Value of wood chips as soil conditioner/fertiliser

[Scribus]

Does the cost of chipping branch trimmings outweigh the benefits of spreading them on fields? All we were told at college was that they take far too long to rot and tie up N in the soil while doing so. But that was in the era when the fashion was to throw Nitram at everything in sight.

 

[Macsky]

Does the cost of chipping branch trimmings outweigh the benefits of spreading them on fields? All we were told at college was that they take far too long to rot and tie up N in the soil while doing so. But that was in the era when the fashion was to throw Nitram at everything in sight.

Newman Turner reckoned it only locked up N when it was turned into the soil, spread on the surface it would be fine, plus a thin layer of chips won’t take long to decompose exposed to air on the surface so any N that is used in the process is only lost temporarily, but the fungal and bacterial benefits could last much longer.

 

[Kiwi Pete]

It shouldn't.
Unfortunately when you get into the "lets throw nitrogen at the crops" then it tends to create a very bacterial (read: weedy, hungry) soil biome, and by adding slower forms of carbon then we're effectively bringing the balance back (more fungal, healthy, resilient soils)
The fault of modern cultivars is that they are bred for high nitrogen, high input sysyems - this may not be compatible with future farming, although many will disagree. It certainly isn't the soils problem, it's man's.

So, it really depends on you, your system and mindset as to what you believe is worth bringing in and what isn't - the only thing I buy in is woodchip. Certainly no nitrogen, that's legume's part of the deal.
Hence we are on the upward spiral, whereas the dung spreaders and fertiliser spreaders are reaching their profitability plateau, because C and N are intrinsically related - adding N uses C. Adding C doesn't reduce N, it requires the rhizobia to provide more N, which they rapidly do.

 

[Macsky]

Thinking about it, I wonder if anyone has looked into the incorporation of woodchips in NVZs to reduce N leaching?

 

[Clive]

Does the cost of chipping branch trimmings outweigh the benefits of spreading them on fields? All we were told at college was that they take far too long to rot and tie up N in the soil while doing so. But that was in the era when the fashion was to throw Nitram at everything in sight.

compost it first then apply to soil, mixed with muck etc its VERY valuable

Burning or removing ANY carbon from you fam that isn't being paid for is a very silly thing to do as a farmer

 

[Scribus]

It shouldn't.
Unfortunately when you get into the "lets throw nitrogen at the crops" then it tends to create a very bacterial (read: weedy, hungry) soil biome, and by adding slower forms of carbon then we're effectively bringing the balance back (more fungal, healthy, resilient soils)
The fault of modern cultivars is that they are bred for high nitrogen, high input sysyems - this may not be compatible with future farming, although many will disagree. It certainly isn't the soils problem, it's man's.

So, it really depends on you, your system and mindset as to what you believe is worth bringing in and what isn't - the only thing I buy in is woodchip. Certainly no nitrogen, that's legume's part of the deal.
Hence we are on the upward spiral, whereas the dung spreaders and fertiliser spreaders are reaching their profitability plateau, because C and N are intrinsically related - adding N uses C. Adding C doesn't reduce N, it requires the rhizobia to provide more N, which they rapidly do.

The major change to the mindset required there is the consideration of the balance of what's in the soil rather than just the total amounts. Fungal/bacteria and C/N ratios are features of soil science that, from memory, were never mentioned! However, that was a long time ago when organic farmers were considered weirdos and generally laughed out of the room. It's good to some science being applied to non chemical farming.

Do you have an application strategy for woodchip, the frequency and spreading rate?

 

[Scribus]

compost it first then apply to soil, mixed with muck etc its VERY valuable

Burning or removing ANY carbon from you fam that isn't being paid for is a very silly thing to do as a farmer

Wouldn't the problem there be that you are double handling the material and so adding to the cost? Is it possible to apply a monetary value at all?

 

[egbert]

compost it first then apply to soil, mixed with muck etc its VERY valuable

Burning or removing ANY carbon from you fam that isn't being paid for is a very silly thing to do as a farmer

hmmmm....I hear what you're saying, but when you've got 500mm- 1000mm of carbon sitting between the grass and the mineral rich subsoil, the value of the carbon is more tenuous. Carbon credits for leaving it sat there one day I suppose

 

[Scribus]

hmmmm....I hear what you're saying, but when you've got 500mm- 1000mm of carbon sitting between the grass and the mineral rich subsoil, the value of the carbon is more tenuous. Carbon credits for leaving it sat there one day I suppose

FYM would surely be bringing minerals to that carbon layer, woodchips will as well, though to a lesser extent.

 

[Scribus]

Newman Turner reckoned it only locked up N when it was turned into the soil, spread on the surface it would be fine, plus a thin layer of chips won’t take long to decompose exposed to air on the surface so any N that is used in the process is only lost temporarily, but the fungal and bacterial benefits could last much longer.

