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Conservation Science for a Healthy Planet

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

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    • 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….

  2. The Ecology of Soil Carbon: Pools, Vulnerabilities, and Biotic and Abiotic Controls- and Questions for Future Research

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    • Soils hold the largest biogeochemically active terrestrial carbon pool on Earth and are critical for stabilizing atmospheric CO2 concentrations. Nonetheless, global pressures on soils continue from changes in land management, including the need for increasing bioenergy and food production

    Jackson, Robert, et al. The Ecology of Soil Carbon: Pools, Vulnerabilities, and Biotic and Abiotic Controls. The Annual Review of Ecology, Evolution, and Systematics.  September 2017. 48:419–45 https://doi.org/10.1146/annurev-ecolsys 112414-054234

    Soil organic matter (SOM) anchors global terrestrial productivity and food and fiber supply. SOM retains water and soil nutrients and stores more global carbon than do plants and the atmosphere combined. SOM is also decomposed by microbes, returning CO2, a greenhouse gas, to the atmosphere. Unfortunately, soil carbon stocks have been widely lost or degraded through land use changes and unsustainable forest and agricultural practices.

    To understand its structure and function and to maintain and restore SOM, we need a better appreciation of soil organic carbon (SOC) saturation capacity and the retention of above- and belowground inputs in SOM. Our analysis suggests root inputs are approximately five times more likely than an equivalent mass of aboveground litter to be stabilized as SOM. Microbes, particularly fungi and bacteria, and soil faunal food webs strongly influence SOM decomposition at shallower depths, whereas mineral associations drive stabilization at depths greater than ∼30 cm. Global uncertainties in the amounts and locations of SOM include the extent of wetland, peatland, and permafrost systems and factors that constrain soil depths, such as shallow bedrock. In consideration of these uncertainties, we estimate global SOC stocks at depths of 2 and 3 m to be between 2,270 and 2,770 Pg, respectively, but could be as much as 700 Pg smaller. Sedimentary deposits deeper than 3 m likely contain > 500 Pg of additional SOC. Soils hold the largest biogeochemically active terrestrial carbon pool on Earth and are critical for stabilizing atmospheric CO2 concentrations. Nonetheless, global pressures on soils continue from changes in land management, including the need for increasing bioenergy and food production

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    Excerpts on future directions:

    2.1. Emerging Research Questions for Plant Production, Allocation, and SOM:
    1. What is the relative contribution of roots compared with that of litter inputs to the accumulation of SOM under different vegetation types, soil conditions, land uses, and climates?
    2. Is the higher CUE of root litter compared with that of aboveground litter explained by differences in chemical composition or root-soil interactions?
    3. What is the fate of nutrients such as nitrogen and phosphorus from aboveground and belowground organic matter respired during decomposition, and what is their role in SOM formation?
    4. In consideration of trade-offs with production, how feasible is it to manage plant allocation patterns in managed landscapes to sequester SOM but maintain growth and yield?
    3.1. Emerging Research Questions for Belowground Food Webs and Soil Ecology
    Although it is well established that microbes and soil fauna exert strong controls on the rates and pathways of plant litter decay, their role in soil carbon stabilization is less clear. Mycorrhizae have a strong role in carbon stabilization in many ecosystems, but the relative role of fungi in soil carbon stabilization, compared with that of bacteria, is not well characterized. Several questions deserve particular attention:
    1. How critical is understanding microbial physiology to predicting future changes in soil carbon stocks with climate change?
    2. Will microbial CUE be altered by global warming, will thermal adaptation occur, or will broad changes in the microbial community lead to unexpected changes in soil carbon stabilization patterns?
    3. How will changes in future vegetation patterns affect detrital inputs to soil and the stabilization of these inputs?
    4. Do soil fauna need to be added to models of SOM that include microbes?

