Sugar water for trees, good or bad? Soil | Carbon | Plant Sugars | Roots

Ekka

We all know trees make sugars via photosynthesis.

So, a theory evolved that watering trees with sweet water is a benefit.

Some studies have showed the opposite.

http://www.madsci.org/posts/archives...9620.Bt.r.html

http://www.jennifermarohasy.com/blog...es/000830.html

Problem is the trees cant absorb the sugar, but does sugar improve soil and mychorizae?

If we can get some facts down I'll be able to clean the thread up for inclusion into Tree Fact Factory.

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Sean Freeman

Sugar and the soil food web, very interesting stuff.

Here's a press release from CSU;

and yes here's a PDF with more detail about the study and some photos;

sweetendtoweeds.pdf

I have reservations when claims are made for any single soil amendment as the answer to problems faced by trees. However the proven role sugars play in the rhizosphere is critical to the health of the bottom trophic level, the micororganisms, bacteria and fungi. The exudation zone around the roots of plants has higher sugar concentrations than the surrounding soil structure, that is extremely attractive to the microorganisms who need those sugars to be able to complete their own metabolic processes...in this way these sugars (simple carbohydrates) are essential to arguably the most important cycle going on (from the plant's perspective) the process of ionisation within the soil profile.

You can find more than enough data at the USDA, Natural Resources Conservation Service website http://soils.usda.gov/sqi/concepts/s...y/biology.html
There are nine chapters plus lots of links, references etc...

However for those who are less patient here's a paper by Dr Elaine Ingham (from around 1995) that explains the soil food web very well, as Arborists pay particular attention to the explaination of how in the process of predation Nitrogen is accumulated in the soil (around the roots);

The Soil Foodweb ecosys health.doc

Some of our understanding of interrelationships between soil microorganisms has advanced since this paper was written but the general tenents are still valid.

Now having gained (hopefully) much knowledge from that paper, visit this site from the USDA Ag research service and draw on the specfic understanding of the relationship between mycorrhizal fungi and plant roots re sugars;

http://www.ars.usda.gov/is/AR/archiv.../fungi0501.htm

I'm not sure this is enough to get it moved into the Tree Fact Factory, but I'll be honest and say for me the relationship is well proven and although I started out as a skeptic; re the impact of simple sugars on tree health, I have become a true believer,
I don't feed trees, only the sun can do that, but I sure as hell feed the soil trees live in.

__________________
Sean

Trees are poems that earth writes upon the sky,
We fell them down and turn them into paper,
That we may record our emptiness.
- Kahlil Gibran

Roller

I was told that if you water with sugar solution ,it must be sugar without sulphate

Sean Freeman

Roller the most important factor in determining what soil amendments we use has to be the results we get from comprehensive soil tests at the outset.

I'm not advocating the use of sugar in all and every situation to improve soil biota, there has to be thorough examination and diagnosis of what if anything is lacking in the particular soil profile being looked at, and this is of course in conjunction with an understanding of the interplay between plant (tree) and the soil food web.

It can get very confusing discussing this across continents since we all work with different soil classification systems, very different climates, different plants and very different soils.

Sugar in the form of pure molasses, when applied as a diluted soil drench does have a well understood impact on the organisms living in the upper horizons, but you must first know what organisms are there and how they are interacting before you can even consider influencing any aspect of the rhizosphere.
Basic soil structure and chemistry is still a huge factor in the health of not only the plants living there but also all the other living organisms.

