New study settles long-standing debate: Does agricultural erosion create a carbon sink or source

In new research published today in the European Geosciences Union journal Biogeosciences, two scientists address the soil organic carbon erosion paradox

Peer-Reviewed Publication


Schematic representation of the effect of water erosion and deposition on soil OC stabilization and loss processes

Over the last decade, researchers have sounded the alarm on soil erosion being the biggest threat to global food security. As world governments moved to implement soil conservation practices, a new debate began: does agricultural soil erosion create a net organic carbon (OC) sink or source? The question is a crucial one, as carbon sinks absorb more carbon than they release, while carbon sources release more carbon than they absorb. Either way, the answer has implications for global land use, soil conservation practices and their link to climate change.

In a new study published today in the European Geosciences Union journal Biogeosciences, two researchers show that the apparent soil organic carbon erosion paradox, i.e., whether agricultural erosion results in an OC sink or source, can be reconciled when we consider the geographical and historical context. The study was the result of a collaboration between UCLouvain, Belgium and ETH Zurich.

The organic carbon cascade
Early studies assumed that a substantial fraction of soil organic carbon that is mobilized on agricultural land is lost to the atmosphere. They concluded that agricultural erosion represented a source of atmospheric CO2, which led to the notion of a win–win situation: soil conservation practices that reduce erosion result in healthier soils AND a large carbon sink.

However, more recent studies have challenged this assumption and suggest a different pathway for the eroded organic carbon. They propose the concept of the “geomorphic OC pump” that transfers organic carbon from the atmosphere to upland soils recovering from erosion to burial sites where organic carbon is protected from decomposition in low-mineralization contexts. Along this geomorphic conveyor belt, the organic carbon originally fixed by plants is continuously displaced laterally along the earth’s surface where it can be stored in sedimentary environments. These studies argue that the combination of organic carbon recovery and sedimentation on land could capture vast quantities of atmospheric carbon, and so erosion may in fact represent an organic carbon sink.

“We demonstrate how these two competing views can exist at the same time and so this study offers an understanding of differences in perspective,” explains Kristof Van Oost from the Earth & Life Institute, UCLouvain.

Seeing the full picture for the first time
Johan Six from the Department of Environmental Systems Science, Swiss Federal Institute of Technology, and ETH Zurich says these latest findings are a first account of how all the different carbon dynamic processes induced by erosion interact and counterbalance each other in determining the net carbon flux from terrestrial environments to the atmosphere.

Six and Van Oost conducted a comprehensive literature review spanning 74 studies. Six explains the reason for the conflicting assumptions from previous studies. “We noticed that the perceived paradox was mostly related to not having considered the full cascade of carbon fluxes associated with erosion. This led us to thinking that it would be good to explain the complexity of the full carbon cascade.”

At the very centre of this paradox – they realised – is the fact that water erosion-induced processes operate across temporal and spatial scales, which determine the relationship between water erosion and organic carbon loss versus stabilization processes. Together they conceptualized the effects of the contributing water erosional (sub)processes across time and space using decay functions.

Timescales reconcile the paradox
Both researchers found that soil erosion induces a source for atmospheric CO2 only when considering small temporal and spatial scales, while both sinks and sources appear when multi-scaled approaches are used.

At very short timescales (seconds to days) erosion events shift a portion of the soil organic carbon from a protected state to an available state where it mineralizes to gaseous forms more rapidly. In contrast, studies considering erosion as a sink for atmospheric carbon typically consider longer timescales at which the geomorphic OC conveyor belt is operating.

The researchers emphasize the need for erosion control for the many benefits it brings to the ecosystem but recommend cross-scale approaches to accurately represent erosion effects on the global carbon cycle.

Looking to the future, Van Oost concludes, “Our insights into the effects of soil erosion on carbon storage are mainly derived from studies conducted in temperate regions. We now need new research on erosion effects in marginal lands but also tropical regions.”






Literature review


Not applicable


Reconciling the paradox of soil organic carbon erosion by water




The contact author has declared that neither of the authors has any competing interests.

From EurekAlert!

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Curious George
February 19, 2023 2:11 pm

Did anybody ever propose that erosion was beneficial?

Reply to  Curious George
February 19, 2023 5:20 pm

Without erosion rebuilding the Mississippi marshes, the Mississippi delta is fading fast.

