Ecology, Climate Change and Related News

Conservation Science for a Healthy Planet

Tag Archive: soil

  1. Grazing Management to Improve Soil Health- rotational grazing can improve soil health over continuous grazing strategies

    Leave a Comment
    • Proper livestock grazing – which maintains and improves soil health – results in a series of interconnected positive outcomes including:
      • Soil densities and structure that allow root and water penetration of the entire soil profile.
      • Vigorous forage plants with capacity to develop and maintain extensive rooting systems.
      • A community of palatable forage plants with high rooting mass and depth.
      • Stable, resilient increases in primary productivity both above- and below- ground.

    Ken Tate April 9 2018  Read full UC Rangelands article here

    Grazing lands occupy nearly half the Earth’s land area, provide livelihoods for millions, and mitigate climate change via massive stores of carbon. Maintaining and restoring soil health is essential to ensuring these benefits in our ever changing environment.

    Thus, there is substantial global interest in managing livestock grazing to improve soil health. Grazing is promoted by some as a panacea for sequestering carbon and mitigating climate change. In other cases, grazing is depicted as an ultimate driver of soil degradation….

    …Our findings (Byrnes et al. 2018) suggest that rotational grazing can improve soil health over continuous grazing strategies. Decisions about grazing strategy and intensity significantly influence soil health outcomes, and site-specific conditions play important roles in shaping these out­comes.

    Byrnes, R.C., D.J. Eastburn, K.W. Tate, and L.M. Roche*. 2018. A global meta-analysis of grazing impacts on soil health indicators. J. Environmental Quality. doi:10.2134/jeq2017.08.0313.

    See previous post here.

  2. Can Responsible Grazing Make Beef Climate-Neutral?

    Leave a Comment
    • New research found that the greenhouse gases sequestered in one grass-fed system balanced out those emitted by the cows, but some meatless advocates are skeptical.
     

    There’s no denying Americans eat a lot of meat. In fact, the average U.S. citizen eats about 55 pounds of beef a year, including an estimated three hamburgers a week, and the United States Department of Agriculture (USDA) expects that amount to increase by about 3 percent by 2025. This heavy reliance on animal protein carries a big environmental footprint—livestock production contributes about 14.5 percent of global greenhouse gas (GHG) emissions, with beef constituting 41 percent of that figure, thanks to the methane cattle produce in the digestion process and the fact that overgrazing can release carbon stored in soils.

    ….A new five-year study that will be published in the May 2018 issue of the journal Agricultural Systems suggests that they can. Conducted by a team of researchers from Michigan State University (MSU) and the Union of Concerned Scientists (UCS), the study suggests that if cattle are managed in a certain way during the finishing phase, grassfed beef can be carbon-negative in the short term and carbon-neutral in the long term….

    ….“it is possible that long-term [adaptive multi-paddock grazing] AMP grazing finishing in the Upper Midwest could contribute considerably more to climate change mitigation and adaptation than previously thought.”

    Rather than using the common method of continuous grazing, in which cattle remain on the same pasture for an entire grazing season, the researchers used the more labor-intensive method of AMP, which entails moving the cattle at intervals ranging from days to months, depending on the type of forage, weather, time of year, and other considerations. A herd of adult cattle on MSU grazing land served as their test population.

    Though the study’s finding that strategic grazing can make a dent in the overall environmental impact of cattle runs counter to the widespread opinion among other researchers and climate activists, it is welcome news for advocates of regenerative agriculture.

    …. Tara Garnett, a food systems analyst and the founder of the Food Climate Research Network (FCRN) at the University of Oxford in England, calls the MSU work “a really useful study,” but also observes that it is “unclear how far this approach will lead to the same results elsewhere.” The study authors, too, are careful to stress that their results apply to Upper Midwestern conditions, and using a similar method in other ecosystem types will require further tailored study. They also acknowledge that while degraded land properly managed can take up large amounts of carbon, the soil will eventually reach equilibrium (meaning it will reach its carbon limit), and estimates of how long that takes vary widely.

