Most cost effective way to build soil carbon

[The Ruminant]

Mikep, I completely agree that any form of continuous cropping will deplete soil OM - unless (and this where we disagree) a lot of FYM is applied to the soil. My father had a smallholding that was permanently cropped, but we also had prodigious quantities of FYM from pigs and poultry. I do not have the records now (I think I lost them in Australia) but the soil OM was high through yearly heavy applications of FYM. FYM is OM. It may not be in a form available to the plants, but it is OM, and any picked up in soil samples will be included in the %age of OM in the results. It will in time become available to the plants. If you say otherwise, then what do you consider to be OM?

My experience is not limited to this farm, or even this country, hence my request for research to show that what I have experienced does not always follow.

From your last line, I think we are agreeing on the best way of increasing OM. My whole point in posting originally was to suggest to IEM that he might read Elliott's book and perhaps be persuaded to follow the idea of a 4 years' ley followed by 4 years' cropping. On a mixed farm, that is my preferred system. I only have two small fields that are not in olives or almonds, so cannot use the system here.

The only record I have seen of someone following Elliott for a long time is a book by William Lamin "Thirty Years farming on the Clifton Park system". Well worth reading, as well as Elliott, and is also available online.

Thank you for referencing Lamin's book. I've read Elliot and Turner but hadn't come across Lamin's......until now! Already downloaded and on my iPhone ready to read at leisure

 

[Old McDonald]

I am still working on my understanding on of soils. I get a bit confused by statements like OM being used up by crops.
My understanding is that soil is made up of minerals, water, air and anything carbon based is organic matter. OM is anything from undecayed crop residue to an earth worm and everything in between. The ways I see "carbon" getting into the soil are from 1)decaying plant residue and roots, 2) root exudates that the plant produces to "feed" soil microbes for its benefit 3) from what farmers add. There is a soil food web using this OM as the primary food source, some of the carbon is "burnt" off as carbon dixoide by the microbial activity. But more complex forms and stable forms are produced and nutrients are released for plants to use by this. There was a great digram I saw at an Elaine Igrams talk of bacteria having more nitrogen than protozoa so that when protozoa ate bacteria they excreted the excess nitrogen which plants ( or bacteria ) could use.
I see humus as the end product of the soil food web, but I don't really understand what is.
Are soils with high OM healthy because of the soil microbes they support or due to the nutrients being released from the OM. If soils have limited soil microbes, for example a lot of intensive farmed soils are meant to be bacterial dominated so do they just burn off the carbon from the OM without alot of other benefits.
Although biochar adds carbon to soil and i think it is meant to be a good home for soil microbes, I don't see it as complex carbon source that can be food for microbes so is it really OM.
My understanding could be wrong and I would happy for where I have gone wrong to be pointed out.

That is an excellent post.

Do not worry that you do not understand it all - neither does anyone else. One of the biggest problems is in the description of various parts of the process from living to dead vegetation; other organic material that ends up on the surface of the land (all of it except for human intervention); organic material within the soil that has not yet decomposed; decomposed organic material in the soil, and finally, humus.

Nobody understands humus. I sometimes quote myself because it is so much simpler for me than trying to type something new, and here goes another:

In simple terms OM in the soil is the total (usual expressed as a % figure) of living and dead micro-organisms plus partially decayed animal and vegetable matter. Humus is a chemically complex residue of decayed vegetable matter in the soil according to the Royal Horticultural Society of England. This ignores animal matter. Some authorities will tell you that humus is a dark brown or black colloidal mass of only partially decomposed OM in the soil, and many writers use the latter definition. If it is in its partially decomposed form, I believe it is best to still refer to it as OM, otherwise you then have the problem of finding an alternative definition for OM, and that would cause even more confusion than already exists. There are even those who refer to all organic material added to the soil as humus, which of course it is not, and the description of it being “the top layer of soil containing freshly broken down OM” is also wrong. I prefer the opinion of Jack Hadfield author of The A-Z of Vegetable Gardening in South Africa a book that has been published and republished many times from 1967 into the 21st Century. He wrote “Humus is perhaps best described as a product of the decomposition of plant and animal matter through the agency of micro-organisms.” This is close to the RHS definition with the inclusion of animal sources. He goes on to say that “the regular addition of potential humus to the soil is the very foundation of fertility.” A most profound statement that to ignore would almost certainly result in the collapse of any soil. Humus, using Hadfield’s definition, has a Carbon to Nitrogen ratio of 10:1 or very close to it, and this fact should be remembered because it is of the utmost importance.