    4.1. Emerging Research Questions for Biotic–Abiotic Interactions and SOM

    1. How will interactions between biotic processes (e.g., NPP, detrital inputs, and microbial activity) and carbon retention on mineral surfaces be altered by climate change?
    2. Do soil minerals and their interactions with biotic processes need to be included in future SOM models?
    3. How can abiotic and biotic factors be incorporated into land surface and Earth system models to reduce future uncertainty?
    5.3. Emerging Research Questions for Global SOM Stocks, Distributions, and Controls:
    Answers to the following important research questions could help close the data gap:
    1. How can we better constrain the distributions of peatland and permafrost systems, the amount of SOC and SON they contain, and their vulnerability to a warming climate?
    2. How can computational approaches enhance our understanding of depth distributions for SOM and their biotic and abiotic controls?
    3. How can we best improve and verify estimates of bedrock depth and its influence on the global content of SOC and SON?
    Soil carbon is vulnerable to oxidation and release to the atmosphere through a variety of human activities (Figure 1), including land use disturbance and the effects of climate change. The greatest human-induced loss of SOC has come from the conversion of native forests and grasslands to annual crops (Paustian et al. 1997, Lal 2004). Understanding the role of agricultural management on SOC stocks is therefore critical both for predicting future carbon fluxes and for devising best-management strategies to mitigate and reverse soil loss…. Mitigating and even reversing these land use effects, however, are both possible and desirable (Minansy et al. 2017)….. The initial status of the land is critical to the interpretation of afforestation studies. A degraded system often gains SOM with afforestation or other management; a healthy, native ecosystem may sometimes lose it….
    ….The adoption of soil conservation practices such as reduced tillage, improved residue management, reduced bare fallow, and conservation reserve plantings has stabilized, and partially reversed, SOC loss in North American agricultural soils (Paustian et al. 2016)….Improved grazing management, fertilization, sowing legumes, and improved grass species are additional ways to increase soil carbon by as much as 1 Mg C ha−1year−1 (Conant et al. 2017)…
    ….Ecosystem and Earth system models can improve their representations of SOM by adding modifiers and microbial attributes that influence SOM formation and stabilization across scales….
    ….Over the next century, most projected land use change is expected to arise from repurposing existing agricultural land rather than clearing native forests (Watson et al. 2014). Emerging land use activities that combine carbon sequestration with crop production offer great promise to increase global SOM while sustainably meeting food and fiber production for an increasing human population (Francis et al. 2016).

    ….anthropogenic greenhouse gas emissions have altered the planet’s climate, including

    temperatures, precipitation, and vapor pressure deficit, and will continue to do so. Additional changes are apparent in the patterns and extremes of weather and in the frequency, intensity, and severity of disturbances. All the factors, knowledge, and skill illustrated through the examples in this review will be needed to project the effects of climate change on SOM. Global pressures on soils are coming from continuing changes in land management, such as the need for increasing bioenergy and food production. For these reasons and more, furthering progress in experiments, synthesis, and modeling of SOM will remain a research priority for decades..

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    Other links to aggregated content on soil science, carbon sequestration and range science:

  3. Soil Carbon: 3 recent papers on soil carbon pathways

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    • Plant diversity enhances soil microbial biomass, particularly soil fungi, by increasing root-derived organic inputs.
    • Build on emerging evidence that points to significant consumption of labile (easily altered) carbon (C) by fungi, and to the ability of ectomycorrhizal fungi to decompose organic matter, researchers show that labile C constitutes a major and presently underrated source of C for the soil food web.
    • The magnitude of the organic C reservoir in soils depends upon microbial growth and activity but it remains largely unknown how these microorganism-mediated processes lead to soil C stabilization. Authors define two pathways—ex vivo modification and in vivo turnover—which jointly explain soil C dynamics driven by microbial catabolism and/or anabolism through the soil MCP (microbial carbon pump) — a conceptual guideline for improving understandings of how soil C dynamics contribute to the responses of the terrestrial C cycle under global change.

