Soil compaction, remediation and mulching, the rhizosphere

[Tony Croft aka hamadryad]

Compost Tea, Soil Microbiology, and Sustainable Agriculture

[Tony Croft aka hamadryad]

MMMM... compost teas, maybe not the all singing all dancing?

 

http://www.puyallup.wsu.edu/~linda%20chalker-scott/horticultural%20myths_files/Myths/Compost%20tea%20again.pdf

 

I have a home landscape with many trees, shrubs, and groundcovers. I don't use pesticides except for an

occasional shot of Roundup; I don't use fertilizers, unless I can determine a deficiency (most commonly

nitrogen, which I add as fish meal only to plants that need it); I don't add anything else to the landscape

except wood chips as an organic mulch. I don't have disease problems, I don't have insect pests, I have a

healthy, organic landscape. This tells me that compost tea is not crucial for landscape health. If a

landscape has serious soil or plant health problems, it is not likely that compost tea is going to solve the

problem. Often in urban areas the problems are soil compaction, overuse of fertilizers (especially

phosphate), overuse of pesticides (especially fungicides which harm soil health), etc. Poor plant quality,

improper plant siting and installation, and lack of proper aftercare also increase plant health problems.

Adding compost tea will not solve these problems.

The Bottom Line

• Composted mulch has been documented to suppress disease through a variety of methods

• Non-aerated compost teas may be useful in suppressing some pathogens on some plants

• Aerated compost teas have no scientifically documented effect as pathogen suppressors

• Overuse and runoff of compost teas could conceivably contribute to water pollution

• There is no “silver bullet” for plant health problems caused by poor soil health and improper plant

selection and management

For more information, please visit Dr. Chalker-Scott’s web page at http://www.theinformedgardener.com.

 

and another on compost teas http://www.woodsend.org/pdf-files/compost_tea.pdf

Edited June 25, 2010 by Tony Croft aka hamadryad

[Tony Croft aka hamadryad]

Well for me I think nothing has changed in my personal view of compost teas, they have a use, to be applied WITH a mulch for preference, to assist and boost the soil flora and balance out the whole equation of bio remediation of the Rhizosphere.

 

As far as mulch is concerned I have always believed that most claims are for too thin a layer, and this has to be proved to me by someone, maybe marcus can help me understand why this is the case?

 

For me and in my personal experience on my own plants and trees a deeper layer has always proved the most benificial, too thin a layer does not retain a damp environment within the upper layers where most aerobic activity takes place. It is the action of worms that take the mulch into the deeper layers, and the deeper it goes the less rapid is its breakdown, adding to the moisture retention within deep layers and aeration increases as worm poulations rise aggragation increases and humus content biulds.

 

in my experience i have had no negative effects using mulch upto 6inches deep, depth of mulch is the biggest factor in weed suppresion, one of the main benifits froma maintanence point of view.

[Tony Croft aka hamadryad]

Geography and Geology — Soil Investigation and Data Management Tools

[Will Hinchliffe]

When applying soil additives or tackling soil compaction I feel it is necessary to have some idea of the impact the change to the soil will have. Consideration of the site history must be undertaken.

 

Habitat destruction is as great a threat to fungi as it is to other organisms in the UK. When adding nutrients to the soil by mulching or adding fertilizers we change the soil environment and the species make up of the microbial communities change.

 

Ancient woodlands have escaped the ploughing, manuring and applications of imported and artificial fertilisers that surrounding farmland has been subjected to. The soils of some woodlands may host fungal communities that have evolved and adapted over thousands of years. Some woodlands have very low nutrient levels and it is thought that even the small increase in the levels of atmospheric Nitrogen due to the advanced technology we now use is influencing the woodland mycota. Nitrophillic Fungi become more prevalent occupying niches previously taken by fungi that are adapted to low nutrient environments. So imagine how drastic an effect applying mulch could have to an ancient woodland soil.

 

Also think of the miccorhizae in a soil. The genetics of the fungi involved vary with provenance. We need to conserve this variation. Changes to there habitat may lead to them being out competed and lost from a site. In my opinion one of the worst things horticulturists and arborists are doing at the moment is adding spores of miccorhizae forming fungi to soils where fungi are already present. There seems to be no research investigating the influence these inoculations have on the soil fungi that are present. I would suggest that as the species chosen for these inoculations are chosen because they so readily form associations they may have a good chance at out competing fungi that is presents especially if you pulverise all the hyphae by use of an air spade.

