- Location
- North Bucks
dontknowanything said:
Is this one of those cases where you need a Cation displacement test to show the true percentages?
Kinsey seminar
- Thread starter Clive
- Start date
Is this one of those cases where you need a Cation displacement test to show the true percentages?
Feldspar
Member
- Location
- Essex, Cambs and Suffolk
Fran loake said:
If you get numbers like this and you haven't had one done then yes it is necessary.
I found it an interesting few days
slow to start but got better, could have done without the sales pitches though he was preaching to the converted quite often
learnt a fair bit and full of ideas now
great to meet many of you, some for the first time
slow to start but got better, could have done without the sales pitches though he was preaching to the converted quite often
learnt a fair bit and full of ideas now
great to meet many of you, some for the first time
dontknowanything
Member
- Location
- Cambridge
Fran loake said:
I am waiting for displacement results. My best result originally was 98.1% Ca, 0.9% Mg
dontknowanything
Member
- Location
- Cambridge
fred said:
I get why the Mg would increase as the Ca decreases, but I don't get why the soils are sticky even when the Mg is so low?
SilliamWhale
Member
dontknowanything said:
Flocculation or Deflocculation maybe? :?
- Location
- North Bucks
dontknowanything said:
These Mg figures could change considerably after you have a displacement test done. I was talking to Neal about our (similar) numbers and he said that there is no way of knowing what they will ultimately be until after the test. I'm going to ask for the displacement test and it will be interesting to see where we both end up. Ours are 93.45% and 3.68%
Fran
I only made the 2nd day in the end as due to unforseen circumstances I had to get back,but interesting all the same and a good turnout.
Comedy timing moment was what looked like Clive's phone? I phone Siri saying they didn't understand something during the middle of one of Neal's sections!
But well done to Tom for organising it all, would have stayed down if I didn't have to rush back as sounds like it was a good couple of nights!
Comedy timing moment was what looked like Clive's phone? I phone Siri saying they didn't understand something during the middle of one of Neal's sections!
But well done to Tom for organising it all, would have stayed down if I didn't have to rush back as sounds like it was a good couple of nights!
- Location
- Romsey, Hampshire
Well I thought it was a very well organised event, so thanks to Tom. I was worried after the first day that it was going to be all sales pitch and that we'd never get down to the detail we wanted to hear, but the second and third day were very good. As others have said, it was good to re connect with a number of people from here and some other friends including one that I didnt know was attending! I think in the end I felt it was an advantage to attend with little pre knowledge on plant nutrition and felt i was 'keeping up'! I too enjoyed the irony of the event being held at Rothamstead and you only needed to look around you at the smart complex with fancy loos to appreciate the importance of farmers having the tools to help themselves and not rely on large corporations and their support (control!) of the research agenda.
- Location
- Hertfordshire
I'm a novice but here's how I understand it.....
Your soils are ~90% Ca and 4% Mg on the standard CEC test. Thus, at first glance, the Mg appears to be very low and yet you still have sticky soils. However, a significant proportion of that Ca is not attached to the clay colloid - it is in excess and so is masking the true ratios. The cation displacement test 'strips away' the excess Ca and counts the actual number of negative 'sites' on the clay colloid. This then reveals the actual Ca:Mg ratio on the colloid rather than in the soil.
You very likely have a much different ratio of Ca:Mg hence your sticky soils. I'm sure there's a more accurate explanation - help, someone - but I believe this is a good starting point to understand what's happening. Does this help?
dontknowanything
Member
- Location
- Cambridge
no, on the standard tests some of our soils are >98% <1%! I was guessing what the displacement results would be. But probably best to wait for the real ones.
dontknowanything
Member
- Location
- Cambridge
OK, had some results back from Plumbo/NRM. Our heaviest field has come back at Ca 80.6 Mg 11. Agronomist is insistent that gypsum will sort it out, and alleviate the blackgrass problem amongst other things.
Thoughts?
Thoughts?
Steevo
Member
- Location
- Gloucestershire
Why add more calcium? you've already got plenty of Ca, and Mg is plenty good enough I'd have thought. I'd think you'd do better by upping your K levels.
- Location
- CW5 Cheshire
This is only my take on what Kinsey said, and I could easily have got it wrong.
The soil appears too high in Ca and Mg. The Ca must be reduced first and can only be reduced by applying excess NO3 or SO4. Once this is done, the excess Mg is exposed and can be removed by SO4, which could come from gypsum. However it would still be adding Ca back into the mix, so using NH3 SO4 fertilizer as your N source, to first reduce the Ca, and then the Mg would be my best guess.
I had an Albrecht soil analysis done a few years ago by Ground Level Nutrition, the Ca came back at 77.3% and the Mg at 5.9%. I was advised to apply gypsum to balance the Ca/Mg, but declined as I simply couldn't get my head around how it could work. I'm glad I didn't now.
Steevo
Member
- Location
- Gloucestershire
Sounds spot on Richard III. Sorry, I forgot this was a displacement result you'd have DKA. The question is.....will applying that much SO4 in excess increase your yields sufficiently to warrant the cost? I'd hazard a guess you'd be better with the the little and often approach - not trying to right the soil in 1 year, but spreading the cost over 5-10.
dontknowanything
Member
- Location
- Cambridge
We farm over chalk though, so no real way to get Ca down permanently.
- Location
- Hertfordshire
My first thought is that Kinsey stressed (and repeated the point several times) that figures from a different lab were virtually meaningless in terms of applying his knowledge. His lab (Perry Labs) would return a certain set of data that he could analyse and interpret and base recommendations on. Because of the way samples were processed, other labs would give different results and the person interpreting them would have to have knowledge of what these results mean. He wasn't saying the other labs were wrong, only that the length and handling of the treatment could lead to different figures than he gets from Perry Labs.
Either during the workshop or when we were talking privately, he said that one person he knew who wanted to continue using a different lab sent samples to both their own and Kinsey's labs for several years. He found the numbers were significantly different but, and this is the important part, were consistently different.
This allowed him to correlate the numbers so he could be confident a Ca:Mg ratio of, say 80:11 from his lab was the same as, say, 72:8 from Perry Labs.
Until you know how NRM's figures relate to Perry Labs figures, I would say it's dangerous to try to interpret them using Kinsey's recommendations