    Nico Eisenhauer, Arnaud Lanoue, Tanja Strecker, Stefan Scheu, Katja Steinauer, Madhav P. Thakur & Liesje Mommer Root biomass and exudates link plant diversity with soil bacterial and fungal biomass. Scientific Reports 7, Article number: 44641 (2017) doi:10.1038/srep44641 Published online: 04 April 2017

    Abstract: Plant diversity has been shown to determine the composition and functioning of soil biota. Although root-derived organic inputs are discussed as the main drivers of soil communities, experimental evidence is scarce. While there is some evidence that higher root biomass at high plant diversity increases substrate availability for soil biota, several studies have speculated that the quantity and diversity of root inputs into the soil, i.e. though root exudates, drive plant diversity effects on soil biota. Here we used a microcosm experiment to study the role of plant species richness on the biomass of soil bacteria and fungi as well as fungal-to-bacterial ratio via root biomass and root exudates. Plant diversity significantly increased shoot biomass, root biomass, the amount of root exudates, bacterial biomass, and fungal biomass. Fungal biomass increased most with increasing plant diversity resulting in a significant shift in the fungal-to-bacterial biomass ratio at high plant diversity. Fungal biomass increased significantly with plant diversity-induced increases in root biomass and the amount of root exudates. These results suggest that plant diversity enhances soil microbial biomass, particularly soil fungi, by increasing root-derived organic inputs.

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    Franciska T.de Vriesa and Tancredi Carusob. Eating from the same plate? Revisiting the role of labile carbon inputs in the soil food web. Soil Biology and Biochemistry. Volume 102, November 2016, Pages 4-9  https://doi.org/10.1016/j.soilbio.2016.06.023

    Highlights

    • The fundamental assumptions in the classical soil food web are being challenged.
    • We argue that labile (easily changed) C forms a large and dynamic C input to the soil food.
    • We show that fungi and bacteria can coexist with significant fungal labile C use.
    • We propose a new labile C driven conceptual model based on these findings.
    • These concepts will increase our understanding of soil food web dynamics.

    Abstract

    An increasing number of empirical studies are challenging the central fundamentals on which the classical soil food web model is built. This model assumes that bacteria consume labile substrates twice as fast as fungi, and that mycorrhizal fungi do not decompose organic matter. Here, we build on emerging evidence that points to significant consumption of labile C by fungi, and to the ability of ectomycorrhizal fungi to decompose organic matter, to show that labile C constitutes a major and presently underrated source of C for the soil food web. We use a simple model describing the dynamics of a recalcitrant and a labile C pool and their consumption by fungi and bacteria to show that fungal and bacterial populations can coexist in a stable state with large inputs into the labile C pool and a high fungal use of labile C. We propose a new conceptual model for the bottom trophic level of the soil food web, with organic C consisting of a continuous pool rather than two or three distinct pools, and saprotrophic fungi using substantial amounts of labile C. Incorporation of these concepts will increase our understanding of soil food web dynamics and functioning under changing conditions.

    carbon pathway

    Primary production inputs to soils occur through two pathways—in vivo turnover and ex vivo modification that jointly explain soil C dynamics driven by microbial catabolism and/or anabolism before entering the stable soil C pool. Even though the relative importance of in vivo turnover (red lines) and ex vivo modification (green lines) vary with different environmental scenarios, we argue that the majority of C that is persistent in soils occurs through coupling of the soil microbial carbon pump (MCP; associated with the in vivo turnover pathway) to stabilization via the entombing effect. The soil MCP is a conceptual object to demonstrate the fact that microbial necromass and metabolites can be the precursors for persistent soil C, which particularly highlights the importance of microbial anabolism in soil C storage. The yinyang symbol is used to create a sense of movement and illustrate that the movement is driven, but driven differently, by both bacteria and fungi with different trophic lifestyles.

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    Liang, C., Schimel, J. P. & Jastrow, J. D. The importance of anabolism in microbial control over soil carbon storageNature Microbiology 2, 17105 (2017).

    Studies of the decomposition, transformation and stabilization of soil organic matter (SOM) have dramatically increased in recent years owing to growing interest in studying the global carbon (C) cycle as it pertains to climate change. While it is readily accepted that the magnitude of the organic C reservoir in soils depends upon microbial involvement, as soil C dynamics are ultimately the consequence of microbial growth and activity, it remains largely unknown how these microorganism-mediated processes lead to soil C stabilization. Here, we define two pathways—ex vivo modification and in vivo turnover—which jointly explain soil C dynamics driven by microbial catabolism and/or anabolism. Accordingly, we use the conceptual framework of the soil ‘microbial carbon pump’ (MCP) to demonstrate how microorganisms are an active player in soil C storage. The MCP couples microbial production of a set of organic compounds to their further stabilization, which we define as the entombing effect. This integration captures the cumulative long-term legacy of microbial assimilation on SOM formation, with mechanisms (whether via physical protection or a lack of activation energy due to chemical composition) that ultimately enable the entombment of microbial-derived C in soils. We propose a need for increased efforts and seek to inspire new studies that utilize the soil MCP as a conceptual guideline for improving mechanistic understandings of the contributions of soil C dynamics to the responses of the terrestrial C cycle under global change.