    In addition, soil types and the many other aspects of climate and ecosystems in different regions require detailed understanding and granular management of grazing—something many beef producers may be unwilling to undertake. And grazing requires twice as much land as feedlots….

    …. One very promising practice, she said, is for ranchers to enlist farmers in the beef finishing phase. One farmer was initially very skeptical, but after he had grown a series of cover crops to rest his wheat fields and used cattle to “harvest” them, leaving the residue on the fields, he discovered that the soil was improving rapidly, Carman said. Reduced fertilizer and pesticide inputs, together with the income from the pasturage fees, makes the next wheat crop less expensive to grow.

    …. said Rowntree, “I hope our paper can give our industry, combined with policymakers, a lens that can potentially help. We’re not trying to pit one group against another.”

    Carman also acknowledges the complexity at hand, but feels the benefits to the soil she has seen are important to take into account. “Livestock are partly to blame for a lot of ecological problems we’ve got,” she said. “But we couldn’t repair these problems without livestock.”

    Paige L. Stanley, Jason E.Rowntree, David K.Beede, Marcia S.DeLonge, Michael W.Hamm. Impacts of soil carbon sequestration on life cycle greenhouse gas emissions in Midwestern USA beef finishing systems.  Agricultural Systems Volume 162, May 2018, Pages 249-258 https://doi.org/10.1016/j.agsy.2018.02.003

    See previous post on this here. 

    And related NPR story:

    A Grass-Roots Movement For Healthy Soil Spreads Among Farmers

    April 9 2018 America’s farmers are digging soil like never before. A movement for “regenerative agriculture” is dedicated to building healthier soil and could even lead to a new eco-label on food.

  3. Vegetation controls the future of the water cycle

    Leave a Comment
    • This study highlights the key role of vegetation in controlling future terrestrial hydrologic response.
    • Carbon and water cycles are intimately coupled over land and must be studied as an interconnected system.
    • Hydrologists should collaborate with ecologists and climate scientists to better predict future water resources.
    • “Plants are at the center of the water, energy, and carbon cycles. As they take up carbon from the atmosphere to thrive, they release water that they take from the soils. Doing that, they also cool off the surface, controlling the temperature that we all feel. Now we know that mainly plants- not simply precipitation or temperature-will tell us whether we will live a drier or wetter world.”

    April 2, 2018 Columbia University School of Engineering and Applied Science Read full Science Daily Article here

    Researchers have found that vegetation plays a dominant role in Earth’s water cycle, that plants will regulate and dominate the increasing stress placed on continental water resources in the future…

    …”The biosphere physiological effects and related biosphere-atmosphere interactions are key to predicting future continental water stress as represented by evapotranspiration, long-term runoff, soil moisture, or leaf area index,” Gentine says. “In turn, vegetation water stress largely regulates land carbon uptake, further emphasizing how tightly the future carbon and water cycles are coupled so that they cannot be evaluated in isolation.”

    ….Gentine and Lemordant plan to further untangle the various physiological effects. “The vegetation response is itself indeed complex,” Gentine says, “and we want to decompose the impact of biomass growth vs. stomatal response. There are also implications for extreme heatwave events we are currently working on.”

    “This work highlights an important need to further study how plants will respond to rising atmospheric carbon dioxide,” says James Randerson, professor of earth system science, University of California, Irvine, who was not involved with the study. “Plants can have a big effect on the climate of land, and we need to better understand the ways that they will respond to carbon dioxide, warming, and other forms of global change.”

    Léo Lemordant et al. Critical impact of vegetation physiology on the continental hydrologic cycle in response to increasing CO2. PNAS, 2018 DOI: 10.1073/pnas.1720712115

