects of warmer winters and summer on the trees....

A NASA image of Kings Canyon National Park in the Sierras of California

Nitrogen-tracking tools for better crops and less pollution

The Carnegie Institution for Science: As every gardener knows, nitrogen is crucial for a plant’s growth. But nitrogen absorption is inefficient. This means that on the scale of food crops, adding significant levels of nitrogen to the soil through fertilizer presents a number of problems, particularly river and groundwater pollution. As a result, finding a way to improve nitrogen uptake in agricultural products could improve yields and decrease risks to environmental and human health.

Nitrogen is primarily taken up from the soil by the roots and assimilated by the plant to become part of DNA, proteins, and many other compounds. Uptake is controlled by a number of factors, including availability, demand, and the plant's energy status. But there is much about the transport proteins involved in the process that isn't understood.

New work from Carnegie's Cheng-Hsun Ho and Wolf Frommer developed tools that could help scientists observe the nitrogen-uptake process in real time and could lead to developments that improve agriculture and the environment. It will be published by eLife on March 11 and is already available online.

Frommer had previously developed technology to spy on transport protein activity by using fluorescent tags in a cell's DNA to monitor the structural rearrangements that a transporter undergoes as it moves its target molecule. They tailored this technology to five nitrogen transport targets to monitor the nitrogen uptake and assimilation process.

"We engineered these sensors to monitor the activity and regulation of suspected nitrogen transporters in living plant roots, which otherwise are impossible to study," Frommer said. "This suite of tools will vastly improve our understanding of the nitrogen-uptake process and will help to develop increased crop yields and decrease fertilizer-caused pollution."

Their method is applicable to any transporter from any organism, thereby enabling the otherwise exceptionally difficult analysis of transport processes in the tissues of plants and animals....

Image from the Carnegie Institution's website

Fertilizer nutrient imbalance to limit food production in Africa

A press release from the International Institute for Applied Systems Analysis: A growing imbalance between phosphorus and nitrogen fertilizer use in Africa could lead to crop yield reductions of nearly 30% by 2050, according to a new study from researchers at the International Institute for Applied Systems Analysis (IIASA).

Underuse of phosphorus-based fertilizers in Africa currently contributes to a growing yield gap—the difference between how much crops could produce in ideal circumstances compared to actual yields. This phosphorus-specific yield gap currently lies at around 10% for subsistence farmers, but will grow to 27% by 2050 if current trends continue, according to a study published today in the journal Global Change Biology.

“This research shows that the imbalance between nitrogen and phosphorus applications has the potential to further limit food production for a growing population in Africa” says Marijn van der Velde, a researcher now at the Joint Research Centre of the European Commission, who led the study while working at IIASA.

...“Farmers with limited money are more likely to buy and have access to cheaper nitrogen-based fertilizers,” says van der Velde. “While this might work in the short term, in the longer term it has a negative effect on crop growth as soil nutrients become more imbalanced.”

As farmers use fertilizers for their crops, nutrients such as nitrogen and phosphorus build up in the soil, providing a reserve of nutrients that plants need to grow. But fertilizer use remains very low in Africa, and to increase crop production, it is widely recognized that farmers must increase their fertilizer use. And while nitrogen-based fertilizer usage has begun to increase in Africa in the last 10 years, the application of phosphorus to cropland has not kept pace, leading to a growing imbalance between nitrogen and phosphorus levels in soil. The new study shows that increases in nitrogen and phosphorus inputs must happen in a way that provides crops with the balanced nutrient input they need....

An electron shell diagram of phosphorus, created by Pumbaa (original work by Greg Robson), Wikimedia Commons, under the Creative Commons Attribution-Share Alike 2.0 UK: England & Wales license 

Nitrogen deposition poses a threat to the diversity of Europe's forest vegetation

A press release from the Finnish Environment Institute: Unless nitrogen emissions are curbed, the diversity of plant communities in Europe's forests will decrease. Atmospheric nitrogen deposition has already changed the number and richness of forest floor vegetation species in European forests over the last 20–30 years. In particular, the coverage of plant species adapted to nutrient-poor conditions has reduced. However, levels of nitrogen deposition in Finnish forests remain small compared to Southern and Central Europe.