  4. Nudging Natural Magic– Oro Loma Horizontal Levee Sea Level Rise Adaptation Pilot

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    • Preliminary results of the Oro Loma horizontal levee experiment on the San Lorenzo shore (SF Bay) include off the charts levels of removal of nitrogen and pharmaceuticals from wastewater passed through the system and growth of willows, cattails, and wet meadows.
    • Modernizing the planning and regulatory context for resilience projects is an emerging regional priority.
    By Ariel Rubissow Okamoto December 2017 SF Estuary Partnership   read full Estuary article here

    “Miraculous” isn’t a term that comes easily to the lips of scientists and engineers. But the word, along with a quickly quelled gulp of incredulity, cropped up more than once in interviews concerning the preliminary results of the horizontal levee experiment on the San Lorenzo shore – including off the charts levels of removal of nitrogen and pharmaceuticals from wastewater passed through the system and growth of willows, cattails, and wet meadows

    This pilot sea level rise adaptation project, led by the Oro Loma Sanitary District, combines precision engineering, native plants, irrigation via treated household wastewater, and a hump of bay mud, sand, and gravel. The idea is to test which ingredients –liquid, solid, vegetable –in what doses and combinations make the levee bulk up and leaf out fastest, and best “polish” (clean) the wastewater….

    …But perhaps the most extraordinary early result is coming from an examination of the quality of the treated wastewater that passes through the levee and all its elaborate hardware, soil zones, and root systems. Researcher Angela Perantoni is one of a team intensely monitoring exactly what gets put into pipes at the top of the experimental levee and what comes out at the bottom, or what engineers call the “toe” of the slope. “A lot of constructed wetlands designed to polish wastewater are monocultures made up of pea-sized gravel and common reeds,” says Perantoni. “This project took the time to create a more diverse, native situation.”…


    Participants in the Resilient by Design challenge visit the horizontal levee in fall 2017, with the jungle of plant growth behind them and a wet-weather basin to be tested this winter out front. Photo Ariel Rubissow Okamoto

    ….Though these preliminary results are just beginning to be tested under colder, wetter, more wintry conditions, planners and engineers are already thinking about bigger, longer versions of the horizontal levee in Palo Alto, Richmond, Novato, and Hayward. Each of these new levees might, however, have a different emphasis than the one at Oro Loma in terms of habitat or flood control or water quality.

    ….“Based on the current regulations, they can’t treat us any differently than a developer who wants to construct a Walmart at the edge of the Bay,” says Warner.  The district had to spend a million before it even knew it could get a permit, he says, as well as construct new wetlands to replace old degraded ones and build an expensive berm around the entire project to preclude any leaks.

    Modernizing the planning and regulatory context for resilience projects is an emerging regional priority. Indeed creating new pathways for building multi-benefit natural infrastructure projects is an action item regional partners have already agreed was needed in the 2016 Estuary Blueprint.  Progress in this endeavor includes regulatory analysis and guidance under the Flood 2.0 project, and continued public-private collaboration around projects like Oro Loma….

  5. Healthy soils can play big role in avoiding climate catastrophe- NY Times Op-Ed

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    • Regenerative agriculture will be a key part of solving the climate crisis

    DEC. 2, 2017 Read NYTimes article here

    The last great hope of avoiding catastrophic climate change may lie in a substance so commonplace that we typically ignore it or else walk all over it: the soil beneath our feet.

    The earth possesses five major pools of carbon. Of those pools, the atmosphere is already overloaded with the stuff; the oceans are turning acidic as they become saturated with it; the forests are diminishing; and underground fossil fuel reserves are being emptied. That leaves soil as the most likely repository for immense quantities of carbon.