Animal droppings and urine, FYM and composted animal with vegetable material are all considered to be a source of OM for the soil and are usually referred to as organic manures, or simply manure or muck, whilst 100% vegetable matter, or something that is mainly vegetable matter and a little animal manure, then composted is usually known as compost. Crops grown with the specific intent of incorporating them into the soil are called green manures.

You will find that some people, particular those authors from around the 1930s to 1950s will refer to a combination of FYM and other vegetation that has been rotted down in pits or heaps as compost too rather than FYM, even if the added vegetable material is a lesser proportion than that derived from the animals and their bedding. I take the other view that FYM has historically been accepted as animal dung and urine mixed with their bedding, which obviously is of vegetable origin, and the addition of other products, e.g. vegetable waste, paper, leaves and twigs, is a smaller part of the whole, so it remains FYM, whether fresh from the animal housing, or stockpiled and rotted down.

...............................................................................

OM is not a constant. It is a variable percentage of the total ground beneath our feet which we refer to as soil. The amount in any soil varies. As I said, it seems nobody really understands the transference from raw animal and vegetable matter to humus, but it basically appears a general consensus that the raw material undergoes a transformation via the "underground workforce" that makes the nutrients within the OM available to plants as food.

Please do not use the modern expression burnt in relation to what happens to carbon.

You use the expression "healthy" in relation to soils. What is unhealthy? If a soil is not sterile, meaning it can grow crops, then it is "healthy". Whether or not is is productive is another matter.

 

[mikep]

I am still working on my understanding on of soils. I get a bit confused by statements like OM being used up by crops.
My understanding is that soil is made up of minerals, water, air and anything carbon based is organic matter. OM is anything from undecayed crop residue to an earth worm and everything in between. The ways I see "carbon" getting into the soil are from 1)decaying plant residue and roots, 2) root exudates that the plant produces to "feed" soil microbes for its benefit 3) from what farmers add. There is a soil food web using this OM as the primary food source, some of the carbon is "burnt" off as carbon dixoide by the microbial activity. But more complex forms and stable forms are produced and nutrients are released for plants to use by this. There was a great digram I saw at an Elaine Igrams talk of bacteria having more nitrogen than protozoa so that when protozoa ate bacteria they excreted the excess nitrogen which plants ( or bacteria ) could use.
I see humus as the end product of the soil food web, but I don't really understand what is.
Are soils with high OM healthy because of the soil microbes they support or due to the nutrients being released from the OM. If soils have limited soil microbes, for example a lot of intensive farmed soils are meant to be bacterial dominated so do they just burn off the carbon from the OM without alot of other benefits.
Although biochar adds carbon to soil and i think it is meant to be a good home for soil microbes, I don't see it as complex carbon source that can be food for microbes so is it really OM.
My understanding could be wrong and I would happy for where I have gone wrong to be pointed out.

Carbon can be both inorganic or organic. Biochemistry is the study of the chemistry of carbon the only element to have its own branch of science. This is the reason it is so complex. The phrase burnt is used to describe the rapid degradation when cultivations expose the o m to plentiful oxygen.
The whole importance and relationship of soil chemistry/biology is only now really being taken seriously by 'mainstream' agriculture and will probably be chewed over for many many years.
There will be no 'correct answer' as all soils vary (but this wont stop people claiming to have it all sussed) just general guidlines so if what you are doing seems to work then keep on doing it.

 

[The Ruminant]

Please do not use the modern expression burnt in relation to what happens to carbon.

You've mentioned on a couple of occasions your dislike of the "modern" term 'burnt'. I am not so sure it's that bad - after all, respiration, combustion, decomposition etc all take a complex carbon molecule and use oxygen to split the carbon molecule, releasing energy in the process.

There's also the argument that the English language is fluid and, if something is popular, it should become OK to use it, (much like the word "ok" is, well, OK these days whereas when I was growing up it was forbidden, especially in the written form!) "Decimate" is another example which, in its original meaning, indicates reducing by ten; nowadays it means to virtually obliterate.

Anyway, I'm going way off-thread and must start work - just to finish by saying I understand what is meant by "burning off carbon" and I'm sure most other people do too!

PS You keep referring to your "writings" - where do we find them in their entirety as I thoroughly enjoy and agree with much of what you say on here (so much so that I can ignore the antiquated style of prose you use )

 

[conor t]

Mikep, I completely agree that any form of continuous cropping will deplete soil OM - unless (and this where we disagree) a lot of FYM is applied to the soil. My father had a smallholding that was permanently cropped, but we also had prodigious quantities of FYM from pigs and poultry. I do not have the records now (I think I lost them in Australia) but the soil OM was high through yearly heavy applications of FYM. FYM is OM. It may not be in a form available to the plants, but it is OM, and any picked up in soil samples will be included in the %age of OM in the results. It will in time become available to the plants. If you say otherwise, then what do you consider to be OM?

