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Green Man

Organic Carbon Footprint.

On Radio 4 this morning I heard a report that the carbon footprint on organic farms is bigger than on conventional farms as the diesel used to power the cultivators that mechanically weed pump out more carbon that the production and distribution of selective weed killers.
Fee

Shocked great
Northern_Lad

Twaddle. Absolute bull-poo and if they'd listened to the people who were on Good Morning Farmers or whatever it's called that's on before the news thing they'd know that.
Yes, the footprint is bigger for fueling the transport for weeding out the weeds, but as soon as you factor in the manufacture of the chemicals the balance swings massively in favour of organic.
Nick

Hoi, stop letting facts get in the way of a headline. You know the rules.
alisjs

Northern_Lad wrote:
Twaddle. Absolute bull-poo and if they'd listened to the people who were on Good Morning Farmers or whatever it's called that's on before the news thing they'd know that.

heck, you were up early!
Glad someone's around to check news at that time in the morning (if that counts as morning!)
Green Man

Northern_Lad wrote:

Yes, the footprint is bigger for fueling the transport for weeding out the weeds, but as soon as you factor in the manufacture of the chemicals the balance swings massively in favour of organic.


It des not say that here http://www.farmersguardian.com/story.asp?sectioncode=19&storycode=14233
Behemoth

I'm confused, from the link provided:

"The manufacture and application of herbicides contributes relatively little to the carbon emissions in conventional production. Hence the additional cultivations in organic production lead to approximately double the CO2 emissions per hectare as compared with conventional weed control when comparing the functional unit as area of crop grown’, they say."

But...

"Using national average figures for conventional and organic wheat yields, organic weed control practices were responsible for three times the amount of carbon dioxide per tonne of wheat produced.

They concede that the differences would be smaller if other aspects of conventional wheat production, such as inorganic fertiliser, fungicides and pesticides were included in the calculations – 38.6kg CO2 compared to 48-58kg CO2/tonne for organic winter wheat."
Green Man

Which bit do you not understand?

Chemical weed control creates half the carbon of mechanical organic weed control per acre. (Wheat)

Chemical weed control creates a third of the carbon of mechanical organic weed control per tonne (Wheat).

The results are less extreme if you calculate the manufacture of fungicides and artificial fertiliser use and transportation, but of course a blend of the two, i.e. dung and weed killers should result in the lowest carbon footprint but this would not be acceptable to the soil association. Any farmer would far rather have natural dung over artificial, but it is very scarce.
Behemoth

Are they valid comparisons? the article says one things and then qualifies the comparison with the admission that the full chain hasn't been included.

My 17 year old volvo has the same impact as a Prius in terms of CO2 emissions.

(when measured with the engine off)

Any links to the actual study?
Green Man

Behemoth wrote:
Are they valid comparisons?


They are valid for weed control only I would imagine. Thinking about it, it makes complete sense.
oldish chris

OK, so Organic Agriculture doesn't address a problem that it was never intended to address!

The original intention was to stop poisoning the environment by giving up synthetic pesticides and to stop degrading the topsoil by no longer using chemical fertilisers.

Nothing about tractors! The other thing that gets overlooked is the use of "Barriers": plastic fleeces, netting and sheeting. (You could argue that insoluble chemicals are replacing soluble ones!)

However, the next stage in the development of organic methods are low activity techniques such as "no-dig" (or raised bed) not to mention permaculture. There are also anti-transportation initiatives going on.

George Monbiot in his book "Heat" gives tractors a special mention and dispensation from his diatribe against the internal combustion engine.
gil

One thing about organic growing of carrots specifically that annoys me is the weed control aspect.

Firstly, several passes of a mechanised flame weeder (charged out to the farmer by contractor at about £2000/acre p.a.); secondly the use of migrant labour on 'bed weeders', where the workers lie face down in a hammock-thing and weed as the machine is driven slowly across the field for 12 hours a day, six days a week through the summer. (not complaining about migrants, more that it strikes me as a pretty carp job, so probably no one else willing to do it).
Green Man

I agree with your points gil, and the article states that flame throwers are the worst type of weed control method as far as carbon is concerned.
If it is accepted that organic weed control on a commercial scale produces up to 66.6% more carbon for wheat growing per tonne, then it can be assumed that it uses a similar percentage more energy/oil to do so. So it follows that mechanical organic weed control is less sustainable long term.
gil

Depends what is powering the mechanical weeding equipment.

Flame weeders are an extreme example. They are commercially viable for growers because of the high return on organic carrots (even growing for supermarkets).

The issue with carrots is the length of time between sowing and seedling emergence, which allows weeds to overtake and smother the crop. You'll know this from growing carrots yourselves.

There are many other commercial methods of organic weed control - these mechanical, petrol-driven technologies are not the whole story. Hence you cannot conclude that the carbon footprint of organic veg is worse than of conventionally-grown.
Green Man

Again I agree, but I can only think the alternative to mechanical must be by hand, which you have highlighted needs masses of cheap labour, which in itself has environmental consequences. Which has just made me wonder, here in the fields farmers must provide portaloos for their manual workers in the field. Are organic farms allowed chemical loos? Surprised A seemingly silly, but genuine question. What would be the point of abstaining from a few litres of chemical weed control, if the organic labour creates gallons of chemical waste?
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