Soil sampling kit

croppers

Member
Location
Scottish Borders
@Brisel I'd rather you didn't as I seem to remember they were sharp and hurt and caused puncture wounds in almost anything..

The decision we have to make, or should I say, have the option to make, is to use Ca or Mg lime. I spent 12 years on the Herts Cambs border on some chalky land, over the 12 years I was there we did not spread 1 tonne of lime on the 5000+ac so the ability to influence it was nil with lime.
In Scotland where the soils are mainly naturally acidic then by this nature we have the ability where we can to influence the Ca:Mg ratio in lime applications perhaps more frequently than you (???)
Personally I like to use gypsum in the potato rotation, not to influence the pH but to bring up the Ca and S levels.
For many years the "aye been" approach to liming is flat rate Mg lime and some of the Mg levels are off the scale in our area.

Out of interest what are your average pH levels?

For me I see Calcium as the "trucker" for other elements during the growing season
 

Brisel

Member
Arable Farmer
Location
Midlands
@Brisel I'd rather you didn't as I seem to remember they were sharp and hurt and caused puncture wounds in almost anything..

The decision we have to make, or should I say, have the option to make, is to use Ca or Mg lime. I spent 12 years on the Herts Cambs border on some chalky land, over the 12 years I was there we did not spread 1 tonne of lime on the 5000+ac so the ability to influence it was nil with lime.
In Scotland where the soils are mainly naturally acidic then by this nature we have the ability where we can to influence the Ca:Mg ratio in lime applications perhaps more frequently than you (???)
Personally I like to use gypsum in the potato rotation, not to influence the pH but to bring up the Ca and S levels.
For many years the "aye been" approach to liming is flat rate Mg lime and some of the Mg levels are off the scale in our area.

Out of interest what are your average pH levels?

For me I see Calcium as the "trucker" for other elements during the growing season

That's a good point. Where my pH needs fixing the Mg index is around 1 but most of the field is around pH 8 and with lower Mg levels so I have previously chosen to boost Mg levels with kieserite, with a bit contributed by Fibrophos, sewage, compost and FYM too. I can't remember what mag lime cost last time I asked but I remember it being eye watering compared to limestone. Kieserite works out at £235/t or 94p/kg for Mg if you ignore the sulphur (for simplicity as I have NS liquid fertiliser that supplies enough S by itself).

What sort of money is mag lime these days & what dose would you apply to a pH of 5.7 so I can calculate a comparison of limestone + kieserite to mag lime? I appreciate that I'm oversimplifying 2 outcomes but I'm just trying to see how the economics work out.
 

debe

Member
Location
Wilts
Would be cheaper to use foliar mag rather than try to address your soil problems, whether it is as good? Depends how many times a week you want to go out with the sprayer.

Our behaviour on these calcareous soils could be a little better. Our fertiliser (mainly P) usage is a little irresponsible, but if we're wanting yields, it is the easiest way.

Thank you for picking up on that innuendo, I really wanted to avoid this thread but felt it was too good an opportunity to miss!
 

Mounty

Member
Arable Farmer
Location
Suffolk
That's a good point. Where my pH needs fixing the Mg index is around 1 but most of the field is around pH 8 and with lower Mg levels so I have previously chosen to boost Mg levels with kieserite, with a bit contributed by Fibrophos, sewage, compost and FYM too. I can't remember what mag lime cost last time I asked but I remember it being eye watering compared to limestone. Kieserite works out at £235/t or 94p/kg for Mg if you ignore the sulphur (for simplicity as I have NS liquid fertiliser that supplies enough S by itself).

What sort of money is mag lime these days & what dose would you apply to a pH of 5.7 so I can calculate a comparison of limestone + kieserite to mag lime? I appreciate that I'm oversimplifying 2 outcomes but I'm just trying to see how the economics work out.

There is maglime and maglime. We tend to go for the best source we can find as if you're trying to add mag you may as well get the best you can afford. Typically 21% MgO with an NV of 57-59% and around 75% through a 150micron (0.15mm) sieve. I dread to think what it would cost in Dorset @Brisel but I would hazard a guess at around £30+/tonne if that helps.
 

debe

Member
Location
Wilts
What is wrong with our P fertiliser policy? Too much of the wrong form of P applied, with a lot soon locked up?
Our indices are fine, and yet we still throw on P in an available form to boost yields. Though most will be locked up, some must be leached.

We could go on a P holiday for a few years to drag down our reserves, but we don't, we apply fresh P for that extra half ton.
 