My experience is not limited to this farm, or even this country, hence my request for research to show that what I have experienced does not always follow.

From your last line, I think we are agreeing on the best way of increasing OM. My whole point in posting originally was to suggest to IEM that he might read Elliott's book and perhaps be persuaded to follow the idea of a 4 years' ley followed by 4 years' cropping. On a mixed farm, that is my preferred system. I only have two small fields that are not in olives or almonds, so cannot use the system here.

The only record I have seen of someone following Elliott for a long time is a book by William Lamin "Thirty Years farming on the Clifton Park system". Well worth reading, as well as Elliott, and is also available online.

Maybe you saw an increase in om levels with fym because of some sort of priming effect on the beneficial soil life. Ive seen long term research showing slurry, residue and even direct drilling to have no effect on om levels so my view is that it has to be mediated through soil life which should increase longer term om turnover due to more aggregation and other forms of protection.

 

[mikep]

Maybe you saw an increase in om levels with fym because of some sort of priming effect on the beneficial soil life. Ive seen research showing slurry, residue and even direct drilling to have no effect on om levels so my view is that it has to be mediated through soil life which should increase longer term om turnover due to more aggregation and other forms of protection.

The way o m is measured is a shotgun approach as it is total amount that is burnt off in an oven irrespective of it is active or passive. You plough in a straw crop and of course total o m rises but is it useful? It can cause localised problems and tie up nutrients. I like to think there is active and inactive o m and this is where the recycler's come in to integrste it properly into the soil.
Worms are part of it as are all the other bugs that are present in a healthy soil. They break it down into forms plants can use and plants then distribute it through the soil profile by their roots this is why I like deep roots.

 

[conor t]

The way o m is measured is a shotgun approach as it is total amount that is burnt off in an oven irrespective of it is active or passive. You plough in a straw crop and of course total o m rises but is it useful? It can cause localised problems and tie up nutrients. I like to think there is active and inactive o m and this is where the recycler's come in to integrste it properly into the soil.
Worms are part of it as are all the other bugs that are present in a healthy soil. They break it down into forms plants can use and plants then distribute it through the soil profile by their roots this is why I like deep roots.

Do you mean active as in live+decomposing biomass and inactive as om locked up in an aggregate/adsorbed onto clay where it cant be accessed?
There is a test that gives an indication of these that uses potassium permanganate, very quick and easy but dont know if a lab would do it.

 

[mikep]

Do you mean active as in live+decomposing biomass and inactive as om locked up in an aggregate/adsorbed onto clay where it cant be accessed?
There is a test that gives an indication of these that uses potassium permanganate, very quick and easy but dont know if a lab would do it.

I really cant define it but i like to think there is food stock i.e. manure straw etc and o m that has been incorprated into the system by the soil fauna and also o m that has been 'fixed' by plant roots.
The food stock is not an indicator of soil health as you can add muck to totally devastated soils and they will not immediately spring to life so to me that leaves the incorporated or active o m and if you can measure that it would be a better indication of soil health.
Its very simplistic but it seems the right way to me.

 

[Old McDonald]

PS You keep referring to your "writings" - where do we find them in their entirety as I thoroughly enjoy and agree with much of what you say on here (so much so that I can ignore the antiquated style of prose you use )

I write in an antiquated style because I am antiquated, but not quite so much that I would have started looking by clicking on the webpage below every post. I do not "do" funny little symbols - because I am antiquated.

 

[Old McDonald]

You've mentioned on a couple of occasions your dislike of the "modern" term 'burnt'. I am not so sure it's that bad - after all, respiration, combustion, decomposition etc all take a complex carbon molecule and use oxygen to split the carbon molecule, releasing energy in the process.

Again, being antiquated, the word burnt means something has been combusted and destroyed - unless you have a new modern meaning for it.

 

[The Ruminant]

I write in an antiquated style because I am antiquated, but not quite so much that I would have started looking by clicking on the webpage below every post. I do not "do" funny little symbols - because I am antiquated.

Emojis (for that is what they are called) are actually quite useful to convey the tenor of one's message. A simple smiley face avoids people interpreting an intended joke as a serious comment, for example, thus avoiding offence. I was a sceptic to start with but can see how they make the written word a little more like the spoken word

 

[The Ruminant]

Also, @Oldmacdonald where can I buy / acquire some of your elusive writing?

 

[The Ruminant]

Again, being antiquated, the word burnt means something has been combusted and destroyed - unless you have a new modern meaning for it.

