New Global Warming Remedy: Turning Rangelands into Carbon-Sucking Vacuums

By Glen Martin

Studies conducted on a ranch in the heart of Marin County and led by UC Berkeley researchers and alums seem to confirm what home gardeners have long suspected: Compost really can save the world.

That sounds hyperbolic, of course. But research led by Whendee Silver of Berkeley’s Department of Environmental Science, Policy, and Management concludes that a judicious scattering of finished compost on our rangelands could lock up gigatons of atmospheric carbon, preventing it from heating up the planet and contributing to such unpleasantness as prolonged drought, polar ice cap loss, sea level rise and ocean acidification.

Ap­ply less than an inch of com­post to 5 per­cent of Cali­for­nia’s ran­ge­lands, and you suck enough car­bon from the at­mo­sphere to equal the emis­sions of 6 mil­lion cars.

What kind of numbers are we talking about? If a quarter-inch to one-half inch layer of compost were applied to 5 percent of California’s rangelands, it would sequester 28 million tons of carbon from the atmosphere—the equivalent to the annual emissions of 6 million cars.

That certainly sounds too good to be true. And yet, the published papers and support in the scientific community indicate that it’s the real deal.

“This is fantastic science with proven benefits,” Paul Wright, director of UC Berkeley’s Energy and Climate Institute, wrote in an email.  “Not only for carbon reduction, but (for) soil quality, grazing land quality, and (soil) water retention.”

“It isn’t just about stopping global warming,” adds John Wick, the co-owner of Nicasio Native Grass Ranch, the site of the studies. “We can reverse it.”

Well, yes and no. Compost alone won’t save the world. Our salvation also depends on civilization cutting back on fossil fuel consumption. It’s not either/or. It’s both/and.

That said, a growing number of experts are coming to believe that composting rangelands could make a significant contribution. Wick says that the research grew out of concerns he and his wife, children’s book author and illustrator (and Caldecott medalist) Peggy Rathmann had about the state of the pastures on their 540-acre west Marin ranch. “When we bought the ranch, we were mainly interested in the natural beauty of the setting and the buildings that we intended to use for studios,” says Wick. “We wanted things to be ‘natural,’ so we arrogantly (ended the lease) of a young man who was grazing cattle on our property.”

Within a relatively short time, however, Wick and Rathmann noticed that the bovine ban had an adverse effect. Their rangelands were degrading, not improving;  invasive, non-indigenous grasses and forbs were replacing the native bunchgrasses and perennials. Further, the weeds were so thick that they were choking out brooding habitat for native ground-nesting birds.

So the couple hired rangeland ecologist Jeff Creque, who holds a master’s degree in range science from UC Berkeley, to look into the situation. Creque noted that California’s grasslands had evolved with great herds of ungulates, tule elk among them. These herbivores would typically graze an area intensely, then move on. This pattern resulted in the periodic “harrowing” (with hooves) and fertilizing (with dung) of the land, encouraging the lush growth of native grasses. Creque suggested that Wick and Rathmann re-introduce cattle to their property, and manage them in ways that mimicked the feeding patterns of the long-vanished herds of elk that once cropped the Marin savannas.

“When we did, the changes were dramatic,” Wick said. “We had native grasses and wildflowers coming back, and native birds were returning. You could just see our grasslands functioning at a higher state.”

But Creque wasn’t thinking only in terms of cows and invasive weeds when he signed on with Wick and Rathmann. He had been deeply involved in organic farming for years—and organic farming, as its name indicates, is all about carbon. Soil carbon, specifically. To a large degree, soil productivity is linked to the amount of carbon it contains. Carbon improves the tilth and water retention capabilities of soil, and it is the central element in Soil Organic Matter, that component of dirt that contains all the biological residues and byproducts that make plants grow.