Tim Gorman
February 19, 2023 3:11 pm

I often wonder if any of these “academics” ever get out and talk to people actually living on the land.

My house is located in an old pasture with waterways to handle surface runoff. I am surrounded by corn fields and soybean fields, also with waterways to handle surface runoff.

All of these waterways feed into what we call tail-water pits at various locations. In essence they are shallow ponds. Most of the erosion winds up silting in these tail-water pits that need to be dug out and reformed over the decades. None of this erosion get exposed for a very long period in order to push CO2 into the atmosphere. The CO2 in the erosion winds up at the bottom of shallow ponds or as top soil from being dug out of the pits.

I’ve seen this all over the US, from Texas to North Carolina, to Oregon and Washington, and to Nebraska and South Dakota.

Is the rest of the world done differently?

Reply to  Tim Gorman
February 19, 2023 5:29 pm

I often wonder if any of these “academics” ever get out and talk to people actually living on the land.

They don’t talk to the little people because they went to university. Unfortunately, these days uni is where rationality and wisdom go to die.

Mike McMillan
February 19, 2023 3:11 pm

As long as people gotta eat, farmers are gonna farm, so sink or source doesn’t much matter.

I note without comment that three months after it became apparent that the Russian invasion of Ukraine was going to seriously cramp world, and especially African, grain supplies, Joe Biden mandated an increase in fuel ethanol, which pulled a lot of U.S. corn off the food market.

Warmistas – 1, humanity – 0.

They don’t care. They just don’t care.

Rud Istvan
Reply to  Mike McMillan
February 19, 2023 6:02 pm

MM, sorry to counter your quasi opinion with some facts. I have owned a large Wisconsin dairy farm for decades. We used to plant corn. Crush it, and use it as an inefficient dairy alfalfa supplement. Lots of undigested crushed corn to feed the ruffed grouse and wild turkey in the pastures. No more.

We now send all the ~41%’dry weight’ (8%moisture) corn to be made into ethanol, receiving back about 27% ‘dry weight’ distillers grain—a protein enhanced (from yeast) ideal ruminant roughage supplement to alfalfa. As a result, we plant less alfalfa and more corn. We, and our dairy cows, are both better off than before.

Now, this is with a blend wall of 10% based on octane and smog requirements nationwide. Anything more I agree is just a farm boondoggle.

Mike McMillan
Reply to  Rud Istvan
February 19, 2023 11:13 pm

The only corn ethanol back when I was farm handin’ could get you locked up by the revenoors. ADM was just getting into corn syrup big time.

What were you using to dry the corn to 8%? Carbon-neutral biomass? That’s about twice as dry as what the elevators took. Oh, if anybody needs a used dryer, I got one. Think it ran on propane. The electric motors were nuclear powered.

Reply to  Rud Istvan
February 20, 2023 1:08 am

Energy to make ethanol is higher than energy from ethanol, with the exception of some high efficiency plants. It is a government mandated boondoogle. Use your corn to make moonshine whiskey instead. That’s where the big money is.

Ethanol contains less energy per gallon than gasoline. Denatured ethanol (98% ethanol) contains about 30% less energy than gasoline per gallon.

Reply to  Richard Greene
February 20, 2023 3:22 am


joe x
Reply to  rovingbroker
February 20, 2023 4:49 am

source? if you have a flex fuel vehicle, go and fill it up two or three times with e85 and monitor you mpg.

observed reality is the best educator.

Loren Wilson
Reply to  rovingbroker
February 20, 2023 1:27 pm

Per a reviewed database of physical properties, we have the heat of combustion of n-octane (a nice representative for gasoline) = -44421 J/g. Its density is 0.7027 g/cc at 25°C. For ethanol, we have the heat of combustion of -26808 J/g, and its density is 0.7859 g/cc. Multiply the heat of combustion by the density to give the energy per cc. This gives -31214 J/cc for n-octane and -21068 J/cc for ethanol. therefore, ethanol has 67% of the energy per cc (or gallon) as n-octane. The bigger point is that it takes a great deal of energy to convert corn into ethanol and then remove all the water. No one would add it to gasoline unless there was a government mandate or the price of gasoline was $5 a gallon.

Reply to  Loren Wilson
February 20, 2023 6:17 pm

And don’t forget that if you want to buy ethanol free gas, for your ATVs or other small engines, you are charged MORE due to hidden taxes.