  4. Digging deep: Harnessing the power of soil microbes for more sustainable farming

    Leave a Comment
    • Farm of the future’ project marries microbiology and machine learning
    March 14, 2018 DOE/Lawrence Berkeley National Laboratory Read full ScienceDaily article here
    How will the farms of the future feed a projected 9.8 billion people by 2050? A ‘smart farm’ project marries microbiology and machine learning in an effort to reduce the need for chemical fertilizers and enhance soil carbon uptake, thus improving the long-term viability of the land while increasing crop yields….
    …this project brings together molecular biology, biogeochemistry, environmental sensing technologies, and machine learning, will revolutionize agriculture and create sustainable farming practices that benefit both the environment and farms. If successful, they envision being able to reduce the need for chemical fertilizers and enhance soil carbon uptake, thus improving the long-term viability of the land, while at the same time increasing crop yields.A central piece of the research is understanding the role of microbes in the health of the soil….”By understanding how microbes work and modifying the environments where they function, we can eventually engineer microbial communities to enhance soil productivity. What’s more, Berkeley Lab’s research is showing that healthy soils are more resilient to system shocks such as climate change, drought, and insects.”

    …The world’s population is forecast by the United Nations to grow to 9.8 billion by 2050; feeding that many people will require raising food production by more than 70 percent. Yet industrialized farming practices have depleted a majority of the country’s agricultural land of active carbon and a balanced microbial ecosystem. This is reflected in measurements of organic matter that average only 1 to 2 percent in most farmland, compared to historic levels of around 10 percent…

    …”There are millions of species of microbes per cubic centimeter of soil,” Brown said. “As you approach the plant root and its interior tissues, you go from millions to dozens. So plants do an exceptional job of farming their microbiomes. They release materials, including antimicrobial compounds, to selectively kill undesirable microbes, and they release food to incentivize beneficial microbes. It’s a highly symbiotic and enormously complex interaction, and we understand almost nothing about it.”

    …Hyperspectral sensors on the drones will be able to detect light reflectance from the plants and see hundreds of channels of spectra, from the visible to near infrared. “The human eye has only three channels — red, green, and blue,” said Wainwright. “You can see if a leaf looks yellow or green. But with hundreds of channels you can measure carbon and nitrogen content, and you can tell a lot about plant health, plant disease, or leaf chemistry, all of which affect crop yield.”

    In addition, surface geophysical techniques are used to map soil electrical properties in 3-D, which greatly controls soil microbial activities.

    Machine learning is the tool that will tie all the data together…

    …Currently farmers have no such information, even though services and products have sprung up providing various “big data” solutions. “All the private companies have a big incentive to lock their own data sets, so they can’t be used in conjunction with other data sets,” Wainwright said. “That’s where the public sector, like Berkeley Lab, can step in. We’re not incentivized by profit.”…

  5. 12 Emerging Global Trends That Bring Hope for 2018

    Leave a Comment

    Feb 2018 Read full The Nature Conservancy article here

    …New environmental leaders are stepping up across different sectors and geographies; new sources of financing are starting to close the gap in conservation funding; collective governance is emerging to better manage precious resources. Without minimizing the task ahead, we want to point to some trends that are unlocking investment for nature and offering hope for a sustainable future. Download our one-pager here.

    1. High Time for the High Seas

    Could the biggest thing to happen for the environment in decades be in the middle of the ocean?

    2. A New Prescription for Public Health

    A tree a day keeps the doctor away?

    3. Following the Money to Global Impact

    What happens when investing for good meets financial reward?

    4. New Faces Tackling Climate Change

    Who will step up on this generation’s main stage?

    5. Natural Climate Solutions: the Year’s Top Carbon Technology

    Solving for future carbon emissions is one thing; removing carbon dioxide already in the atmosphere is another. Can we do both today?

    6. Soil—Believe it or Not—is a Hot Topic

    Here’s the dirt: this year, soil is on trend.

    7. Engineering Our Way Out of Crisis—with Nature’s Help

    The trillion-pound (£) elephant in the room? Infrastructure.

    8. Big Data and the Dawn of a Conservation Revolution

    A welcome disruption? The tech industry is setting its sights on a new sector: conservation.

    9. More Companies Are Getting Serious About Global Green Goals

    What to do with SDGs and two degrees?

    10. Clean Energy Is Powering The Future—Now Where to Put It?

    Our clean energy future is arriving faster than we thought.

    11. To Redefine Green Design, Cities Are Thinking Bigger—AND Smaller

    Cities still strive for LEED buildings and light rail—but also a better walk down the block.