These results will be presented as part of international research published in the journal Global Change Biology. Researchers from the Finnish Environment Institute and the Finnish Forest Research Institute (Metla) participated in this research, which concludes that unless nitrogen emissions are curbed, the diversity of plant communities in Europe's forests will decrease. The work involved the examination of long-term changes in vascular plant communities within a 1 300 monitoring grid covering 28 forested areas in various parts of Europe.

The number and richness of forest floor vegetation species in European forests have changed over the last 20 to 30 years, due to wet and dry deposition of atmospheric nitrogen. In particular, low-nutrient or acidic habitats are sensitive to long-term nitrogen deposition. Among such habitats, coverage of species such as heather and may lily has been reduced in many areas, in which nitrogen deposition has exceeded a certain threshold value i.e. the critical nitrogen load.

The largest changes in vegetation have occur red in Southern and Central European forests. Although deposition has not yet markedly affected species numbers within plant communities, most new species spreading into forests during the monitoring period have been types that favour nitrogen.

...Although nitrogen deposition remains small in Northern Europe, even a slight rise in long-term deposition could change the competitive relationship of vascular plants by promoting the dissemination and growth of nitrogen-favouring species....

Species found in nutrient-poor habitats, such as heather, lingonberry, crowberry and lichens in particular are sensitive to nitrogen deposition. Photo Hannu Nousiainen, Metla.

Increasing toxicity of algal blooms tied to nutrient enrichment and climate change

Oregon State University News & Research Communications: Nutrient enrichment and climate change are posing yet another concern of growing importance – an apparent increase in the toxicity of some algal blooms in freshwater lakes and estuaries around the world, which threatens aquatic organisms, ecosystem health and human drinking water safety. As this nutrient enrichment, or “eutrophication” increases, so will the proportion of toxin-producing strains of cyanobacteria in harmful algal blooms, scientists said.

Researchers from Oregon State University and the University of North Carolina at Chapel Hill will outline recent findings in an analysis Friday in the journal Science. Cyanobacteria are some of the oldest microorganisms on Earth, dating back about 3.5 billion years to a time when the planet was void of oxygen and barren of most life. These bacteria are believed to have produced the oxygen that paved the way for terrestrial life to evolve. They are highly adaptive and persistent, researchers say, and today are once again adapting to new conditions in a way that threatens some of the life they originally made possible.

A particular concern is Microcystis sp., a near-ubiquitous cyanobacterium that thrives in warm, nutrient-rich and stagnant waters around the world. Like many cyanobacteria, it can regulate its position in the water column, and often forms green, paint-like scums near the surface.

In a high-light, oxidizing environment, microcystin-producing cyanobacteria have a survival advantage over other forms of cyanobacteria that are not toxic. Over time, they can displace the nontoxic strains, resulting in blooms that are increasingly toxic.

“Cyanobacteria are basically the cockroaches of the aquatic world,” said Timothy Otten, a postdoctoral scholar in the OSU College of Science and College of Agricultural Sciences, whose work has been supported by the National Science Foundation. “They're the uninvited guest that just won't leave.”...

A microcystis cousin of the cyanobacteria mentioned in this article, shot by T.Voekler, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Nitrogen fertilizer remains in soils and leaks towards groundwater for decades

Terra Daily via SPX: Nitrogen fertilizer applied to crops lingers in the soil and leaks out as nitrate for decades towards groundwater - "much longer than previously thought," scientists in France and at the University of Calgary say in a new study. Thirty years after synthetic nitrogen (N) fertilizer had been applied to crops in 1982, about 15 per cent of the fertilizer N still remained in soil organic matter, the scientists found.

After three decades, approximately 10 per cent of the fertilizer N had seeped through the soil towards the groundwater and will continue to leak in low amounts for at least another 50 years. The study was led by researcher Mathieu Sebilo at the Universite Pierre et Marie Currie in Paris, France, and by Bernhard Mayer in the U of C's Department of Geoscience, and included several research organizations in France.

Their paper, "Long-term fate of nitrate fertilizer in agricultural soils," was published this week in the Proceedings of the National Academy of Sciences of the United States of America. The findings show that losses of fertilizer N towards the groundwater occur at low rates but over many decades, says Mayer, U of C professor of geochemistry and head of the Applied Geochemistry Group.