    Now scientists are documenting how sequestering carbon in soil can produce a double dividend: It reduces climate change by extracting carbon from the atmosphere, and it restores the health of degraded soil and increases agricultural yields. Many scientists and farmers believe the emerging understanding of soil’s role in climate stability and agricultural productivity will prompt a paradigm shift in agriculture, triggering the abandonment of conventional practices like tillage, crop residue removal, mono-cropping, excessive grazing and blanket use of chemical fertilizer and pesticide. Even cattle, usually considered climate change culprits because they belch at least 25 gallons of methane a day, are being studied as a potential part of the climate change solution because of their role in naturally fertilizing soil and cycling nutrients.

    The climate change crisis is so far advanced that even drastically cutting greenhouse gas emissions won’t prevent a convulsive future by itself — the amount of greenhouse gases already in the atmosphere ensures dire trouble ahead. The most plausible way out is to combine emission cuts with “negative-emission” or “drawdown” technologies, which pull greenhouse gases out of the atmosphere and into the other pools. Most of these proposed technologies are forms of geoengineering, dubious bets on huge climate manipulations with a high likelihood of disastrous unintended consequences.

    On the other hand, carbon sequestration in soil and vegetation is an effective way to pull carbon from the atmosphere that in some ways is the opposite of geoengineering. Instead of overcoming nature, it reinforces it, promoting the propagation of plant life to return carbon to the soil that was there in the first place — until destructive agricultural practices prompted its release into the atmosphere as carbon dioxide. That process started with the advent of agriculture about 10,000 years ago and accelerated over the last century as industrial farming and ranching rapidly expanded.

    Among the advocates of so-called regenerative agriculture is the climate scientist and activist James Hansen, lead author of a paper published in July that calls for the adoption of “steps to improve soil fertility and increase its carbon content” to ward off “deleterious climate impacts.

    Rattan Lal, the director of the Carbon Management and Sequestration Center at Ohio State, estimates that soil has the potential to sequester carbon at a rate of between 0.9 and 2.6 gigatons per year. That’s a small part of the 10 gigatons a year of current carbon emissions, but it’s still significant. Somewhat reassuringly, some scientists believe the estimate is low.

    ….The techniques that regenerative farmers use vary with soil, climate and crop. They start from the understanding that healthy soil teems with more than a billion microorganisms per teaspoon and the behavior of those organisms facilitates hardy plant life. To fertilize their fields, regenerative farmers use nutrient-rich manure or compost, avoiding as much as possible chemical fertilizers and pesticides, which can kill huge quantities of organic matter and reduce plants’ resilience. They don’t like to till the soil, since tillage increases carbon emissions into the atmosphere. Some farmers combine livestock, cover crops and row crops sequentially on the same field, or plant perennials, shrubs and even trees along with row crops. Leaving soil bare during off-seasons is taboo, since barren soil easily erodes, depleting more carbon from the soil; regenerative farmers instead plant cover crops to capture more carbon and nitrogen from the atmosphere….

    …California began an initiative in 2015 to incorporate soil health into the state’s farm and ranch operations. Some of the pioneering studies showing regenerative agriculture’s benefits have been carried out at the Marin Carbon Project, on a self-proclaimed carbon-farming ranch in the pastoral reaches of Marin County 30 miles northwest of San Francisco. A four-year study there showed that a one-time application of compost caused an increase in plant productivity that has continued ever since, and that the soil’s carbon content grew year after year, at a rate equivalent to the removal from the atmosphere of 1.5 metric tons of carbon dioxide per acre annually.

    Whendee Silver, an ecosystem ecologist at the University of California at Berkeley who is the project’s lead scientist, calculated along with a colleague that if as little as 5 percent of California’s rangelands was coated with one-quarter to one-half inch of compost, the resulting carbon sequestration would be the equivalent of the annual greenhouse emissions of nine million cars. The diversion of green waste from the state’s overcrowded landfills would also prevent it from generating methane, another potent greenhouse gas.

    Some scientists remain skeptical of regenerative agriculture, arguing that its impact will be small or will work only with certain soils. It also faces significant obstacles, such as a scarcity of research funding and the requirements of federal crop insurance, which frequently disqualifies farmers who plant cover crops….