After a quick browse of the interwebby thing it appears that one possible mechanism for decomposition on the surface is through fungi which harbour nitrogen fixing bacteria. When the material is buried this process is disrupted and degeneration of the cellulose/lignin is is left to soil bacteria which rely on N in the soil for metabolism, thus making the soil nitrogen hungry.

 

[Macsky]

After a quick browse of the interwebby thing it appears that one possible mechanism for decomposition on the surface is through fungi which harbour nitrogen fixing bacteria. When the material is buried this process is disrupted and degeneration of the cellulose/lignin is is left to soil bacteria which rely on N in the soil for metabolism, thus making the soil nitrogen hungry.

We have a lot to learn.......or maybe relearn!

 

[phil the cat]

Does the cost of chipping branch trimmings outweigh the benefits of spreading them on fields? All we were told at college was that they take far too long to rot and tie up N in the soil while doing so. But that was in the era when the fashion was to throw Nitram at everything in sight.

I’m all for muck and spreading but have just cleared some grassland with overgrown hedges and we logged the thick stuff and burnt the rest- it’s just the cost and time associated with chipping the brash that put us off. Considered using it for cattle bedding but the high moisture content and thorns put us off that too

 

[Scribus]

I’m all for muck and spreading but have just cleared some grassland with overgrown hedges and we logged the thick stuff and burnt the rest- it’s just the cost and time associated with chipping the brash that put us off. Considered using it for cattle bedding but the high moisture content and thorns put us off that too

And there's the rub, it's quantifying the value of spreading the chippings that is the difficult part.

 

[Clive]

Wouldn't the problem there be that you are double handling the material and so adding to the cost? Is it possible to apply a monetary value at all?

I do t see it as a problem - carbon is what we all sell, don’t give it away

 

[Scribus]

I do t see it as a problem - carbon is what we all sell, don’t give it away

True, but then again we mustn't sell it at below cost price.

 

[Clive]

I’m all for muck and spreading but have just cleared some grassland with overgrown hedges and we logged the thick stuff and burnt the rest- it’s just the cost and time associated with chipping the brash that put us off. Considered using it for cattle bedding but the high moisture content and thorns put us off that too

Pile it up and it will compost eventually, in the mean time it will provide home for insect and bird life etc many of which are beneficial to your farm

Mix some FYM with it and it will compost faster

I see no logic whatsoever for burning carbon, it’s not great for the environment or our bottom line

 

[Kiwi Pete]

The major change to the mindset required there is the consideration of the balance of what's in the soil rather than just the total amounts. Fungal/bacteria and C/N ratios are features of soil science that, from memory, were never mentioned! However, that was a long time ago when organic farmers were considered weirdos and generally laughed out of the room. It's good to some science being applied to non chemical farming.

Do you have an application strategy for woodchip, the frequency and spreading rate?

Not really much of a plan - other than I've enough composted manure/woodchip to blanket the property at around 2T/ac.
Plenty of areas won't get any/much and the slopes will get far more.

I kinda see my ranch as an "infield composting operation" to a degree, the finer points don't worry me as much as improving the soil as quickly as possible, and making money
There's likely already an equal amount of pasture returned to the soil (via trampling) and again the idea is to tie up soil N to encourage more fixation, estimates of what clovers can fix vary wildly and perhaps this explains the range?

The lion hunts better on an empty stomach...

 

[Scribus]

Not really much of a plan - other than I've enough composted manure/woodchip to blanket the property at around 2T/ac.
Plenty of areas won't get any/much and the slopes will get far more.

I kinda see my ranch as an "infield composting operation" to a degree, the finer points don't worry me as much as improving the soil as quickly as possible, and making money
There's likely already an equal amount of pasture returned to the soil (via trampling) and again the idea is to tie up soil N to encourage more fixation, estimates of what clovers can fix vary wildly and perhaps this explains the range?

The lion hunts better on an empty stomach...

On the point of N fixation I spent some time today browsing the subject of soil fungi and I am starting to think that they might have a far greater role in soil function than I had certainly believed, and that includes the colonisation of legume roots with the appropriate bacteria.

Here's one paper that appears to show that it is the combination of fungi and bacteria that is important in legume growth -

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5221347/

 

[cows r us]

Mix it with some material that is high in n. Grass clipping or fym. Compost it properly ( keep air and moisture in the heap but don't let it get over 70c). Leave it to do its thing for a year or even two then spread it. Will be some great stuff.

 

[Barleycorn]

I get regular woodchip deliveries from a tree surgeon firm. Used to put it in a big heap and turn it with the telehandler, but now have made a windrow and turn it with the turner. As said, it will take a year to compost, unless you have a good N source to put with it.