That means it could take longer than previously thought to reduce nitrate contamination in groundwater, including in aquifers that supply drinking water in North America and elsewhere, he says. "There's a lot of fertilizer nitrogen that has accumulated in agricultural soils over the last few decades which will continue to leak as nitrate towards groundwater," Mayer says....

From Geoff Ruth's  High School Earth Science 1-13.pdf (page 493), Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Unregulated agricultural ammonia threatens national parks’ ecology

A press release on Harvard's website: Thirty-eight U.S. national parks are experiencing “accidental fertilization” at or above a critical threshold for ecological damage, according to a study published in the journal Atmospheric Chemistry and Physics and led by Harvard University researchers. Unless significant controls on ammonia emissions are introduced at a national level, they say, little improvement is likely between now and 2050.

The environmental scientists, experts in air quality, atmospheric chemistry, and ecology, have been studying the fate of nitrogen-based compounds that are blown into natural areas from power plants, automobile exhaust, and—increasingly—industrial agriculture. Nitrogen that finds its way into natural ecosystems can disrupt the cycling of nutrients in soil, promote algal overgrowth and lower the pH of water in aquatic environments, and ultimately decrease the number of species that can survive.

“The vast majority, 85 percent, of nitrogen deposition originates with human activities,” explains principal investigator Daniel J. Jacob, Vasco McCoy Family Professor of Atmospheric Chemistry and Environmental Engineering at the Harvard School of Engineering and Applied Sciences (SEAS). “It is fully within our power as a nation to reduce our impact.”

Existing air quality regulations and trends in clean energy technology are expected to reduce the amount of harmful nitrogen oxides (NOx) emitted by coal plants and cars over time. However, no government regulations currently limit the amount of ammonia (NH3) that enters the atmosphere through agricultural fertilization or manure from animal husbandry, which are now responsible for one-third of the anthropogenic nitrogen carried on air currents and deposited on land.

“Ammonia’s pretty volatile,” says Jacob. “When we apply fertilizer in the United States, only about 10 percent of the nitrogen makes it into the food. All the rest escapes, and most of it escapes through the atmosphere.”

...In many previous studies, environmental scientists have identified the nitrogen levels that would be ecologically harmful in various settings. The new Harvard-led study uses a high-resolution atmospheric model called GEOS-Chem to calculate nitrogen deposition rates across the contiguous United States, and compares those rates to the critical loads. The findings suggest that many parks may already be suffering....

A bear in Smoky Mountains National Park, National Park Service photo

Wetlands more cost-effective in nutrient removal, but multiple payments would be of uncertain value

Space Daily via SPX: Removing nitrogen from the environment "the natural way" by creating a wetland is a long-term, nutrient-removal solution, more cost effective than upgrading a wastewater treatment plant, but it isn't necessarily socially beneficial to offer landowners multiple payments for the environmental services that flow from such wetlands, according to a study conducted at the University of Illinois.

"In the areas we studied in Bureau County with small wastewater treatment plants (WWTPs), it was much cheaper to do pollution control by installing just a few wetlands than it was to have the WWTPs do the upgrades that would be necessary to achieve the same thing," said U of I environmental economist Amy Ando.

Bureau County was selected for the simulation because it is an area that has waterways with heavy nitrogen and phosphorus pollution, and it is a rural area of the state but with some population density and a couple of WWTPs.

"In some ways, it's a poster child for an environment where a program like this could work," Ando said. "There is enough farmland to put in some wetlands, but there are also enough people contributing to the WWTPs that are generating nutrients-so there are parties on both sides that could trade with each other."

The study analyzed the amount of land needed to reduce nitrogen pollution, data on the costs of actual wetland restorations, and other factors such as the opportunity costs to the landowner from no longer farming the new wetland area.

"Wastewater treatment plants can already remove nitrogen, but their current technology is only capable of removing them up to a point," Ando said. "If they wanted to do more nitrogen removal, they would have to make upgrades. The cost of phosphorus removal isn't high, but for nitrogen, the upgrades are pretty expensive."...