The world’s soils also are a massive sink for carbon, storing exponentially more carbon than persists in the atmosphere as CO2 along with more potent greenhouse gases such as methane and nitrous oxide. That’s why Creque has long wondered: Can you jack up the carbon sequestration potential of rangelands? And if so, how? Compost seemed a promising avenue to Creque, but he wasn’t sure about the best way to proceed.

“John and I began talking about it, and he was very enthusiastic about using the ranch as a testbed,” says Creque. “But we had to address a few basic questions. First, are there any protocols that will actually work? And if any do work, how do we measure their effects? Further, what is the market for rangeland carbon? Could we generate enough interest among rangeland managers to make a difference?”

So Creque and Wick approached Silver, who’s an authority on the chemical exchanges that occur among plants, soils and the atmosphere.

The re­vital­ized ran­ge­lands turn in­to land­scape-scale va­cu­um clean­ers, suck­ing prodi­gious quant­it­ies of car­bon—up to 3 tons per hec­tacre per year—from the air.

“Dr. Silver agreed to work with us, but she was highly dubious,” recalls Creque. “She was by no means convinced that (carbon sequestration in soils could be significantly increased), and that it could be accurately measured if it did occur. That made her the perfect partner for us. Not only did she have the skill set we needed, but her skepticism assured that our research would be rigorously managed and the results thoroughly vetted.”

To get some baseline data, Silver led a study that compared soil carbon levels at 35 sites on beef cattle and dairy operations in Marin County. They found a range of carbon levels, but the sites that registered a lot of carbon had one thing in common: Ranchers and farmers had spread raw manure on the land. Those results were surprising, says Wick, because raw manure is known to emit prodigious quantities of greenhouse gases into the atmosphere. Yet somehow, carbon was getting down into the soil—and staying there.

How did they know? “Dr. Silver sent out samples to have them carbon dated, Wick explains.

In brief: Researchers use the rate of decay of a specific carbon isotope (Carbon-14) to determine the age of carbonaceous substances. In the case of the manured plots, researchers found traces of Carbon-14 linked to atmospheric releases of radioactive materials that occurred years ago; the isotopes were a meter deep.

“That means carbon was being deeply sequestered in a stable form, and it was somehow due to the manure applications,” Wick says.

If raw manure is good, they figured, compost should be better: Its carbon generally is in more stable forms than that found in raw manure, and doesn’t sublimate to the atmosphere as easily. So the researchers spread roughly a half-inch of compost on some test plots to see what would happen.

The results (confirmed by Silver) were pretty spectacular. Four years after application, 90 percent of the compost’s carbon was still in the soil, says Creque. Further, the computer models the team developed indicated carbon levels would remain high for 30 to 100 years due to that single application of compost.

But here’s the best part: most of the carbon didn’t come from the compost, it came from the atmosphere. The compost, it turned out, was a catalyst for a virtuous cycle.

“By increasing soil carbon, you’re increasing soil fertility and water retention capacity,” Creque says. “That results in more robust vegetation, which captures more and more carbon from the atmosphere. This carbon is stored underground in the roots, in residual dry matter (on the surface) and in enhanced populations of microorganisms in the soil.”

Analyses of the composted plots indicated they were sequestering from one-half to three tons of carbon per hectare per year as a result of the single application, says Creque. The revitalized rangelands essentially turn into landscape-scale vacuum cleaners, sucking prodigious quantities of carbon from the atmosphere.

That all looks good on paper (or pixels). But will it translate to the real world?

Will farmers and ranchers —the people who will actually have to go through the laborious and sometimes aromatic process of spreading compost on their lands—take to it?  Early indications are promising. Now functioning as the Marin Carbon Project, Wick, Creque and others, in conjunction with the Environmental Defense Fund and Terra Global Capital,have established protocols based on the research. Last month, The American Carbon Registry approved these procedures, meaning that ranchers who adhere to the protocols earn tradable carbon credits.

Why, then, isn’t every­body jump­ing all over this? A meth­od­o­logy that can re­verse run­away at­mo­spher­ic car­bon while churn­ing out ham­burgers is the plan­et’s Golden Tick­et.