Much like the upcharges on ICE autos from manufacturers buying CAFE credits from Tesla and other electric only car manufacturers.

First day of new Rep resident, executive order requiring all corporations selling anything to the US government to list ALL taxes and costs due to federal mandates such as the above, on the pump, or new car sticker, etc. including all the subsidies for electric vehicles. No one knows this stuff.

Reading the USEIA page it states B2 is only 2%, and B5 is 5%, but that is BS, because B”2″ is allowed “up to 5% now.

IIRC Brandon increased that to 10% with an executive order but I cant find that now, but would any search engine allow that to be found.

Almost everything that costs you mileage per gallon and miles per $ in operating your ICE vehicle is hidden.

But you sure do know how many calories in a Happy Meal!

I'm not a robot
February 19, 2023 3:37 pm

We don’t understand the carbon cycle. Trust us on the effects of CO2 on climate.

February 19, 2023 3:45 pm

“Mr. Beel ” Gates admits his carbon footprint is….gigantic…..but but but….he offsets it, see? Mr. Beel uses aviation fuel made from plants….uses an EV…..buys carbon offsets….whatta guy……Mr. Beel is savin’ duh whole world.

February 19, 2023 3:58 pm

As long as we live in a world with water and wind, there will be erosion.

Reply to  doonman
February 19, 2023 4:43 pm

“Did anybody ever propose that erosion was beneficial”
Yes, but this is another topic that has been overrun to some extent by the numerically challenged. I recall studies here in Australia that gave an average accretion rate of 1cm per hectare per annum on north-eastern agricultural lands. It has been noted on small residential properties. Simple domestic habitation for a decade or so tends to show accretion, such that the gradients of new residential lots was changed from 1:400 to 1:200 to reduce the effect. Erosion can be a problem, but lack of erosion because of weirs in river systems and breakwaters or armouring along shorelines, leads to beach erosion because the long-shore drift is interrupted. When there has been 800mm of rainfall over 18 hours then there will certainly be, and there always has been, massive run-off of sediment. Mangroves tend to trap a lot of this. Difficult to determine what effect mangroves have on CO2 because they absorb it (from dawn to noon) but they also trap flora and fauna debris that decays spectacularly when the heat rises.

February 19, 2023 4:42 pm

Consider the Nile , or any other river delta as the product of erosion. As my geology lecturer used to say;”without erosion nutrients would be in dire shortage.”

February 19, 2023 5:22 pm

Smart guy, but he can’t be allowed to just be a soil scientist. Soil scientists are indeed some of the best educated and equipped to research and understand the biosphere, because soil is the process-rich interface between a dynamic atmosphere and geologic processes. Soil scientists are also positioned to develop and devise better means to maintain soil chemical, physical and biological health, and teach important, practical findings to farmers, ranchers and urbanites.

However, to survive in today’s academy and get research money, he has to give a nod to climate change. His CV and this paper described in the press release are laced with “global carbon cycle” and “greenhouse gases.” The university marketing and communications office who undoubtedly authored this piece also wants to trumpet and overhype what his paper actually says and finds. I see this regularly at my own universities, especially where advancing the “narrative” pushes the right buttons. The idea that his research is the first of its kind is ludicrous, and he himself would probably be quick to say that his findings may be useful but far from the last word. Research advancements are by nature slow and tedious, moving forward in baby steps. He also manages to slip in the important message _ soil conservation is a good thing, irrespective of alleged effects on climate.

Rud Istvan
February 19, 2023 5:49 pm

For over forty years I have owned a Wisconsin ‘Uplands’ big diary farm. Hilly and rocky, so soil erosion was a big deal. We now avoid it almost entirely using three ways:

  1. Steeper slopes are now all grass pasture or woodlots.
  2. Shallow slopes are all contour farmed. We have several contours up to and beyond the high point half mile long ridge. Works great for crop rotation.
  3. Shallow slope contours are also only tilled 1/5 years. Three in alfalfa, tilled, two in beans or corn seed drilled using no till second planting.
Peta of Newark
February 19, 2023 5:59 pm

10 sigh

20 <wrap up warm>
deserts are cold places and to suggest these little poppets already inhabit one is understatement.

Well that was a lie: They inhabit many deserts not just one, Climate Science being the most notable. Rather laughable but couldn’t be more serious, an expanding physical desert created they one they demonstrate here: a Knowledge Desert

It gets worse in when I say ‘expanding’, everyone thinks of acres, square miles, Rhode Islands or even Australias.