Kennekuk Marshes, Lake Vermillion, Illinois, shot by Huw Williams (Huwmanbeing), who has released it into the public domain

Tropical forest carbon absorption may hinge on an odd couple

Princeton University News: A unique housing arrangement between a specific group of tree species and a carbo-loading bacteria may determine how well tropical forests can absorb carbon dioxide from the atmosphere, according to a Princeton University-based study. The findings suggest that the role of tropical forests in offsetting the atmospheric buildup of carbon from fossil fuels depends on tree diversity, particularly in forests recovering from exploitation.

Tropical forests thrive on natural nitrogen fertilizer pumped into the soil by trees in the legume family, a diverse group that includes beans and peas, the researchers report in the journal Nature. The researchers studied second-growth forests in Panama that had been used for agriculture five to 300 years ago. The presence of legume trees ensured rapid forest growth in the first 12 years of recovery and thus a substantial carbon "sink," or carbon-storage capacity. Tracts of land that were pasture only 12 years before had already accumulated as much as 40 percent of the carbon found in fully mature forests. Legumes contributed more than half of the nitrogen needed to make that happen, the researchers reported.

These fledgling woodlands had the capacity to store 50 metric tons of carbon per hectare (2.47 acres), which equates to roughly 185 tons of carbon dioxide, or the exhaust of some 21,285 gallons of gasoline. That much fuel would take the average car in the United States more than half a million miles. Though the legumes' nitrogen fertilizer output waned in later years, the species nonetheless took up carbon at rates that were up to nine times faster than non-legume trees.

The legumes' secret is a process known as nitrogen fixation, carried out in concert with infectious bacteria known as rhizobia, which dwell in little pods inside the tree's roots known as root nodules. As a nutrient, nitrogen is essential for plant growth, but tropical soil is short on nitrogen and surprisingly non-nutritious for trees. Legumes use secretions to invite rhizobia living in the soil to infect their roots, and the bacteria signal back to initiate nodule growth. The rhizobia move into the root cells of the host plant and — in exchange for carbohydrates the tree produces by photosynthesis — convert nitrogen in the air into the fertilizer form that plants need. Excess nitrogen from the legume eventually creates a nitrogen cycle that benefits neighboring trees....

The diverse forest canopy on Barro Colorado Island, (Darien Jungle) Panama - Colombia, has provided ecologist Stephen Hubbell with years of data to test his controversial neutral theory of biodiversity and biogeography. Photos by Christian Ziegler, under the Creative Commons Attribution 2.5 Generic license

Climate change will upset vital ocean chemical cycles

University of East Anglia: New research from the University of East Anglia shows that rising ocean temperatures will upset natural cycles of carbon dioxide, nitrogen and phosphorous. Plankton plays an important role in the ocean’s carbon cycle by removing half of all CO2 from the atmosphere during photosynthesis and storing it deep under the sea – isolated from the atmosphere for centuries.

Findings published [September 8]in the journal Nature Climate Change reveal that water temperature has a direct impact on maintaining the delicate plankton ecosystem of our oceans. The new research means that ocean warming will impact plankton, and in turn drive a vicious cycle of climate change.

Researchers from UEA’s School of Environmental Sciences and the School of Computing Sciences investigated phytoplankton – microscopic plant-like organisms that rely on photosynthesis to reproduce and grow.

Lead researcher Dr Thomas Mock, said: “Phytoplankton, including micro-algae, are responsible for half of the carbon dioxide that is naturally removed from the atmosphere. As well as being vital to climate control, it also creates enough oxygen for every other breath we take, and forms the base of the food chain for fisheries so it is incredibly important for food security.

“Previous studies have shown that phytoplankton communities respond to global warming by changes in diversity and productivity. But with our study we show that warmer temperatures directly impact the chemical cycles in plankton, which has not been shown before.”...

Phytoplankton, image by Uwe Kils, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Scientists find large Gulf dead zone, but smaller than predicted

NOAA: NOAA-supported scientists found a large Gulf of Mexico oxygen-free or hypoxic “dead” zone, but not as large as had been predicted. Measuring 5,840 square miles, an area the size of Connecticut, the 2013 Gulf dead zone indicates nutrients from the Mississippi River watershed are continuing to affect the nation’s commercial and recreational marine resources in the Gulf.