__________________
Sean

Trees are poems that earth writes upon the sky,
We fell them down and turn them into paper,
That we may record our emptiness.
- Kahlil Gibran

Sean Freeman

I know this is a bit odd dragging an old thread up from the past but the question of sugar soltutions came up on UKTC in relation to dealing with damage to tree roots by footpath construction..........sooooooooooo.......here from the ensuing debate are some excellent bits of research.....some of which some of you will have already read...think of it as revision

joa2005sugar.pdf

sugar feeding and root vigour.pdf

One lump or two.doc

__________________
Sean

Trees are poems that earth writes upon the sky,
We fell them down and turn them into paper,
That we may record our emptiness.
- Kahlil Gibran

Treelore

Without getting too embroiled in the subject. Sugar, Mollasses, Carbohydrate drenches, etc are a bacterial stimulant. Great for grasses and lower plant species but not real good for trees as they are fungally dominant. We have already in our landscapes bacterially dominant circumstances due to extensive grassed systems and unhealthy soils which prohibit the proliferation of fungal biomass.

Therrin

So we can spread granulated sugar over the ground before we throw down mulch, and it'll help to more quickly promote mycorrhizal growth beneath the mulch?



Or does it not work that way?

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Ken Fessia
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Ekka

Doesn't work that way, also this explains why not to mulch with grass clippings (primarily bacterial not fungal)

Soil Foodweb Inc. about us

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Sean Freeman

Now I don't want to put anyone off by disappearing into jargon so I'll keep this as straight forward as I can..

The point of this particular thread was to examine and discuss the relative usefulness of applying sugar (simple carbohydrate) solutions to the soil and root environment of trees in terms of boosting the health and vigour of those trees.

Why sugar?....trees cannot take up sugar molecules from the soil..so whats the point???

Well to understand the importances of simple sugars in the soil and root environment you need to start looking at the soil in a slightly different way, instead of seeing and concieving of it as "dirt" you need to see it as a living web of interrelated organisms...many very very small (bacteria) and some very familiar and large (worms, beetles etc). All these organisms interact with each other compete for physical space and resources...they make up what is called the soil food web. Lets put to one side for a moment the unnatural state of our urban soils and look at the model...



Now Treelore is correct that it is possible when examining what is going on in the soil food web for a particular vegetative community...prairie grass lands for example...to identify a dominance of certain elements of the web in relation to others, he points out that grass lands tend to have a greater ratio of bacteria to fungi...ie bacteria dominate the microscopic levels in the web, what is termed the first trophic level. Because the bacteria dominate this first (bottom if you like) level in the web it has a cascading effect throughout the web and the physical and chemical characteristics of the soil generally......the soil environment (soil food web) that evolves under a grass dominated community is (in theory) far from ideal for normal healthy tree growth. (I'll return to this later...please bear with me!!!!)

But what has this to do with sugar!!!!!

The simple carbohydrates that sugar represents, be it sucrose, glucose or fructose are essential to the life cycle of both bacteria and fungi....indeed the payoff for those mycorrhizae is that the tree delivers carbohydrate direct to the fungi, the theory/model if you like is simple; when mycorrhizae are present in a relatively healthy soil the introduction of simple sugars....sugar water.....will produce accelerated fungal growth, increasing the chances of root inoculation.

Simple sugars are also stimulants for bacteria...yes, but not exclusively, one of the problems I and others have with some minor aspects of the way the soil food web model is applied is precisely this kind of confusion.

Vegetative communities that are dominated by grasses do support very long lived healthy tree growth...not closed canopy forests, no, not old growth forest, but open Eucalyptus and Melaleuaca forests are very significant to the evolution of our continent.

The oldest trees in the UK and some parts of Northern Europe are found in woodland pasture, not in old growth closed canopy forest...and yes I know that is a reflection of the human agricultural influences on the land and the vegetation but nevertheless these veterans are there, and where human impacts are minimal (no road or house building etc) they are living out their life cycle relatively unaffected by the presence of large volumes of grass species as an understorey.

Nobody is suggesting that merely by applying sugar solutions alone structural problems in the ecosystem of the soil can be redressed..that is not the case.
Sugar solutions or sugar water if you like should be part of a comprehensive program of plant health care...that begins with establishing what is going on (or not going on) in the soil and around the roots of the tree in question, thensets about trying to redress some of the problems that we can affect...some we cannot as arborists working on a single site have any immediate impact on eg disappearing ground water!