 

[Old McDonald]

Maybe you saw an increase in om levels with fym because of some sort of priming effect on the beneficial soil life. Ive seen long term research showing slurry, residue and even direct drilling to have no effect on om levels so my view is that it has to be mediated through soil life which should increase longer term om turnover due to more aggregation and other forms of protection.

I struggle to follow exactly what you have posted, but, since FYM is OM it has to increase the OM in the soil when it is applied to the land. How speedily that OM becomes available to plants or is used up depends on many factors, but if the soil is in a very depleted state in respect of the size of the "underground army" then that army simply does not have the ability to break down the applied FYM (or any other applied OM) until it is able to increase its numbers. Consequently there will be a delay in the applied OM providing nturients to whatever is growing on the land.

My experience is in four different countries on vastly different properties, but the effects have been repeatable. As I asked mikep, if you can lead me to some research which shows different results to those which I have experienced I would truly like to read the reports. If my experience is an anomaly I want to know that it is, and why. I will then happily try to some other system. Elliott could be wrong, but I have not yet seen anything which suggests he is. If the information is out there I want to read it.

 

[Old McDonald]

Also, @Oldmacdonald where can I buy / acquire some of your elusive writing?

I presume you have by now read my post #69. If not, then click on the link to my wepage and read away at your leisure.

 

[The Ruminant]

I presume you have by now read my post #69. If not, then click on the link to my wepage and read away at your leisure.

I'm reading it on an iPhone and can't see any links, signatures etc. Apologies if it was obvious to those on a normal computer - I'm not really crazy, honestly!

I'll now have to get my laptop..... or you could just type the link, specially for me

 

[Old McDonald]

Since you ask so nicely and appear not to be crazy................ www.oldmcdonaldsolives.com

 

[Old McDonald]

Emojis (for that is what they are called) are actually quite useful to convey the tenor of one's message. A simple smiley face avoids people interpreting an intended joke as a serious comment, for example, thus avoiding offence. I was a sceptic to start with but can see how they make the written word a little more like the spoken word

I take your point, but I find that people use these little pictures indiscriminately and they do not always match the words which have been written. As an example, what is your thumbs up sign supposed to indicate? That you like what you have written? That you think it is a good idea? That I should think it is a good idea?

I can see that if you had not posted it, but that I did, then it would mean that I thought it was a good idea. As it stands, I regret you have not convinced me to move into the 21st Century. My son has been cajoling me for many years that I should move into the 20th. Would a smiley face be appropriate here? If not, what would?

Aside from that, I think you might enjoy Sir Albert Howard's "An Agricultural Testament" (probably available from the same place as Lamin's book) since it includes details of how he made "Indore Compost". It sounds like a good source of nutrients, but like most organic sources it means depleting someone else's land to enrich your own.

 

[N.Yorks.]

Add material that once lived to the soil, it then starts to be broken down by living organisms such as fungi, bacteria, actinomycetes, algae, protozoa and larger organisms like earthworms down to nematodes. In a cubic meter of topsoil it is estimated there are around 7 trillion individual organisms. I mention just this one figure to put into context the enormity of the living mass within the soil, and I am sure that the actual figure in any given area of soil will be highly variable. Put this another way, in a grassland soil the approx. weight of bacteria is in the range of 1-2 t/ha and fungi 2-5 t/ha.

In your minds visualise two groups of soil matter: the first used to be alive, the second is still alive.

The matter that used to be alive (crop residues, FYM, compost, destroyed cover crops, dead microbes etc) will not just remain they will be 'dismantled' from their whole into smaller fractions i.e. they are broken down by the living matter within the soil. Basically it's a massive food chain
.
Plant matter/ crop residues can be split into:

• rapidly decomposed: sugars, starches, proteins
• less rapidly decomposed: cellulose, hemicellulose
• slowly decomposed: waxes, resins, lignin

Some of these crop residues can be broken down quickly by a relatively few number of organisms and others will be broken down gradually by a diverse range of organisms. I'll avoid attempting a detailed description of which organisms do what, as we'd probably be here all night and I'd probably not get it totally correct either.

Basically it's a massive food chain.

The value of all this to farmers are huge.
The breakdown by-products will partly be plant nutrients that can be used by growing crops to satisfy their nutritional requirements. This is why FYM use provides N, P, K, Mg, Ca. The type of matter that is being broken down will determine how quickly these plant nutrients can be re-cycled.
There are also a number of compounds excreted by the organisms that are responsible for maintaining soil structure which in turn is critical to maintaining pores within the soil through which water can drain and air can diffuse.

If you take away the organic matter from the soil these beneficial characteristics start to reduce.