Yes and no.
Deserts exist in 4 dimensions – there is no escape once you’ve made one and that’s just the real actual physical ones
The virtual ones created inside eroded minds and computers (same things and as here) are massively more, as they themselves say, ‘complex’ – impossible to escape no matter how much tax you pay.

So we hereby witness flat-landers trying to describe the erection of a telegragh pole in their dreary, tedious and boring world

While they level ‘Flat Earth’ charges against skeptics


PS I followed one of the links and whichever one talked of Carbon release of ‘up to 10e12 Pg’
Simply running a plough over an old cow-pasture triggers the release of 10 tonnes of CO2 per acre per year while it lies fallow = 10e10 Pg CO2 per year

Running a chainsaw over ancient forest e.g. to feed Drax or to plant Biodiesel will release CO2 at 10 times that rate (Latitude dependant) for 10, 15 or even 20 years afterwards – NOT incl what was in the trees.

Had to chuckle where they talk of ‘subsoil circulation’
There is no circulation inside subsoil – else it wouldn’t be subsoil

Reply to  Peta of Newark
February 19, 2023 8:11 pm

Peta, do you convert all mass quantities to Petagram 🙂
1hectare = 100m x 100m = 10 000 sq m.
At 10 tons/year,every square meter releases 1kg (2 pounds plus) of CO2 a year.
At 1.8kg/m^3, that’s just over half a cubic meter of pure CO2. Multiply by 100 for the “up to” crowd.
Has this been demonstrated, or does it come from somebody’s colonic test tube again?
As for subsoil circulation, there are enough microbes to account for the theory that oil is a byproduct of continuing biological processes, but I doubt these fabulists are talking about that, as they seem blissfully unaware of the role of soil microbes anyway.Which makes me wonder what worth are these numbers on millions of hectares where the soil biology has been poisoned by Roundup and all the other chemistry-set goo of factory farming. How much carbon is in there anyway?
The carbon argument has long devolved into the realms of that complex science to explain the weird loops the planets make in their orbits around the earth. I forget the term…

Reply to  Peta of Newark
February 20, 2023 11:26 am

Peta, “Deserts exist in 4 dimensions – there is no escape once you’ve made one and that’s just the real actual physical ones”. You do know that the Sahara has been alternately a desert and savanna several times in the last couple of million years?

February 19, 2023 8:37 pm

Soil erosion is the creation of desert, full stop.

The organic soil sponge rendered to dust.

Dr. Jimmy Vigo
February 19, 2023 8:41 pm

Nice piece of info! I shared this in my blog site, the pictures I took from the text are omitted here.

We have shared before the thought that the climate change agenda seriously lacks of a lot of technical testing, data and concrete results. I have mentioned before that what is called the carbon cycle is a very poorly understood issue regarding the interactions of carbon in plants, soils, water bodies and the atmosphere. It is important to point out that 1) this is mostly an issue of the field of environmental chemistry, 2) therefore, there is a lot of chemical reactions involved in transforming carbon from one chemical form into others in order for carbon to move in the environment. That is, this means that carbon in the atmosphere does not have the same chemical composition than when it is in soils, water bodies, plants, etc.; this is very complex.

Check out this new article of about 74 European studies clarifying an unknown issue of carbon relationships with soils. I’ve taken a few pictures of the article and highlighted some outstanding information. The technical words “sink” means a place where the carbon is absorbed, whereas “source” means carbon release. “Organic carbon” is carbon mostly combined in molecules with the elements hydrogen, oxygen, and nitrogen; CO2 is not considered organic carbon.

See how the process of erosion exchanges carbon with the atmosphere. No natural process is steady/firm; everything is subject to changes, cycles of changes, chemical equilibriums in which roles can actively change.

I’ve personally never heard any conversation of “global warming by CO2” about carbon cycles with soils. I actually learned from this info. I have no minimum idea on how the “climate change models” that predict catastrophes, destructions and extinctions accommodate natural process that we still do not have quite clear, let alone totally unknown.

This is another proof that the climate change “science” is indeed junk science. The climate change conversations that you hear from the government and TV newscasts are not a comprehensive understanding of how it all really works, don’t get fooled by what they say; they are not experts, they are not consulting experts, and those who fill the “consensus of agreements” are nothing but opinionated individuals with no research/solid data to show, with funds to push forward false ideas.