 

Airspades, Terravent machines, mulches and miccorhizal inoculations all have there uses in managing trees and the landscape. There use in woodlands and on undisturbed soils should really be very carefully considered. More research is defiantly required.

[Tony Croft aka hamadryad]

Phenom, I really do appreciate all your saying, and i do also recognise the shortcomings of Mycorrhizae inoculi, I wouldnt use them myself.

 

as for mulching a basic soil analysis around the vets im thinking of would reveal only the pressence of Patho fungi due to high compaction, high urea and little organic if any content, also soil errosion from lack of vegatation and foot traffic, rain wind errosion of the top layer.

 

in THESE cases a mulch is the ONLY line of action to bring in defensive organisims.

[Lee Winger]

MMMM... compost teas, maybe not the all singing all dancing?

]

 

Trust me, compost tea DOES work, and it works very well indeed, last year I planted 6 rows of sweet corn, 3 rows were occasionally drenched in a compost tea the other 3 not, the difference was staggering...

 

This year I am trialling compost tea as a pest fighter broad beans and black fly, so far a noticeable difference.............

 

Its whats in the brew that makes all the difference, but as you say teas need the full nine yards to work super efficiently, mulch, oxygen, water .................

Edited June 28, 2010 by Lee Winger

[Lee Winger]

When applying soil additives or tackling soil compaction I feel it is necessary to have some idea of the impact the change to the soil will have. Consideration of the site history must be undertaken.

 

Habitat destruction is as great a threat to fungi as it is to other organisms in the UK. When adding nutrients to the soil by mulching or adding fertilizers we change the soil environment and the species make up of the microbial communities change.

 

Ancient woodlands have escaped the ploughing, manuring and applications of imported and artificial fertilisers that surrounding farmland has been subjected to. The soils of some woodlands may host fungal communities that have evolved and adapted over thousands of years. Some woodlands have very low nutrient levels and it is thought that even the small increase in the levels of atmospheric Nitrogen due to the advanced technology we now use is influencing the woodland mycota. Nitrophillic Fungi become more prevalent occupying niches previously taken by fungi that are adapted to low nutrient environments. So imagine how drastic an effect applying mulch could have to an ancient woodland soil.

 

Also think of the miccorhizae in a soil. The genetics of the fungi involved vary with provenance. We need to conserve this variation. Changes to there habitat may lead to them being out competed and lost from a site. In my opinion one of the worst things horticulturists and arborists are doing at the moment is adding spores of miccorhizae forming fungi to soils where fungi are already present. There seems to be no research investigating the influence these inoculations have on the soil fungi that are present. I would suggest that as the species chosen for these inoculations are chosen because they so readily form associations they may have a good chance at out competing fungi that is presents especially if you pulverise all the hyphae by use of an air spade.

 

Airspades, Terravent machines, mulches and miccorhizal inoculations all have there uses in managing trees and the landscape. There use in woodlands and on undisturbed soils should really be very carefully considered. More research is defiantly required.

 

And the big difference is we a dealing in general with urban trees, messing about with a low traffic woodland ecology is beyond the scope of us mere mortals...

[Lee Winger]

Trust me, compost tea DOES work, and it works very well indeed, last year I planted 6 rows of sweet corn, 3 rows were occasionally drenched in a compost tea the other 3 not, the difference was staggering...

 

This year I am trialling compost tea as a pest fighter broad beans and black fly, so far a noticeable difference.............

 

Its whats in the brew that makes all the difference, but as you say teas need the full nine yards to work super efficiently, mulch, oxygen, water .................

 

Nearly forgot, it works on trees too, or should I say has an effect................

[Tony Croft aka hamadryad]

When we talk about low traffic woodlands what are we calling low traffic?

 

A vet in hatfiel;d forest is a magnet, those in the front of house positions must have a million feet plus stamping all over them, this is only going to increase as more and more people begin to appreciate veteran and ancient trees.

 

these Old growth trees are under as much if not more pressure than those in any urban setting