Funding for the research and development of the protocols was provided the U.S. Department of Agriculture, the State Coastal Conservancy, and the 11th Hour Project, a program supported by the Schmidt Family Foundation

Next step is a $20 million grant application pending before the USDA for the Bay Area, says Torri Estrada, policy director of the Marin Carbon Project and also a Cal alum who has lectured in the Department of Environmental Science, Policy, and Management. “And we’re working with a number of county resource conservation districts—Marin, Sonoma, Mendocino, Santa Barbara, Napa, Tehama, Butte and Modoc—to help willing landowners implement the protocols.”

The protocols went through a rigorous vetting process with the American Carbon Registry, says Kyle Hemes, a program associate at the registry. That included a month-long public comment period and a blind peer-review process that involved multiple rounds of input from participants.

“The protocols were approved two weeks ago and are now up on our website,” says Hemes. “Other projects are now free to use them to document greenhouse gas removals.” The registry issues one credit for each ton of carbon that is sequestered. Right now, credits generated by the rangeland protocols can only be used for the “voluntary” carbon market. That’s not necessarily a small exchange; firms like Google buy lots of voluntary carbon credits. But the so-called compliance market—dictated by legislation such as the California Global Warming Solutions Act of 2006 (AB32)—is much larger.

“The state Air Resources Control Board is the implementing agency for AB32, and they’ve approved five project types for the compliance market,” says Arjun Patney, policy director at the Carbon Registry. “Two involve forestry, one deals with power generation using methane from livestock manure, one deals with the destruction of old CFC refrigerants, and the last addresses mine methane capture.”

But there’s certainly reason for hope that the rangeland protocols can join this list, says Patney.

“Right now AB32 applies to power generation and heavy industry,” he says. “But next year, transportation joins the list. So the carbon credit market will only grow.”

Why, then, isn’t everybody jumping all over this? A methodology that can reverse runaway atmospheric carbon while churning out hamburgers is the planet’s Golden Ticket. But the lumpenprole press has yet to take notice.

“We haven’t really been focused on publicity,” says Estrada.

The findings also run counter to conventional wisdom among some climate change activists who tend to view cattle—major producers of methane—as a part of the problem. This research suggests that rangelands, essential to cattle production, could also be a major tool for addressing climate change.

Will there be enough com­post to go around? Can old cof­fee grounds, fruit rinds and the leftover rigatoni go from sol­id waste prob­lem to blue chip as­set?

Some ranchers and farmers themselves may feel uneasy about having their lands identified as a critical carbon bank—a move that could raise the possibility of government regulation.

But the findings also beg the question: If this thing really takes off, will there be enough compost to go around? Will old coffee grounds, fruit rinds and the leftover rigatoni from the Italian bistro on the corner go from solid waste problem to blue chip asset.

“It may well be that these programs could be limited to one degree or another by the availability of raw material for compost,” acknowledges Estrada. “But I don’t think it’s a bad thing if (organic waste) becomes valuable because it’s key to an effective carbon sequestration program. That helps solve two problems—solid waste disposal and carbon emissions.”

Perhaps here, at the end of all this happy talk, it’s appropriate to reiterate that previously mentioned caveat: Yes, it’s apparently a very good thing to turn all our kitchen slop into dark, rich compost and spread it on our rangelands. But we also have to stop incinerating the residues of dead dinosaurs.

“It’s pretty clear these protocols have the potential to reverse global warming,” concludes Creque. “But that won’t happen if we continue burning fossil fuels at the current rate. That’s also pretty clear.”