Carbon loss is often the single most important aspect of the soil ecosystem that requires attention...applying mulch in the form of aged wood chips and forest mulch ideally from the same mix of species that make up the ecosystem being worked on...... The purpose of the mulch the carbon source is to provide fuel for the soil food web, sugar water and compost teas (brewed deliberately to replace identified short falls in the exisiting food web) are the stimulants to kick start the process of decomposition that is critical to all the cycling going on in the soil.

Sugar solutions as part of a wider program of soil works are very good for trees indeed....and it is a mistake to think that fungi are not predisposed to breakdown sugars when they are available in the soil...that is precisely what they do and thank the gods they do too...the so called "sugar fungi" (together with bacteria) immediately absorb the simple sugars and amino acids and the explosion in the population of "sugar" decomposers is critical to the functioning of the next trophic level in the soil food web...ass the simple compounds are used up these "sugar" fungi decline, but their excretory products and they themselves become part of the mineralisation process in teh soil and lead into the decomposition of more complex organic compounds.

I know its getting complicated to follow......

What I'm trying to say is that the many very critical fungi species (critical to the health of trees) are stimulated directly and indirectly by the addition of simple sugars to the soil and root environment...yes bacteria are stimulated too and that is a good thing.

Models are essential to our understanding very complicated sets of relationships...3D relationships at that! However models sometimes give us a falsely simplified view of those relationships......

The rhizosphere is a tiny and emmense environment all at the same time, it is constantly in flux. the micro biology of the rhizoshere around the roots of an ancient oak in open pasture in a field in Scotland is different to that found 20 metres away in the soil around the hawthorn hedgerow.

Its even more interesting (and complex) in areas like the Mitchell grass lands of Western Queensland...where my love Michelle lives (AKA the explorers tree Hughenden)...but maybe for another thread eh?

(hope I didn't put you all to sleep )

__________________
Sean

Trees are poems that earth writes upon the sky,
We fell them down and turn them into paper,
That we may record our emptiness.
- Kahlil Gibran

Treelore

It's late and I have a couple of beers under my belt so if this is nonsense I'll re-explain tomorrow. For the most part I agree with Sean. However either due to his lack of explanation much the same as I was trying to avoid I may have misinterpreted some of what he said.
Fat people who live on pizza and macdonalds are alive. Moreso they can remain alive for extended periods of time. Their health and combative abilities however do remain in question due to their susceptibility through inadequacies within their diet.
There is no question that higher plant species require a higher fungal component to their ratios than bacterial....Does this suggest that bacterial quantities or responses are not necessary for higher plant growth??? Of course not... So as Sean mentioned holistic plant care is of a greater benefit. If you spray sugar water over a trees root system you will feed Bacteria in turn feeding protozoa and definitely increasing total biomass for the tree. This will increase readily available nitrogen because of C/N ratios between bacteria and protozoa but do nothing more than promote growth as Seans studies mentioned.
Trees exude into their soil something in the vicinity of 85% of their created sugars to feed surrounding organisms to benefit their lifestyle. Ordinarily throughout the millions of years that they have been adapting, sugar was the lacking component!! Without human disturbance fungal foods have always been in abundance. Cellulose, lignin and carbon are the food substances for fungus. Previously in history they were always present. With extensive land clearing and sunbaked earth these fungi have been seriously depleted because their condition is a moist and warm environment and they no longer exist. It is now our job to recognise original bacterial/fungal ratios as with protozoan and nematodal numbers and attempt to re-introduce that into our existing soils!!

Treelore

This is the most serious thread on here!!!!! It means more than ropes and equipment and noones posting!!!!! guys learn something it is more important than where your cuts are or what chipper you have, get involved and get your understanding on trees in order!!!

Ekka

I'm cutting a wad of them down tomorrow, I'll let them know.