    …. In a region [TX and OK] where rainfall is usually precious, some conventional soil has become so lifeless that it absorbs as little as half an inch of water per hour, Mr. Durham said, while regenerative fields can absorb more than eight inches an hour.

    Mr. Durham’s farmers are learning a lesson that resonates throughout human interactions with the natural world: People reap more benefit from nature when they give up trying to vanquish it and instead see it clearly, as a demanding but indispensable ally. Because of carbon’s climate change connection, we’ve been conditioned to think of it as the enemy, when in fact it’s as vital to life as water. The way to make amends is to put it back in the soil, where it belongs.

     

  6. Timing is key in keeping organic matter in wet cropland soils, new study finds

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    • Periodically flooded soils may actually lose organic matter at accelerated rate, a new report suggests.

    November 24, 2017 Iowa State University read full ScienceDaily article here

    ..The study found that timing plays a key role in how well wet soils retain organic matter. While soils with consistently high moisture content do retain organic matter over the long term, soils may actually lose organic matter during shorter spans of flooding. The findings have implications for agricultural fields that are poorly drained or flood for a few weeks of the year before drying out, Hall said. The study also shows that wetlands, thought of as a useful tool for conservation and carbon sequestration, may require consistent flooding to realize environmental benefits from organic matter accumulation….

    …”We found that periodically wet soils don’t necessarily protect organic matter from decomposition and may lead to losses, at least over a timescale of weeks to months,” he said.

    The study drew on research conducted in an ISU laboratory. The researchers took soil samples from a central Iowa cornfield and subjected the sample to various conditions before conducting chemical analyses.

    Hall said future research should widen in scope and include field experiments as well as laboratory-based work. He said he wants to test how various drainage techniques influence organic matter loss as well as pinpoint the length of time required for wet soil to realize environmental benefits….

    Wenjuan Huang, Steven J. Hall. Elevated moisture stimulates carbon loss from mineral soils by releasing protected organic matter. Nature Communications, 2017; 8 (1) DOI: 10.1038/s41467-017-01998-z

  7. Better managed cropland soil could trap as much planet-warming carbon as transport produces or ~18-20% of annual global emissions- study

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    • The extra carbon that could be stored from rejuvenated soil is equivalent to 3 to 7 billion tonnes/year of planet-warming carbon dioxide (of annual global emission of 35-40 billion tonnes/year)
    • The U.S. emits around 5 billion tonnes of carbon dioxide per year. So (emissions) equivalent of a major economy could be sequestered in soils each year with changes in farming practices
    • US has the highest total annual potential to store carbon in the soil, followed by India, China, Russia and Australia, if soil management is improved.
    by Thin Lei Win Tuesday, 14 November 2017 17:15 GMT  Read full Thomson Reuters Foundation article here

    Improving soil health in farmlands could capture extra carbon equivalent to the planet-warming emissions generated by the transport sector, one of the world’s most polluting industries, experts said Tuesday.

    Soil naturally absorbs carbon from the atmosphere through a process known as sequestration which not only reduce harmful greenhouse gases but also creates more fertile soil.

    Better soil management could boost carbon stored in the top layer of the soil by up to 1.85 gigatonnes each year, about the same as the carbon emissions of transport globally, according to a study published in the journal Nature. “Healthier soils store more carbon and produce more food,” Louis Verchot of the Colombia-based International Center for Tropical Agriculture, and one of the study’s authors, said in a statement.

    “Investing in better soil management will make our agricultural systems more productive and resilient to future shocks and stresses.”

    Using compost, keeping soil disturbance to a minimum and rotating crops to include plants such as legumes can help restore organic matter in the soil, Verchot told the Thomson Reuters Foundation….