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Every gram of Soil-C holds 8 grams of H2O, One ton per acre per year adds 8 tons of water, 2,152 gallons each year.
Compost is also a fertilizer. If you give a plant some fertilizer, it will use carbon from the air to put roots into the soil. As a gardener, I think the biggest benefit of compost is to make it easier for roots to grow, and to hold moisture, but that generally involves working the compost into the soil. The other interesting aspect of compost or manure is that the microbes that grow in it help release minerals from the soil that plants cannot otherwise get at. Plants have symbiotic associations with soil microbes. So compost and manure, if you can get enough of it, is better than synthetic fertilizer. But we are not going to get enough of it to cover a big percentage of range land.
This is a nice start, but it only scratches the surface. Biochar (or biocarb) is refined compost, with the volatiles driven off by heat in a pyrolysis cooker and distilled into useful products, such as non-fossil drop in replacements for diesel, gasoline and natural gas. The merits of biochar include longer carbon sequester — biochar lasts millennia, compared to compost’s often annual lifespan — while amending soil in more ways than compost does. It is lighter to transport, having everything but the carbon removed until it arrives on site for mixing with native soils, and there are dozens of other uses for clean biochar compared to compost’s one single application. It’s true not all soil benefits entirely from biochar amendment, but that is also true of compost: most compost is a mistake; almost anything but dry leaf matter mulch is better used as feedstock for worms than for the slower and weaker microbes that break it down, and all compost or worm product produce methane off gas, a powerful GHG that breaks down eventually to CO2 in air anyway. Composting pretty much only beats burning, in terms of how fast it gets the carbon back into the atmosphere, and on the whole skipping the methane release step might even make burning the less GHG intensive route, depending on conditions. Beside biochar, hugelkultur — shifting agriculture from flat furrows to deep mounds and troughs based on buried biomass to conserve soil moisture — makes more productive land with less water and far more carbon sequestration. Clean paper, mixed compostables, logs and bamboo purposely grown to sequester in this way, form natural water-and-carbon retaining berms covered in a relatively thin layer of soil for planting. And the plants? Choose deeper-rooting varieties to drive carbon deeper into the soil. There are plants that root sixty feet deep or more; most cultivars preferred by industrial planters are like the wasteful lawn plants with roots an inch in the soil or less, that effectively lock carbon in that inch. Replace the lawns of suburbia with deeper rooting field plants (that often look just the same on top) and you multiply the sequester power of every lot. But all of this is just Dyson’s Folly, if we do not end fossil waste dumping in air. It takes a new Amazon Rainforest of land area doing all of the above biochar, hugelkultur and deep rooting every seventeen years just to keep up with how much CO2 is added to the carbon cycle from fossil by lucrative unpaid-for dumping.
Optimizing the type of grazing lands, the changing climate and balancing soil health is an old concern for ranchers, this is a great paperback on a sensible & proven approach likely much better than mechanically spreading compost, not that some lands wouldn’t respond well to doing that but the carbon footprint of moving than many tons of anything implies it won’t be sustainable. Nathan Sayre, “The New Ranch Handbook: A Guide to Restoring Western Rangelands”, 2001, The Quivera Coalition, Santa Fe, NM; ISBN 0-9708264-0-0
I love this. There are also huge parts of east and southern africa, where soil is degraded by overgrazing. If we can capture carbon in soil through better grazing practices and cheap fertilization. Not only will be sink carbon but uplift the the lives of the people who eek their living out of the poor soils.
the Biochar Journal’s Kelpie Willson has written the single best article I’ve ever read in over 8 years of research concerning; How Biochar Works in Soil http://www.biochar-journal.org/en/ct/32 Kickstarting Compost with Biochar If you look at a list of things biochar is supposed to do in soil, you’ll find it is very similar to lists you see for compost. Both biochar and compost are said to provide these benefits, taken from various claims made by biochar and compost manufacturers: Improves tilth and reduces soil bulk density Increases soil water holding capacity Becomes more stable by combining with clay minerals Increases cation exchange capacity (CEC - the ability to hold onto and transfer nutrient cations: ammonium, calcium, magnesium, and