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Sean Freeman

Eric is that spoon getting heavy yet??


Just a quick post as i finalise my packing for the fortnightly slog to the southeast corner.....Its late-ish and my weekend has been fragmented to say the least.

Treelore is quite correct when he says that there are more important things than cutting into the canopy with a chainsaw....a great many of us myself included have spent a great deal of time perfecting what we do to the above ground parts of trees..how much to cut, where to cut when to cut what to spray so on and so on....We have only really ever looked at the roots when it comes to deciding if the tree is unstable due to root loss or dysfunction, very very few of us have developed a good understanding of just what the heck is going on in the soil, between the plant and the myriad of other living organisms.

This topic sugar water for trees good or bad, really by its title misses the real issue about what is happening in the rhizosphere...the micro universes between the plant (trees) and the soil food web (and that includes the physical and chemical struture and processes in the soil).

What I have tried to point towards is the usefulness of sugar solutions as part of much bigger and comprehensive program of soil works aimed at reinvigourating that universe down below.....I am not suggesting that we should all go out and throw bags of sugar around (though you might want to give that a go in your vege patch)

What I am saying is that as Arborists we should have a working understanding of the soil food web and how it relates to the different vegetation communities we encounter in our regions. We should all know what the importance of fungal and bacterial ratios is, how and why it can effect tree health, longevity and vigour. We should all understand the absolutely fundemental part the living organisms in the soil play in all of teh biological cycles that at school were taught to us as if they occured devoid of any organic living elements at all.

WHY?

Because then we can actually begin to offer our clients total plant health care, we can actually approach severely declining trees and see beyond the chop and drop option that formed the basis for tree work 20/30yrs ago....there will always be a place for the removal of trees, for the formative pruning of trees for the appropriate species selection and planting of trees.....chainsaws will always be a part of tree work....no question.....But if we are to learn anything from the growing realisation of the appauling consequences of our impact on the environment around us it should be that releasing more carbon into the atmosphere is not a good idea. (When you cut down and chip up trees and leave the ground exposed to the sun and elements it is a triple negative whammy in the carbon cycle)

I may have appered to have meandered off the simple topic somewhat but bear with me I'll bring this snowball around!!!

There are many ways we can manage trees in the urban environment, in soils that have been so massively transformed by the processes of human development that they bear hardly any resemblence to anything approaching a natural form or structure.....here's just a small selection

We can plant into these soils without alteration, without soil works the toughest most resliant species we know of and watch them very slowly struggle growing shortened troubled lives to be overwhelmed after less than 25% of their potential life span by the latest blight of pest.

We can create large engineered planters into which we plant the species we want knowing that they will be limited by the contained soil and root volume provided for them...huge pot plants, to be replaced in 20..maybe 30yrs (though more likely 10yrs)

We can argue for proper planning of significant green spaces in new subdivisions that will be excluded from civils and have at least 12 months of intensive soil works applied to them prior to any long term tree plantings.

We can apply comprehensive soil works to our existing urban forest (where its future growth is a sensible proposition) based not on astrology or I ching, or any snake oil but on the detailed microscopic assay of the soil food web in each location, and base our remediation work on those results....mush of our urban forest is literally clinging to edge of a decline spiral, and though we may not yet be able to precisely determine what each species in each and every region requires we do currently have sufficient understanding and knowledge to tilt the scales in favour of longer stronger healthier tree growth.

Everyone has choices to make all the time little choices big choices, all of us, we make up the communities in which we live and work, we elect the officials to office in councils and government yet we all very often act as if it were someone elses responsibility to effect change........

There are a great many ways to manage trees in the urban environment.....I know which way makes the most sense to me, and a small part of it will occaisionally envlove sugar water

Attached Images

wizardstirringpot.jpg (6.8 KB, 79 views)

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Sean

Trees are poems that earth writes upon the sky,
We fell them down and turn them into paper,
That we may record our emptiness.
- Kahlil Gibran