Brisel

Member
Arable Farmer
Location
Midlands
Phosphate doesn't leach. It will run off with surface water & soil erosion but not leach much at all unless your indices are seriously high.
 

debe

Member
Location
Wilts
Phosphate doesn't leach. It will run off with surface water & soil erosion but not leach much at all unless your indices are seriously high.
All our phosphate is applied in a liquid form, solution not suspension, described as 'complex' by the manufacturer . I understand we are in the minority here. It can and does leach, just very slowly. Where we apply excess P due to the amount locked up, on highly permeable soils, some must be sneaking through.
 

debe

Member
Location
Wilts
I also wasn't so worried about the leaching, it's was more the fact that there is a finite amount of it available and hoarding it in this country is probably not the most ethical thing to do.
 

The_Swede

Member
Arable Farmer
Was talking phosphate with a chap the other day, we got onto struvite (the form chemically extracted from sewage). Currently about £1000/t by all accounts but bound to come to the fore as world reserves decrease, P price climbs and population increase continues providing ever more of the raw material!?
 

Brisel

Member
Arable Farmer
Location
Midlands
I also wasn't so worried about the leaching, it's was more the fact that there is a finite amount of it available and hoarding it in this country is probably not the most ethical thing to do.

Fudge the ethics - I have no problem going long on phosphate reserves! :D

I just need to work out how to draw down on the soil reserves now... no till, soil biology etc
 
I know I said I'm out, but Ive been somewhere field walking today which illustrates my point about finding fragments of brick and concrete all over the place.

These pics were taken in a field of OSR. Because the soil hasn't been moved for several months and the rain has washed the fragments clean, you can clearly see how much is contained in the soil. You can't see it all on the photos and there are dozens of tiny lumps to each larger lump.

IMG_0364.JPG



IMG_0363.JPG



This last photo shows how you can catch the stuff with the sampler deep down in the profile.

IMG_0361.JPG


That was in a grass flood meadow. All pics taken on the same farm today near Birmingham.

On the oilseed rape pics, this was easily the worst field of the 5 I sampled, but there were fragments in all the fields.

They don't affect the pH in the field at all. If the small bits get into a test tube they don't affect the pH result there at all. However, if they are ground in a lab test then they will affect the pH greatly, giving a misleadingly high reading.

I see fields like this most days in Warwickshire. I'm sure it's worse nearer Coventry and Birmingham where almost total destruction was seen in some parts from the Luftwaffe. I've heard on several occasions how the bomb rubble was crushed fine and spread onto fields to act as a very cheap "lime" and just to get rid of it. It may be quite rare to see, maybe just around bombed cities, but it's something I have to work around.

I'm not trying to ignite the argument on this thread, just making the point that a reliable lab result can't be obtained with samples containing this stuff.
 
I know I said I'm out, but Ive been somewhere field walking today which illustrates my point about finding fragments of brick and concrete all over the place.

These pics were taken in a field of OSR. Because the soil hasn't been moved for several months and the rain has washed the fragments clean, you can clearly see how much is contained in the soil. You can't see it all on the photos and there are dozens of tiny lumps to each larger lump.

View attachment 474740


View attachment 474742


This last photo shows how you can catch the stuff with the sampler deep down in the profile.

View attachment 474744

That was in a grass flood meadow. All pics taken on the same farm today near Birmingham.

On the oilseed rape pics, this was easily the worst field of the 5 I sampled, but there were fragments in all the fields.

They don't affect the pH in the field at all. If the small bits get into a test tube they don't affect the pH result there at all. However, if they are ground in a lab test then they will affect the pH greatly, giving a misleadingly high reading.

I see fields like this most days in Warwickshire. I'm sure it's worse nearer Coventry and Birmingham where almost total destruction was seen in some parts from the Luftwaffe. I've heard on several occasions how the bomb rubble was crushed fine and spread onto fields to act as a very cheap "lime" and just to get rid of it. It may be quite rare to see, maybe just around bombed cities, but it's something I have to work around.

I'm not trying to ignite the argument on this thread, just making the point that a reliable lab result can't be obtained with samples containing this stuff.

You've come out a few times in just this thread!
 

Mounty

Member
Arable Farmer
Location
Suffolk
On a similar theme, some pics here from last year..........
Basically, trying to show pieces of calcium carbonate (in this case chalk) within the soil that could easily be collected as part of a composite sample. In it's original state, completely unavailable to the soil. Once the chalk is crushed and put back with the soil, its clear to see how much more available it becomes.
IMG_0359.JPG IMG_0360.JPG IMG_0361.JPG IMG_0362.JPG
 

SFI - What % were you taking out of production?

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Red Tractor drops launch of green farming scheme amid anger from farmers

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As reported in Independent


quote: “Red Tractor has confirmed it is dropping plans to launch its green farming assurance standard in April“

read the TFF thread here: https://thefarmingforum.co.uk/index.php?threads/gfc-was-to-go-ahead-now-not-going-ahead.405234/
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