- Location
- Owaka, New Zealand
-
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"Improving Our Lot" - Planned Holistic Grazing, for starters..
- Thread starter Kiwi Pete
- Start date
- Location
- Derbyshire UK
would the brittleness concept be relevant to determine grassland management practices in environments at the lower end of the brittleness scale i.e. UK (currently -1 underwater!)?
What does the 'brittleness' of an ecosystem mean?
The 'brittleness' of an ecosystem, in the management sense, is a statement regarding it's capacity to support biological decay of dead plant material. The term 'brittleness' comes from the simple snap test where a stem of a plant is bent. If it snaps, it's dry and if it bends, it's moist. If humidity is high enough, dead vegetation will retain enough moisture to support biological decay. If humidity is too low, the dead vegetation will not decay, it will oxidize, a chemical process.
A 'brittle' environment is one in which humidity is very low and/or seasonally sporadic. The more 'brittle' the environment, the greater the number of days per year in which dead vegetation is dry. It is not a matter of total precipitation per year, but the distribution of humidity throughout the year.
The brittleness scale is not an objective scale, but a subjective judgement based on observation. In a 'wet' year, east-central Alberta would probably rate in the 4-5 range, but in a drought year, it would probably rate a 7-8. In general, it could be referred to as a 'semi-brittle' region but managing grasslands in this region will require adjustment based on year-on-year variation in rainfall.
Most of the world's grasslands ecosystems fit in the 'semi-brittle' to 'brittle' end of the scale.
Why does 'brittleness' matter?
Brittleness matters for a simple reason, it determines the mechanism(s) required to produce biological decay and prevent oxidative/chemical decay of dead vegetation. In order to support healthy soil, dead plant matter must break down biologically and the nutrients liberated from the old material be added to the soil. In addition, dead plant material that is left standing will prevent sunlight penetrating to the new leaves of young plants. With insufficient sunlight, this new growth is hampered in much the same way that a wood chip mulch will help prevent weed growth in a flowerbed. If left to decay chemically, grasslands lose biodiversity and biomass over time, causing the soil to develop a hard surface (poor water infiltration) and slowly open patches of soil open up where the plant life has died off. Exposed to sunlight, it overheats, killing remaining biology. Exposed to rain/wind, it begins to erode.
Therefore, in a semi-brittle or brittle environment, another mechanism is needed to force biological decay of plant material. In nature, this is provided by animal impact. Vast herds of bison, wildebeest, zebra, etc, eat and trample old vegetation. This trampled vegetation and dung is deposited in a shallow mat on the soil surface, protecting it from wind, rain and sun. This layer of soil is called the detritusphere. Because it is protected from wind and sun, humidity from the soil is trapped below and inside this mat. This creates a safe and hospitable living space for a multitude of insects, worms and other organisms that get to work breaking down the dead plant material and recycling it into the soil. In addition, this mat of decaying material, combined with the action of soil biology hard at work, create a spongy porous topsoil able to rapidly infiltrate precipitation, where it becomes available for use by plants and soil biology.
Above the detritusphere, the new plants now have only to put up shoots a short distance to find full sun. With unimpeded access to sunlight above the mat of dead vegetation, new plants can rapidly get on with photosynthesis and restarting the whole cycle.
It was the discovery of the vital importance of animal impact to semi-brittle and brittle grasslands ecosystems that lead to regenerative rangeland management systems.
I chain harrow grassland in the spring to remove "dead thatch" allowing sunlight into the grass sward to maximise photosynthesis and warm the soil encouraging grass growth (and make the moles angry!). Or am I just destroying a beneficial "Detritusphere"?
- Location
- Glen Clova, Angus, DD8 4RD
Here some 15 acres in the middle of the farm belong to neighbours but we graze it. They don't want the 6 acres they can see from their house "looking untidy" so that constraint prevents us adopting long covers just there. They have the right to determine that.@bitwrx
This is the exact dilemma I find myself in and a really am struggling to find a way forward. Annoyingly, it is me who is the 'older' generation and am constantly being put down for my 'way out' ideas about how HPG can really work. Even the landlord has joined in now insisting that all thistles must be sprayed next yearand that a number of fences be taken down so he may gallop his horses
It's a case of working out what you CAN do.
Could you agree with him where he will gallop and manage that accordingly?
texas pete
Member
- Location
- East Mids
The only thing I have used chain harrows for in the last 20 years is for spun on grass or turnip seed. There may be situations where it is beneficial, but I’ve never gone looking for them.
I have done too much topping in the past, but that’s another subject.
- Location
- Owaka, New Zealand
I'd love to still have litter in the spring, TBH
The soil here eats more than I could give it last year, anyway.
The soil here eats more than I could give it last year, anyway.
Yes, it's more 'squidgy' rather than brittle round here atm.
I dont do all that grass harrowing and subsoiling stuff, as paying the deisal bill gets harder.
Well actually weve not got those implements either , nor a topper
- Location
- Derbys/Bucks.
TBH managing the paddocks and fencing so that the LL can still ride out isn't too much of an issue. Good strategic steel wire and a fair bit of temporary fencing will do the job. However its dealing with the longer grass and perceived weeds (diverse leys) and countering the conventional 'graze to the ground and tidy up with the topper and sprayer' mindset that is the big one to overcome.
- Location
- Devon
Ref the idea of removing dead thatch. Where do we expect it to go if harrowing it out? It's got to go into the soil at some point surely? So I figure harrowing it out counter productive.
I use to do that a lot of years ago now I get keep sheep on it in nov/dec they shove it in the ground this saves diesel and get paid for it
- Location
- Glen Clova, Angus, DD8 4RD
Am understanding that brittleness influences how different management practices actually affect the environment is key. In our non-brittle uk climate (here we are a 4 or 5) we can get away with things that would be seriously damaging in a 7 or 8 environment.