    12. Oh, and One More Thing—More

    More investment, more research, more accountability, more heroes.

  6. Adaptive multi-paddock grazing can sequester large amounts of soil C

    Leave a Comment
    • Emissions from the grazing system were offset completely by soil C sequestration.
    • Soil C sequestration from well-managed grazing may help to mitigate climate change.
    • This research suggests that AMP grazing can contribute to climate change mitigation through SOC sequestration and challenges existing conclusions that only feedlot-intensification reduces the overall beef GHG footprint through greater productivity.

    Environmentally friendly cattle production (really)

    March 19, 2018 Michigan State University read full ScienceDaily article here
    When cattle congregate, they’re often cast as the poster animals for overgrazing, water pollution and an unsustainable industry. While some of the criticism is warranted, cattle production — even allowing herds to roam through grasslands and orchards — can be beneficial to the environment as well as sustainable….

    Paige L. Stanley, Jason E. Rowntree, David K. Beede, Marcia S. DeLonge, Michael W. Hamm. Impacts of soil carbon sequestration on life cycle greenhouse gas emissions in Midwestern USA beef finishing systems. Agricultural Systems, 2018; 162: 249 DOI: 10.1016/j.agsy.2018.02.003

    Abstract

    Beef cattle have been identified as the largest livestock-sector contributor to greenhouse gas (GHG) emissions. Using life cycle analysis (LCA), several studies have concluded that grass-finished beef systems have greater GHG intensities than feedlot-finished (FL) beef systems. These studies evaluated only one grazing management system – continuous grazing – and assumed steady-state soil carbon (C), to model the grass-finishing environmental impact. However, by managing for more optimal forage growth and recovery, adaptive multi-paddock (AMP) grazing can improve animal and forage productivity, potentially sequestering more soil organic carbon (SOC) than continuous grazing. To examine impacts of AMP grazing and related SOC sequestration on net GHG emissions, a comparative LCA was performed of two different beef finishing systems in the Upper Midwest, USA: AMP grazing and FL. We used on-farm data collected from the Michigan State University Lake City AgBioResearch Center for AMP grazing. Impact scope included GHG emissions from enteric methane, feed production and mineral supplement manufacture, manure, and on-farm energy use and transportation, as well as the potential C sink arising from SOC sequestration. Across-farm SOC data showed a 4-year C sequestration rate of 3.59 Mg C ha−1 yr−1 in AMP grazed pastures.

    After including SOC in the GHG footprint estimates, finishing emissions from the AMP system were reduced from 9.62 to −6.65 kg CO2-e kg carcass weight (CW)−1, whereas FL emissions increased slightly from 6.09 to 6.12 kg CO2-e kg CW−1 due to soil erosion. This indicates that AMP grazing has the potential to offset GHG emissions through soil C sequestration, and therefore the finishing phase could be a net C sink. However, FL production required only half as much land as AMP grazing. While the SOC sequestration rates measured here were relatively high, lower rates would still reduce the AMP emissions relative to the FL emissions. This research suggests that AMP grazing can contribute to climate change mitigation through SOC sequestration and challenges existing conclusions that only feedlot-intensification reduces the overall beef GHG footprint through greater productivity.

     

  7. Keeping the world below 2°C of warming requires negative emissions tech we don’t have (European Academies report)

    Leave a Comment
    • European national science academies report warns tepid emission cuts not enough.
    • A new European Academies Science Advisory Council (EASAC) report looks at a number of options, including reforestation, soil management, plankton fertilization, industrial CO2 capture plants, biofuels with emissions injected underground for storage, and even the boosting of bedrock weathering reactions.
    • The report’s conclusions: we have to develop carbon dioxide removal schemes more aggressively, but we also have to cut our emissions enough that we don’t rely on those schemes to save us.
  8. Microplastics — an emerging threat to terrestrial ecosystems.

