Organic mater clay soils

[Yorkshire lad]

We have over the past few years stopped buying P and K using sewage cake and our own muck
We have increased organic matter in our soils from 3.5 % to 6.5% I have also noticed rhat our soils seem to be harder to work to a seedbed if we plough it seems to turn over in a slab
I have read that you can have to much organic matter in clay soils and the ideal content is 4% I find this hard to believe , I thought that you can't have to much organic matter ,but the Romans did make bricks from clay and straw
I know the last few autumns have been damp and our soil had not cracked like it does in a dry year so is it more weather conditions or is my organic matter to high

 

[Brisel]

Your sampling methods need looking at...

I'm half joking. Ignore how the Romans made bricks - I make strong concrete by putting in reinforcing rods which is about as equally relevant to this.

What are your earthworm numbers like? That's a far better indicator of soil health than some silly lab test with a poor sample.

How often are you applying organic matter? You'd have to be applying an NMax dose every year for 20 years and chop all straw and no till to get that response.