I understand why you chain harrow but why not trample it in instead:
. Less fuel use
. Less time input
. Less risk of compaction
. Feed the soil biology
- Location
- Derbyshire UK
Makes a lot of sense, but what about shallow compaction with all that trampling?
- Location
- Devon
I'm coming to the conclusion that compaction isn't an issue from trampling provided they're kept moving.
The damage is from animals tramping around the same piece of ground for weeks.
- Location
- Glen Clova, Angus, DD8 4RD
Also MUCH less of a risk once you get more organic matter into the top 4 inches of soil (it becomes open and "bouncy" preventing the hooves causing compaction).
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And that is exactly why a layer of litter is so important here. (Among other reasons too)
What does the 'brittleness' of an ecosystem mean?
The 'brittleness' of an ecosystem, in the management sense, is a statement regarding it's capacity to support biological decay of dead plant material. The term 'brittleness' comes from the simple snap test where a stem of a plant is bent. If it snaps, it's dry and if it bends, it's moist. If humidity is high enough, dead vegetation will retain enough moisture to support biological decay. If humidity is too low, the dead vegetation will not decay, it will oxidize, a chemical process.
A 'brittle' environment is one in which humidity is very low and/or seasonally sporadic. The more 'brittle' the environment, the greater the number of days per year in which dead vegetation is dry. It is not a matter of total precipitation per year, but the distribution of humidity throughout the year.
The brittleness scale is not an objective scale, but a subjective judgement based on observation. In a 'wet' year, east-central Alberta would probably rate in the 4-5 range, but in a drought year, it would probably rate a 7-8. In general, it could be referred to as a 'semi-brittle' region but managing grasslands in this region will require adjustment based on year-on-year variation in rainfall.
Most of the world's grasslands ecosystems fit in the 'semi-brittle' to 'brittle' end of the scale.
Why does 'brittleness' matter?
Brittleness matters for a simple reason, it determines the mechanism(s) required to produce biological decay and prevent oxidative/chemical decay of dead vegetation. In order to support healthy soil, dead plant matter must break down biologically and the nutrients liberated from the old material be added to the soil. In addition, dead plant material that is left standing will prevent sunlight penetrating to the new leaves of young plants. With insufficient sunlight, this new growth is hampered in much the same way that a wood chip mulch will help prevent weed growth in a flowerbed. If left to decay chemically, grasslands lose biodiversity and biomass over time, causing the soil to develop a hard surface (poor water infiltration) and slowly open patches of soil open up where the plant life has died off. Exposed to sunlight, it overheats, killing remaining biology. Exposed to rain/wind, it begins to erode.
Therefore, in a semi-brittle or brittle environment, another mechanism is needed to force biological decay of plant material. In nature, this is provided by animal impact. Vast herds of bison, wildebeest, zebra, etc, eat and trample old vegetation. This trampled vegetation and dung is deposited in a shallow mat on the soil surface, protecting it from wind, rain and sun. This layer of soil is called the detritusphere. Because it is protected from wind and sun, humidity from the soil is trapped below and inside this mat. This creates a safe and hospitable living space for a multitude of insects, worms and other organisms that get to work breaking down the dead plant material and recycling it into the soil. In addition, this mat of decaying material, combined with the action of soil biology hard at work, create a spongy porous topsoil able to rapidly infiltrate precipitation, where it becomes available for use by plants and soil biology.
Above the detritusphere, the new plants now have only to put up shoots a short distance to find full sun. With unimpeded access to sunlight above the mat of dead vegetation, new plants can rapidly get on with photosynthesis and restarting the whole cycle.
It was the discovery of the vital importance of animal impact to semi-brittle and brittle grasslands ecosystems that lead to regenerative rangeland management systems.
Also nice shout out to East Central Alberta
Exposure of the top layer of soil always puts it at risk of damage. Exposure to heat, cold, wind, rain... that layer of detritusphere protects but also absorbs water. Go rake up a handful, dry it out, then stick it in a bowl with a couple cups of water, see how much it absorbs.
Think of it as the corn starch thickening your soup. It’s going to help your land from becoming too watery by acting as a thickening agent.
And since it protects the top layer of soil from hardening you’re more likely to achieve better “deep” water absorption instead of just surface run off and pooling.
Also, in a wet environment that residue is going to break down much faster than in more brittle areas. Your litter layer may be gone completely in a matter of months or maybe even weeks, here it could take years. By harrowing it away you’re actually removing the exact stuff you want to be there to build up OM.
You don’t have to trample it much to get it down enough for new growth to poke through. Also in your environment a lot of your trample is still going to be actively growing most of the year so will bounce back up and carry on its way instead of having to start from ground level beneath the thatch.
- Location
- Quebec, Canada
You could spray the thistles with molasses and see what happens@bitwrx
This is the exact dilemma I find myself in and a really am struggling to find a way forward. Annoyingly, it is me who is the 'older' generation and am constantly being put down for my 'way out' ideas about how HPG can really work. Even the landlord has joined in now insisting that all thistles must be sprayed next year
- Location
- Cornwall
Got some weeds in your ryegrass Pete?![emoji57]
looks like docks to me
got to love em
- Location
- Owaka, New Zealand
There's a heap of species in there if you look closely enough. A heap everywhere TBH, I took note of some of the things @Blaithin was discussing a while (seems like a lifetime!) ago re recording species in a small hoop at random, and I can usually see upwards of 20 species present.
So my "diverse mix" is actually less diverse than the rest of the ranch by this time of year.
Lots of things you probably wouldn't drill in, but it's all alive and kicking!
So my "diverse mix" is actually less diverse than the rest of the ranch by this time of year.
Lots of things you probably wouldn't drill in, but it's all alive and kicking!