    Leave a Comment
    These are polyacrylic fibers in soil. Credit: Anderson Abel de Souza Machado
    • Over 400 million tons of plastic are produced globally each year. It is estimated that one third of all plastic waste ends up in soils or freshwaters.
    • Terrestrial microplastic pollution is much higher than marine microplastic pollution — an estimate of four to 23 times more, depending on the environment.
    • When plastic particles break down, they gain new physical and chemical properties, increasing the risk that they will have a toxic effect on organisms
    • 80 to 90 per cent of the particles contained in sewage, such as from garment fibres, persist in the sludge. Sewage sludge is then often applied to fields as fertilizer, meaning that several thousand tons of microplastics end up in our soils each year.
    • The intake and uptake of small microplastics could turn out to be the new long-term stress factor for the environment.

    February 5, 2018 Forschungsverbund Berlin read full ScienceDaily article here

    Tiny plastic particles also present a threat to creatures on land and may have damaging effects similar or even more problematic than in our oceans. Researchers warn: the impact of microplastics in soils, sediments and the freshwaters could have a long-term negative effect on terrestrial ecosystems throughout the world.

    Over 400 million tons of plastic are produced globally each year. It is estimated that one third of all plastic waste ends up in soils or freshwaters. Most of this plastic disintegrates into particles smaller than five millimetres, referred to as microplastics, and breaks down further into nanoparticles, which are less than 0.1 micrometre in size.

    In fact, terrestrial microplastic pollution is much higher than marine microplastic pollution — an estimate of four to 23 times more, depending on the environment. Sewage, for example, is an important factor in the distribution of microplastics. In fact, 80 to 90 per cent of the particles contained in sewage, such as from garment fibres, persist in the sludge. Sewage sludge is then often applied to fields as fertilizer, meaning that several thousand tons of microplastics end up in our soils each year.

    Some microplastics exhibit properties that might have direct damaging effects on ecosystems. For instance, the surfaces of tiny fragments of plastic may carry disease-causing organisms and act as a vector that transmits diseases in the environment. Microplastics can also interact with soil fauna, affecting their health and soil functions. Earthworms, for example, make their burrows differently when microplastics are present in the soil, affecting the earthworm’s fitness and the soil condition.Generally speaking, when plastic particles break down, they gain new physical and chemical properties, increasing the risk that they will have a toxic effect on organisms. And the more likely it is that toxic effects will occur, the larger the number of potentially affected species and ecological functions……..Humans also ingest microplastics via food: they have already been detected not only in fish and seafood, but also in salt, sugar and beer. It could be that the accumulation of plastics in terrestrial organisms is already common everywhere, the researchers speculate, even among those that do not “ingest” their food. For example, tiny fragments of plastic can be accumulated in yeasts and filamentous fungi.The intake and uptake of small microplastics could turn out to be the new long-term stress factor for the environment.

     

    Anderson Abel de Souza Machado, Werner Kloas, Christiane Zarfl, Stefan Hempel, Matthias C. Rillig. Microplastics as an emerging threat to terrestrial ecosystems. Global Change Biology, 2018; DOI: 10.1111/gcb.14020
    These are polyacrylic fibers in soil. Credit: Anderson Abel de Souza Machado
    And another recent study:
    Melanie Bläsing, Wulf Amelung. Plastics in soil: Analytical methods and possible sources. Science of the Total Environment. 2017
    H I G H L I G H T S
    • Analytical methods and possible input pathways of plastic in soil were discussed.
    • Organic matter challenges plastic quantification in soil.
    • Soil amendments and irrigation are likely major plastic sources in agricultural soils.
    • Flooding, atmospheric input and littering can potentially pollute even remote soil.
    • Leaching of small plastics from soil into groundwater cannot be excluded.

  9. Fertilized soil in the Central Valley produces 40% of CA’s nitrogen oxides emissions

    Leave a Comment

    January 31, 2018 UCDavis read full ScienceDaily article here

    A previously unrecognized source of nitrogen oxide is contributing up to about 40 percent of the NOx emissions in California, according to a new study. The study traces the emissions to fertilized soils in the Central Valley region….

    …Fossil fuels have long been recognized as a major contributor to NOx pollution. Technologies like the catalytic converter have helped greatly reduce NOx emitted from vehicles in urban areas. But some of the state’s worst air quality problems are now in rural areas, particularly the Central Valley region, which is home to some of the poorest communities in California.