“A near-record area was expected because of wet spring conditions in the Mississippi watershed and the resultant high river flows which deliver large amounts of nutrients,” said

Hypoxia is fueled by nutrient runoff from agricultural and other human activities in the watershed. These nutrients stimulate an overgrowth of algae that sinks, decomposes and consumes most of the oxygen needed to support life. Normally the low or no oxygen area is found closer to the Gulf floor as the decaying algae settle towards the bottom. This year researchers found many areas across the Gulf where oxygen conditions were severely low at the bottom and animals normally found at the seabed were swimming at the surface.

This is in contrast to 2012, when drought conditions resulted in the fourth smallest dead zones on record, measuring 2,889 square miles, an area slightly larger than Delaware. The largest previous dead zone was in 2002, encompassing 8,481 square miles. The smallest recorded dead zone measured 15 square miles in 1988. The average size of the dead zone over the past five years has been 5,176 square miles, more than twice the 1,900 square mile goal set by the Gulf of Mexico / Mississippi River Watershed Nutrient Task Force in 2001 and reaffirmed in 2008.

...“NOAA’s investment in the Gulf of Mexico continues to yield results that confirm the complex dynamics of hypoxia and provide managers and the public with accurate scientific information for managing and restoring the nation's valuable coastal resources,” said Robert Magnien, Ph.D., director of NOAA’s Center for Sponsored Coastal Ocean Research. “For those who depend upon and enjoy the abundant natural resources of the Gulf of Mexico, it is imperative that we intensify our efforts to reduce nutrient pollution before the ecosystem degrades any further.”...

Map showing the hypoxia area on the Louisiana Gulf of Mexico shelf in 2013. Credit: LUMCON (Rabalais)

Farms trump industry in worries about European water pollution

EurActiv: When blood-red sludge broke through containment walls in the Hungarian town of Ajka in October 2010, the immediate concern was the safety of hundreds of nearby residents. In the end 10 people died from exposure and the toxic muck spilled into waterways, including the Danube, prompting alarms downstream. Spills on the magnitude of the one at the Ajka alumina plant are relatively rare and industrial pollution in many European rivers has declined since the 1960s. Tougher treatment laws, international cooperation and EU policies like the 2000 Water Framework Directive and 2006 Groundwater Directive are credited with the improvements.

While factories were once the big concern, more attention is focusing on pollution from farming, which accounts for more than half of land use in the EU and is overall the biggest consumer of water. Dietrich Borchardt is among those worried about agriculture’s effect on waterways.

“Acute industrial pollution is a rare case in Germany and even throughout Europe,” said Borchardt, who heads the Department of Aquatic Ecosystem Analysis at the Helmholtz Centre for Environmental Research in Germany. He attributes threats to “the excess rate of fertilisers”. “What we call good agricultural practice today,” Borchardt said in a telephone interview, “from a water perspective is not a good practice.”

Fertilisers typically contain nitrogen, phosphorous, potassium and sulphur, nutrients that help ensure healthy crops and boost yields. Commercial fertilisers use a form of nitrogen – nitrates - while organic fertilisers such as manure also contain high levels of the compound. Nitrates quickly leach into the soil and wash into streams, lakes and aquifers....

The red sludge from the alumina plant spill in Ajka, Hungary, photo by the Hungarian government

Dutch government introduces nitrogen-reduction bill for nature areas

Seed Daily via UPI: The Dutch government this week is pushing Parliament to pass a law that would reduce nitrogen leaching from farms and industrial sites into dozens of designated nature zones.

Dutch Economic Affairs Secretary Sharon Dijksma announced Monday that after years of debate on the issue of reducing nitrogen from farm waste runoff into the European Union-designated "Natura 2000" network of nature protection areas, a bill to do so has been submitted to lawmakers.

In a statement, Dijksma touted the government's Programmatic Approach to Nitrogen bill, which was first proposed in 2009 and has gone through several failed attempts and a prolonged period of negotiations with stakeholders such as farmers' organizations, provincial governments, local water boards, and industrial and transportation groups.

"In the Netherlands, more than 130 Natura 2000 sites have high loads of nitrogen," she said. "This is due to economic activities such as agriculture, transport and industry. This bill, the Programmatic approach to Nitrogen, brings clarity in the rules so that nature and the economy can be balanced for their mutual benefit."...

Sunset in a Dutch field, shot by FotoDutch, Wikimedia Commons, under the Creative Commons CC0 1.0 Universal Public Domain Dedication