    Robert J. Zomer, Deborah A. Bossio, Rolf Sommer & Louis V. Verchot. Global Sequestration Potential of Increased Organic Carbon in Cropland Soils. Scientific Reports 7, Article number: 15554 (2017) doi:10.1038/s41598-017-15794-8

    ABSTRACT: The role of soil organic carbon in global carbon cycles is receiving increasing attention both as a potentially large and uncertain source of CO2 emissions in response to predicted global temperature rises, and as a natural sink for carbon able to reduce atmospheric CO2. There is general agreement that the technical potential for sequestration of carbon in soil is significant, and some consensus on the magnitude of that potential. Croplands worldwide could sequester between 0.90 and 1.85 Pg C/yr, i.e. 26–53% of the target of the “4p1000 Initiative: Soils for Food Security and Climate”. The importance of intensively cultivated regions such as North America, Europe, India and intensively cultivated areas in Africa, such as Ethiopia, is highlighted. Soil carbon sequestration and the conservation of existing soil carbon stocks, given its multiple benefits including improved food production, is an important mitigation pathway to achieve the less than 2 °C global target of the Paris Climate Agreement.

  8. Huge carbon sink in soil minerals: New avenue for offsetting rising greenhouse gases

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    November 8, 2017  Washington State University read full ScienceDaily article here

    Soil holds more than three times the carbon found in the atmosphere, yet its potential in reducing atmospheric carbon-dioxide levels and mitigating global warming is barely understood. A researcher has discovered that vast amounts of carbon can be stored by soil minerals more than a foot below the surface. The finding could help offset the rising greenhouse-gas emissions helping warm the Earth’s climate…

    …Findings in one of two related papers demonstrate how the right management practices can help trap much of the carbon dioxide that is rapidly warming the planet...

    …Almost three-fourths of all carbon sequestered in the top three feet of the soil is affected by agriculture, grazing or forest management, Kramer and his colleagues report in the Annual Review paper.

    Earlier research by Kramer found that certain farming practices can dramatically increase carbon in the soil. Writing in Nature Communications in 2015, Kramer documented how three farms converted to management-intensive grazing practices raised their carbon levels to those of native forest soils in just six years. While cultivation has decreased soil carbon levels by one-half to two-thirds, the soils he examined had a 75 percent increase in carbon.

    …Knowing more about how soil stores carbon can open the door to new techniques that will entrain carbon deep into the soil while continuing to produce food and fiber….

    1. Marc G. Kramer, Kate Lajtha, Anthony Audfenkampe. Depth trends of soil organic matter C:N and 15N natural abundance controlled by association with minerals. Biogeochemistry, 2017; DOI: 10.1007/s10533-017-0378-x
    2. Robert B. Jackson, Kate Lajtha, Susan E. Crow, Gustaf Hugelius, Marc G. Kramer, Gervasio Piñeiro. The Ecology of Soil Carbon: Pools, Vulnerabilities, and Biotic and Abiotic Controls. Annual Review of Ecology, Evolution, and Systematics, 2017; 48 (1): 419 DOI: 10.1146/annurev-ecolsys-112414-054234
  9. The fingerprints of coastal carbon sinks- new technique to measure carbon in coastal wetlands

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    • researchers found that using diffuse reflectance spectroscopy, or DRS, normally used on dry soils, may be a more accurate and efficient method compared to more conventional approaches to determine carbon levels in mangrove soils.

    November 1, 2017 American Society of Agronomy read full ScienceDaily article here

    A new study highlights a technique that could be used to accurately measure levels of soil carbon in coastal carbon sinks, such as mangrove forests…

    …In the past, researchers have used the technique — diffuse reflectance spectroscopy, or DRS — to measure carbon in dry soils. “Few studies have tested it in coastal wetland or mangrove soils” …

    …Nóbrega and his colleagues tested DRS on soil samples from three mangrove forests in northeastern Brazil. They found that DRS may be a more accurate and efficient method compared to more conventional approaches to determine carbon levels in mangrove soils.

    …Nóbrega hopes to build a library of soil reflectance fingerprints for mangrove soils throughout the world. He doesn’t want to stop with mangrove soils, though. “Ultimately, we want to expand to other coastal environments, such as saltmarshes, seagrasses, and tidal flats,” he says.

    Eventually, it might be possible to equip a drone with the required sensors. “Then we could obtain vital information without disturbing sensitive ecosystems,” says Nóbrega. “We could monitor carbon levels in large, inaccessible areas.”