    The Central Valley is also one of the world’s most highly productive agricultural areas. Roughly half of the fruits and nuts produced in the United States are grown there. This includes nearly all the nation’s almonds, walnuts, raisins, avocados, and tomatoes….

    ….“Only about half of the nitrogen fertilizer applied to crops are used by the plant. But slow-release fertilizers that deliver nutrients in a way that more closely mimics nature have been shown to greatly improve nitrogen use efficiency of crops, reducing emissions of nitrogen in the environment. Healthy soils programs that restore carbon in the soil can also help fight climate change and are likely to increase nutrient retention and cycling to crops….

    ….The state also began a program this year in which growers work in coalitions to gather information on efficient uses of nitrogen so they can evaluate how and where the state needs to manage nitrogen in agricultural areas. This work aims to reduce nitrate in the groundwater but it may have a double benefit in reducing NOx emissions.”…

    Maya Almaraz, Edith Bai, Chao Wang, Justin Trousdell, Stephen Conley, Ian Faloona, Benjamin Z. Houlton. Agriculture is a major source of NO x pollution in California. Science Advances, 2018; 4 (1): eaao3477 DOI: 10.1126/sciadv.aao3477

  10. Cattle Ranchers Join Conservationists To Save Endangered Species And Rangelands

    Leave a Comment
    • To preserve these landscapes for future generations, ranchers need payment and recognition for their ecosystem services “in order to preserve these working landscapes for future generations,” Huntsinger writes.
    • She and other researchers have found that many ranches are better than nature preserves at protecting native plants and animals, partly because ranches are watered and cow manure enriches the soil. California’s Mediterranean-like rangeland, researchers say, provides social and ecological services of natural beauty, biodiversity, environmental stewardship and open space protection and recreation.

    …The partnership between ranchers and conservationists in Idaho is part of a national trend — and one that may help keep ranchers themselves off the endangered species list.

    Cattle ranching is a historic way of life in the West, but it’s under siege, threatened by development, drought, wildfires, a shrinking number of cattle buyers and razor-thin profit margins. But land trusts, conservation easements and payments for ecosystem services (such as wetlands) offer hope that rangelands and their wildlife can survive and even flourish.

    How does this work? Some conservation agencies, like Idaho’s, offer cost-sharing with ranchers, while other Payments for Ecosystem Services (PES) cover all the costs or pay ranchers directly for wildlife programs. Ranchers who set land aside in permanent conservation easements receive estate benefits and federal tax savings for up to 15 years. And some land trusts, such as the Ranchland Trust of Kansas, allow ranchers to specify that their grassland legacy continue to be ranched.

    More than a decade ago, a group of ranchers alarmed about vanishing rangelands formed the California Rangeland Conservation Coalition, which united two groups that traditionally viewed each other as enemies. Today nearly a third of the state’s ranchers are working to restore wetlands and meadows and plant native plants….

    ….California has a strong incentive to preserve its 18 million acres of ranchland: Cattle and calves are the state’s fourth-leading agricultural commodities (milk and cream are No. 1), according to state agricultural data. But in a Duke University survey of the state’s ranchers, more than half said they were “more uncertain than ever” that they would be able to continue ranching. California is losing an estimated 20,000 acres of rangeland each year, according to the Nature Conservancy, and on any given day ads for the sale of cattle ranches dot the Internet. The median age of California ranchers is 58 to 62, and more are aging out of the business with no children interested in taking over the ranch.

    But this trend can be reversed, according to Lynn Huntsinger a professor of environmental science and rangeland ecology at UC Berkeley. To preserve these landscapes for future generations, ranchers need payment and recognition for their ecosystem services “in order to preserve these working landscapes for future generations,” Huntsinger writes.

    She and other researchers have found that many ranches are better than nature preserves at protecting native plants and animals, partly because ranches are watered and cow manure enriches the soil. California’s Mediterranean-like rangeland, researchers say, provides social and ecological services of natural beauty, biodiversity, environmental stewardship and open space protection and recreation….