potassium) Improves fertilizer utilization, by reducing leaching from the root zone Retains minerals in plant available form Supports soil microbial life and biodiversity Helps plants resist diseases and pathogens Helps plants grow better in high salt situations Adds humus carbon to the soil carbon pool, reducing the atmospheric carbon pool If compost really can do all these things, why do we need biochar? The answer is twofold: First, unlike biochar, compost is quickly broken down by microbial action in soil over months to at most, decades, depending primarily on climate. Biochar lasts at least ten times longer in most soils. Recently, I called a California agriculture extension agent with a question about adding compost to fields to improve water holding capacity. I was told that because of the hot climate, at least two applications a year are needed to maintain enough soil organic matter to make a difference in water holding capacity. Aside from the expense of applying that much compost, there is simply not enough compost available to support such large application rates. Second, biochar has important synergistic effects when added to compost. Researchers find that biochar makes faster, more nutrient rich, more biologically diverse and more humified, stable compost. Below, I examine several of the most important biochar effects and summarize some recent research results.
The DeLonge study on the Marin Carbon website is materially defective in both its assumptions and its greenhouse gas (GHG) conclusions for the Marin Carbon Project: http://link.springer.com/article/10.1007%2Fs10021-013-9660-5 A Lifecycle Model to Evaluate Carbon Sequestration Potential and Greenhouse Gas Dynamics of Managed Grasslands (DeLonge et al) concludes with a clear management recommendation to apply compost to rangelands in beef production, which represent the vast majority of California rangeland acres. Yet the DeLonge study intermixes dairy issues with beef issues and results in a contradictory mis-mash of conclusions. The study assumes that increased forage resulting from compost application will result in decreased need for supplemental forage and beneficial GHG impacts. But the need for supplemental forage in beef operations, for which forage availability is a limiting factor, is largely seasonal. Thus an increase in seasonal forage on beef operations will likely trigger an increase in stocking rates and an increase (not a decrease) in the need for supplemental forage to service the increased stocking level. If, as the study concludes, compost application will double forage on beef acreage, then it is also reasonable to conclude that doubled forage will result in doubled beef cattle numbers. But any doubling of the enteric emissions from beef cattle will quickly (within a single year) overcome the modest increase in soil carbon from compost. Enteric emissions for cattle are a really significant GHG contributor and have been estimate to equal the GHG impacts from transportation. Thus any doubling of fodder that triggers a doubling of beef cattle cannot be ignored. Further, compost application to beef acreage also favors non-native annual grasses over native perennials, which can sequester much more carbon per acre than composted soil. Yet the DeLonge study ignores both the strong likekhood of increased enteric emissions from more beef cattle and impacts to native sequesterers. This not just undermines, but completely contradicts the GHG claims of the Carbon Project’s proposed application of compost to beef acreage. However, some benefits of applying compost to dairy acreage may be real but are greatly overstated. DeLonge did not study the fodder effects of dairies going from liquid manure application to compost application (all the test sites were on beef ranches). DeLonge assumes that however the nitrogen (N) content is increased, fodder will be increased roughly proportionately. But if so, then substituting compost N for slurry N on dairies would yield little to no extra fodder and thus would not reduce the need for supplemental food on dairies. Further, exporting nitrogen from dairy to beef ranches (by the logic of the DeLonge study) would simply transfer productivity location without any overall systemic gain. The DeLonge study also assumes the worst case scenario of liquid/slurry application and ignores that some dairies apply solid manure. As the “Results” on DeLonge page 969 make (less than) clear, offsets from manure pond and landfill avoidance account for 26 of the net 22.6 reduction. In other words, the production and application of compost actually increases GHG by 3.7. But dairies that manage solid manure don’t store the liquid manure that creates methane (CH4) and thus don’t have the same GHG impacts. Yet Table 2 compares compost only to slurry and chemical fertilizers. Compared only to this worst case of slurry, composting looks good. Thus the DeLonge study