By now hopefully you envisage the soil as having a number of inter related mechanisms, a bit like an engine and gear box. If you stop the supply of fuel into an engine you know what happens. If you stop/restrict the feeding of once living matter (OM) then that restricts the ability of the complex array of living organisms to exist and that in turn restricts the benefits that we need in order to maintain soil fertility and crop production.

Another dimension to appreciate is that the array of organisms present in the soil will be larger when more diverse types of organic matter are available. So a soil that just gets a stubble ploughed back every year will have a narrower range of living organisms than a soil that gets stubble, FYM/compost, cover crops etc. The current thinking is that a soil that has a greater diversity of organisms will be more likely to recover from a system shock such as prolonged water logging or a drought or perhaps even a change in cultivation policy.

Basically, there isn't one cost effective way that should be favoured, you'll get more resilient soils that are able to maintain long term function if you 'treat them' to as wide a range of once living material.

And finally the humus is a "chemical junkyard" as it is the accumulation of resistant plant material and microbial waste products. Humus is stable and very slowly broken down.

It's all about re-cycling.......... be it FYM, dead roots already in the soil or compost!

I've tried to condense what could easily be written down on hundreds of pages into a few paragraphs, I hope you get the gist.

 

[Farmersdaughter]

Add material that once lived to the soil, it then starts to be broken down by living organisms such as fungi, bacteria, actinomycetes, algae, protozoa and larger organisms like earthworms down to nematodes. In a cubic meter of topsoil it is estimated there are around 7 trillion individual organisms. I mention just this one figure to put into context the enormity of the living mass within the soil, and I am sure that the actual figure in any given area of soil will be highly variable. Put this another way, in a grassland soil the approx. weight of bacteria is in the range of 1-2 t/ha and fungi 2-5 t/ha.

In your minds visualise two groups of soil matter: the first used to be alive, the second is still alive.

The matter that used to be alive (crop residues, FYM, compost, destroyed cover crops, dead microbes etc) will not just remain they will be 'dismantled' from their whole into smaller fractions i.e. they are broken down by the living matter within the soil. Basically it's a massive food chain
.
Plant matter/ crop residues can be split into:

• rapidly decomposed: sugars, starches, proteins
• less rapidly decomposed: cellulose, hemicellulose
• slowly decomposed: waxes, resins, lignin

Some of these crop residues can be broken down quickly by a relatively few number of organisms and others will be broken down gradually by a diverse range of organisms. I'll avoid attempting a detailed description of which organisms do what, as we'd probably be here all night and I'd probably not get it totally correct either.

Basically it's a massive food chain.

The value of all this to farmers are huge.
The breakdown by-products will partly be plant nutrients that can be used by growing crops to satisfy their nutritional requirements. This is why FYM use provides N, P, K, Mg, Ca. The type of matter that is being broken down will determine how quickly these plant nutrients can be re-cycled.
There are also a number of compounds excreted by the organisms that are responsible for maintaining soil structure which in turn is critical to maintaining pores within the soil through which water can drain and air can diffuse.

If you take away the organic matter from the soil these beneficial characteristics start to reduce.

By now hopefully you envisage the soil as having a number of inter related mechanisms, a bit like an engine and gear box. If you stop the supply of fuel into an engine you know what happens. If you stop/restrict the feeding of once living matter (OM) then that restricts the ability of the complex array of living organisms to exist and that in turn restricts the benefits that we need in order to maintain soil fertility and crop production.

Another dimension to appreciate is that the array of organisms present in the soil will be larger when more diverse types of organic matter are available. So a soil that just gets a stubble ploughed back every year will have a narrower range of living organisms than a soil that gets stubble, FYM/compost, cover crops etc. The current thinking is that a soil that has a greater diversity of organisms will be more likely to recover from a system shock such as prolonged water logging or a drought or perhaps even a change in cultivation policy.

Basically, there isn't one cost effective way that should be favoured, you'll get more resilient soils that are able to maintain long term function if you 'treat them' to as wide a range of once living material.

And finally the humus is a "chemical junkyard" as it is the accumulation of resistant plant material and microbial waste products. Humus is stable and very slowly broken down.

It's all about re-cycling.......... be it FYM, dead roots already in the soil or compost!

I've tried to condense what could easily be written down on hundreds of pages into a few paragraphs, I hope you get the gist.

Really like and agree with this post, but to add to it. Think plants can also feed the microbes excreting about 50% of the sugars they make to feed them. Not sure if they are the same population as those that break down the OM though. The other thing is I am not sure the humus is the junk, maybe it is more like the larder, a food store of complex stable molecules that can broken down when fresh food runs out.