Knotweed and other Invasive Species Reports/Removal

[Gary Prentice]

21 minutes ago, Nimrod Environmental said:

If that's the case Gary then I apologise. I must have misunderstood.

No worries, the embarrassed emoji was to indicate my embarrassment after commenting on what, I previously thought, were largely worthless guarantees. 

 

I apologise for the sarcasm in my response

[openspaceman]

On 12/5/2017 at 10:15, richy_B said:

The 25 year guarantee isn't necessarily that it won't regrow. It is that the client will not icur financial cost / is indemnified by your and your underwriter for that period.

I treat a lot of JK and I find after 2 years with no regrowth you are unlikely to see if re-emerge. Unlikely not impossible though. I've seen patches come 'back to life' after 10 years when it's been disturbed.

resurrecting an old post but this:

https://link.springer.com/article/10.1007%2Fs10530-018-1684-5

 

appears to confirm that the rhizome is seldom killed just put into some sort of dormancy by glyphosate

[Yournamehere]

Thanks for that osm.

BBC did tldr just yesty.

Nice to have some details.

[Khriss]

I think its down more to good monitoring of a site- rather than what ticket or guarantee you offer - as with OPM,  its down to long term management security of a site . K

[Wonky]

My tuppence worth, a long time ago, I remember seeing somthing on tv,  some company had a mobile incinerator, I forget what temp it had to get the soil.. but every bit of soil went through it at a rate that would insure every bit of knott weed was ash when it came out.

 

and yes it was costly, but it ment that nothing was removed from site

 

 

edited to add google search,

put this in google

mobile incinerator to burn knotweed

Many things come up, this being one

https://addfield.com/addfield-fight-knotweed/

 

you will see it’s also used for rhododendrons   By

http://www.kingwell-holdings.co.uk/invasive-species/

 

Edited April 26, 2018 by Wonky
Add google search

[Nimrod Environmental]

1 hour ago, Wonky said:

My tuppence worth, a long time ago, I remember seeing somthing on tv,  some company had a mobile incinerator, I forget what temp it had to get the soil.. but every bit of soil went through it at a rate that would insure every bit of knott weed was ash when it came out.

 

and yes it was costly, but it ment that nothing was removed from site

 

 

edited to add google search,

put this in google

mobile incinerator to burn knotweed

Many things come up, this being one

https://addfield.com/addfield-fight-knotweed/

 

you will see it’s also used for rhododendrons   By

http://www.kingwell-holdings.co.uk/invasive-species/

 

Hi Wonky,

 

I've looked into these before but I think they are just to incinerate the above ground growth. With Japanese Knotweed this is not the most viable part of the plant its the underground rhizome which is the real problem. I'm yet to see something which you can dump soil straight into and it comes out JK free.

What we've done before is sift the rhizome out of the soil and then incinerate the rhizome on its own which works, however you cant guarantee that you got every bit of rhizome out during the sifting process so it still needs a warranty and monitoring for a number of years.

 

There's also the environmental effect on the soil to consider if all the soil is incinerated. Every bit of good bacteria and insect will also be killed so the soil would be useless for anything other than fill.

[openspaceman]

47 minutes ago, Nimrod Environmental said:

Hi Wonky,

 

I've looked into these before but I think they are just to incinerate the above ground growth. With Japanese Knotweed this is not the most viable part of the plant its the underground rhizome which is the real problem. I'm yet to see something which you can dump soil straight into and it comes out JK free.

What we've done before is sift the rhizome out of the soil and then incinerate the rhizome on its own which works, however you cant guarantee that you got every bit of rhizome out during the sifting process so it still needs a warranty and monitoring for a number of years.

 

There's also the environmental effect on the soil to consider if all the soil is incinerated. Every bit of good bacteria and insect will also be killed so the soil would be useless for anything other than fill.

I agree with all you have said; the thing is it is not necessary to incinerate (turn to ash) but just to sterilise it and this need only be 90C (in fact for composting waste it only needs to  reach 70C for one hour). Doing this retains all the Soil Organic Matter  but will of course kill all the other beneficial microbes.

 

At my last job we had a contract to eradicate JKW from a prestigious development so I advocated  soil sterilisation and did some figures on it but the main contractor opted for reburying the contaminated soil in plastic wrapped cells 4 metres down and my boss preferred to constant income stream from repeated foliar spraying of anything they missed.

 

From the quoted paper it looks like overdosing with glyphosate had a negative effect and correct but weaker doses translocated better to the rhizomes in autumn. This is much what my late friend and vegetation management expert told me, high doses traumatise the tissue so it does not transport the chemical as well. Even when it translocates to the rhizome it only disrupts meristematic tissue that is active in the rhizome, dormant "buds" can remain viable. Also there was not significant lateral translocation.

 

With damp soil having a density of about 2000kg/m^3 and a specific heat of 1.48kJ/kg per degree C it's an expensive business to sterilise it, I calculate about £2/m^3 in fuel alone,  but there are ways round it if some heat is recycled.