ignores any comparison to solid manure management, which would eliminate compost’s slurry offset. Further, DeLonge also ignores that the E.U. and most U.S. states ban compost as Alternative Daily Cover for Landfills. A similar ban has been suggested for CA, which (along with a reduction in liquid manure management) would eliminate all of DeLonge’s theoretical composting offsets. There may still be considerable value in compost used to replace chemical fertilizers used to grow crops, including the supplemental food for cattle. Composting on dairies likely has other values (retaining moisture and reducing runoff) compared to liquid manure management. And composing probably does increase carbon sequestration compared to liquid manure management. But other carbon farming techniques for beef and dairy operations could also be incentivized with Carbon Credits including riparian restoration, no-till silage, native grass restoration, and the restoration of forests cut down to graze cattle: http://www.energy.ca.gov/reports/CEC-500-2004-068/CEC-500-2004-068F.PDF All of these GHG reduction options need to be fairly compared to each other, rather than siloed and compared only to a worst-case scenario that is being phased out. The assumptions in this DeLonge study only produce positive outcomes for compost on beef acreage by ignoring contradictory factors. Thus DeLonge study, perhaps inadvertently, creates a green patina over what is really a substantial potential economic benefit for the beef industry and a potential GHG disaster for everyone else. And thus the sweeping conclusions of the Marin Carbon Project are at best questionable. There is almost certainly value to compost made somehow and applied somewhere, but decidedly less than can be justified by the beef acreage repository asserted by DeLonge.
Compost? From what source? “Some manures are contaminated with hormones, antibiotics, pesticides, disease organisms, heavy metals, and other undesirable substances. Many of the organic compounds, pathogens, protozoa, or viruses can be eliminated through high-temperature aerobic composting. Caution is advised, however, as some disease causing agents, e.g. Salmonella and E. coli bacteria, may survive the composting process. Manure and compost testing is available through commercial labs and is recomended in situations where there is any doubt about the purity of manures. Manure and compost testing is available through commercial labs and is recomended in situations where there is any doubt about the purity of manures. Manure testing is required by the European Union and Canadian standards.” http://www.extension.org/pages/18628/managing-manure-fertilizers-in-orga... What would the US standards be, if the US had standards? I’m sure these issues have been thought about, and just weren’t included in the press release and public articles that focus on the positive side. But they should be talked about and the material tested and records kept.
I know we can get around a number of these problems by planting trees everywhere in the world and thereby creating new solutions.
There is a smarter and better way to sequester carbon from the air: Plant trees on our barren Bay Area hills (pine, redwood, etc.). That will not only suck up carbon gas, it will also give us back oxygen and freshen the air. It will attract moisture and rain. It will stabilize the soil and prevent landslides. It will beautify our landscape. It will keep us cooler in the summer and warmer in winter. It will create some jobs too! Do I need to keep going?
I would suggest that “planting trees” is a major simplification of the problem now with biomes becoming ecotones changing from warming. Trees can’t walk so rely on animals & winds to spread their seeds, this has limits to dispersal speed and many are already isolated from “moving” to their climate, such that foresters are already planting species where the new climate will match what they survive in today. … In other words you must plant what’s coming, not what’s there now in a lot of places. This is a video on this subject with details worth watching for those considering reforestation as a panacea, to be realistic nothing matters until fossil emissions are zeroed, that’s what the geophysics demands, the rest is fantasy, you can’t fix it with reforestation or geoengineering which is being done to artificially keep atmospheric global temperatures from rising as they should. … All that means is that the ocean is taking up more heat because the hot air is cooled by the ocean, the geoengineering if anything is making it worse, it doesn’t affect the megatons of carbon going into the troposphere continuously and guarantees disaster when it’s stopped from a rapid heating, this is well spoken of by many in the field. … Connie Barlow speaking with decades of work in this field, bookstore talk, 45-minutes: http://www.youtube.com/watch?v=wq-C4v-hVpY