    Danilo J. Romero, Gabriel N. Nóbrega, Xosé L. Otero, Tiago O. Ferreira. Diffuse Reflectance Spectroscopy (Vis-Nir-Swir) as a Promising Tool for Blue Carbon Quantification in Mangrove Soils: A Case of Study in Tropical Semiarid Climatic Conditions. Soil Science Society of America Journal, 2017; 0 (0): 0 DOI: 10.2136/sssaj2017.04.0135

  10. Soil Restoration: 5 Core Principles

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    Christina Jones, PhD October 17, 2017 read full article in EcoFarming Daily

    Imagine there was a process that could remove carbon dioxide (CO2) from the atmosphere, replace it with life-giving oxygen, support a robust soil microbiome, regenerate topsoil, enhance the nutrient density of food, restore water balance to the landscape and increase the profitability of agriculture. Fortunately, there is. It’s called photosynthesis….

    ….It comes as a surprise to many to learn that over 95 percent of life on land resides in soil and that most of the energy for this amazing world beneath our feet is derived from plant carbon. Exudates from living roots are the most energy-rich of these carbon sources. In exchange for ‘liquid carbon,’ microbes in the vicinity of plant roots — and microbes linked to plants via networks of beneficial fungi — increase the availability of the minerals and trace elements required to maintain the health and vitality of their hosts (1,2).

    Microbial activity also drives the process of aggregation, enhancing soil structural stability, aeration, infiltration and water-holding capacity. All living things — above and below ground — benefit when the plant-microbe bridge is functioning effectively….Over the last 150 years, many of the world’s prime agricultural soils have lost between 30 and 75 percent of their carbon, adding billions of tons of CO2 to the atmosphere (3)….

    ….PRINCIPLES FOR SOIL RESTORATION

    1. Green is good — and year-round green is even better. Every year, photosynthesis draws down hundreds of billions of tonnes of CO2 from the atmosphere. The impact of this drawdown was dramatically illustrated in a stunning visualization released by NASA in 2014 (8). The movement of carbon from the atmosphere to soil — via green plants — represents the most powerful tool we have at our disposal for the restoration of soil function and reduction in atmospheric levels of CO2….
    2. Microbes Matter. A healthy agricultural system is one that supports all forms of life. All too often, many of the life-forms in soil have been considered dispensable. Or more correctly, have not been considered at all. The significance of the plant-microbe bridge in transferring and stabilizing carbon in soil is becoming increasingly recognized, with the soil microbiome heralded as the next frontier in soils research….
    3. Diversity is Indispensable. Every plant exudes its own unique blend of sugars, enzymes, phenols, amino acids, nucleic acids, auxins, gibberellins and other biological compounds, many of which act as signals to soil microbes. Root exudates vary continuously over time, depending on the plant’s immediate requirements. The greater the diversity of plants; the greater the diversity of microbes and the more robust the soil ecosystem….
    4. Limit Chemical Use. The mineral cycle improves significantly when soils are alive. It has been shown, for example, that mycorrhizal fungi can supply up to 90 percent of plants’ N and P requirements. In addition to including companions and multi-species covers in crop rotations, maintaining a living soil often requires that rates of high-analysis synthetic fertilizer and other chemicals be reduced to enable microbes to do what microbes do best….
    5. Avoid Aggressive Tillage. Tillage may provide an apparent quick-fix to soil problems created by lack of deep-rooted living cover, but repeated and/or aggressive tillage increases the susceptibility of the soil to erosion, depletes soil carbon and organic nitrogen, rapidly mineralizes soil nutrients (resulting in a short-term flush but long-term depletion) and is highly detrimental to beneficial soil-building microbes such as mycorrhizal fungi and keystone invertebrates such as earthworms….

    It is not so much a matter of how much carbon can be sequestered by any particular method in any particular place, but rather, how many soils are sequestering carbon. If all agricultural, garden and public lands were a net sink for carbon we could easily drawdown sufficient CO2 to counter emissions from the burning of fossil fuels.

    Everyone benefits when soils are a net carbon sink. Through our food choices and farming and gardening practices we all have the opportunity to influence how soil is managed. Profitable agriculture, nutrient-dense food, clean water and vibrant communities can be ours … if that is what we choose.