That has been proven by honest scientists and engineers.

JBVigo, PhD

Reply to  Dr. Jimmy Vigo
February 19, 2023 11:10 pm

The climate change conversations that you hear from the government and TV newscasts…

Wrong. There is no conversation from them, only amongst them.
They are morally prohibited from having an actual conversation with unbelievers…

Reply to  cilo
February 20, 2023 1:16 am

Leftists do not debate
That prevents debate losses.
They character attack to make opponent seem unworthy of debate.
Leftists are horrible people who should be neutered.

Reply to  Richard Greene
February 20, 2023 3:46 am

…and there you go, playing right into Bolshie’s hand. By threatening violence, you have now not only given grist for Their ‘Independent Judiciary’, you have implicated all of us who do not immediately reprimand you, preferably erase you from (virtual) existence.
So, naughty boy, go sit in the corner!…!!! I have to dissociate, but I’m too lazy shocked and traumatised to move over myself.

Reply to  Dr. Jimmy Vigo
February 20, 2023 1:13 am

Nice piece of info! I shared this in my blog site, the pictures I took from the text are omitted here.

You sound like you know what you arer talking about.
How about a link to your blog?
I can’t find it with Google

Reply to  Richard Greene
February 20, 2023 3:47 am

it’s always nice , when webmasters link your name to your page, or supply some link next to your handle…

Jim Gorman
Reply to  Dr. Jimmy Vigo
February 20, 2023 5:15 am

You have very succinctly expressed my reservations. As a EE trained in thermodynamics of steam operated electric plants and very well trained in the electromagnetic wave concepts I continually am disappointed how “averages” continue to be the lingua franca of climate science. I was impressed when I read “across time and space using decay functions“, as the implication of gradients is a term seldom seen in climate science.

Too much of climate science is dealing with temperature vs time and trying to show how CO2 and temperature are correlated. Nothing causal will ever be proved by continuing to show correlations. Time is not a part of a functional relationship between CO2 or temperature. Time can only be used in describing gradient values of related variables. A causal relationship will have one as the independent and the other as the dependent variable. When was the last time you saw one of those?

February 20, 2023 3:35 am

Background …

Contour bunding or contour farming or Contour ploughing is the farming practice of plowing and/or planting across a slope following its elevation contour lines. These contour lines create a water break which reduces the formation of rills and gullies during times of heavy precipitation, allowing more time for the water to settle into the soil.[1] In contour plowing, the ruts made by the plow run perpendicular rather than parallel to the slopes, generally furrows that curve around the land and are level. This method is also known for preventing tillage erosion.[2] Tillage erosion is the soil movement and erosion by tilling a given plot of land.[3] A similar practice is contour bunding where stones are placed around the contours of slopes. Contour ploughing helps to reduce soil erosion.

In agriculturecover crops are plants that are planted to cover the soil rather than for the purpose of being harvested. Cover crops manage soil erosionsoil fertility, soil quality, water, weedspests, diseases, biodiversity and wildlife in an agroecosystem—an ecological system managed and shaped by humans. Cover crops may be an off-season crop planted after harvesting the cash crop. Cover crops are nurse crops in that they increase the survival of the main crop being harvested, and are often grown over winter.[1][2] In the United States, cover cropping may cost as much as $35 per acre.

No-till farming (also known as zero tillage or direct drilling) is an agricultural technique for growing crops or pasture without disturbing the soil through tillage. No-till farming decreases the amount of soil erosion tillage causes in certain soils, especially in sandy and dry soils on sloping terrain. Other possible benefits include an increase in the amount of water that infiltrates into the soil, soil retention of organic matter, and nutrient cycling. These methods may increase the amount and variety of life in and on the soil. While conventional no-tillage systems use herbicides to control weeds, organic systems use a combination of strategies, such as planting cover crops as mulch to suppress weeds.[1]

The US farmers that I know understand the value of their soil and work hard to retain it … and have for decades.

Doug Huffman
February 20, 2023 3:51 am

All of these news aggregators need to lead their ledes with the source. If I see the AXIOS or QUORA or Quillette (feminized dimunitive of ‘quill’ pen) I skip ahead. Not worth the time.

Thank goodness for WUWT.

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