Connie Barlow was great and supported by this recent research. The late Pleistocene to Holocene boundary shows a prestigious pedogenesis, the loess–paleosol sequences of the central and northern Great Plains record a broad peak of high effective moisture, a pedogenesis we can emulate with the bio-remediation techniques we advocate as the only economic way to reverse climate change.. The new research concerning the ecologically limiting effects of Phosphorous caused by the loss of the Mega-Fanua means we have never seen the true vigor that forest & grass lands could be. That what we now see as “pristine” systems are but a shadow of their primary production potential. The Pleistocene megafauna extinctions resulted in large and ongoing disruptions to terrestrial biogeochemical cycling at continental scales, switching off this natural nutrient pump by a massive 98%. The megafauna diffused sodium inland and also reduced concentrations in plants near the coast. The Trees that Miss the Mammoths https://fs.usda.gov/Internet/FSE_DOCUMENTS/fsbdev7_016050.pdf The legacy of the Pleistocene megafauna extinctions on nutrient availability in Amazonia http://www.nature.com/ngeo/journal/v6/n9/full/ngeo1895.html?WT.ec_id=NGE... Are Nutrient Limitations a Consquence of the Pleistocene Megafauna Extinctions? http://oxfordmegafauna.weebly.com/4/post/2014/03/chris-doughtyare-nutrie...
I do not see why one or the other needs to be chosen. You can plant trees, but if the land is barren the seed won’t take. This is some fantastic science proposed by Jeff Creque and John Wick indeed and the results are astonishing. This puts the idea “compost is good” into hard fact and provides incentive for people to collect green waste and turn it into compost. A strategic development would tackle two demanding environmental issues - carbon emissions and solid waste. Composting green waste addresses the carbon issue from another standpoint - food waste and garden waste constitutes for almost 1/4 of the United Kingdom’s solid waste and therefore for tonnes of carbon emissions, that could have been avoided had that organic green waste been composted. However, as the article points out, it is hard to depend on gardeners’ and farmers’ motivation, as after all they are the ones who have to go through the process of collecting and dispersing the compost. As a green waste clearance professional I can testify that people need time to create the habit, but are very responsive once properly convinced. That is why I believe your research and publication needs more publicity, more attention. I am working on convincing my company, Fantastic Waste Removal, to cite your research on your garden waste collection page. I sincerely hope that the copyright-holders wouldn’t mind. S. G, http://www.fantasticwasteremoval.co.uk/green-waste-clearance/
Hi Gordon, Your comment is an important one, and you are calling out important limitations in the study. However, I have one issue with your critique. You say, “If, as the study concludes, compost application will double forage on beef acreage, then it is also reasonable to conclude that doubled forage will result in doubled beef cattle numbers.” To which I say, wait, hold on, what? That’s a massive assumption! Is it really reasonable to conclude that doubling forage on such land will double cattle? I am not an expert in beef cattle stock dynamics, but presumably stocking decisions depend on many factors including global prices, water availability, capacity of transportation and other stockyards that limit production, and regional competition. And there may be other biological constraints on cattle that limit stocking density apart from forage (this I’m less sure about). Either way, what if we assume that increased forage doesn’t linearly increase cattle density? Or that there are concurrent efforts to shift market incentives away from strictly increasing beef production? Under such circumstances, the impacts of composting seem more important, and I am not sure that your critique remains as damning. PS - I believe we crossed paths at Berkeley back in ’08 in a Molecular Ecology course - if so, good to cross paths digitally again!
Rangeland ecosystems cover approximately one third of the land area in the World. What if that vast domain could be utilized to combat climate change, and ranchers could get paid for land management practices that keep more carbon in the soil and enhance production? Many challenges remain for carbon storage in rangelands on a large scale. Meanwhile, the science shows that putting compost on pastures, at least in some parts of California, can provide significant benefits to the climate as well as to ranchers. This whole system of using nature to try to help slow global warming is in the exploratory phases. But people are definitely taking the steps to move forward with this. Ben Johnson - http://www.rubbishplease.co.uk/

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