Posted: 07/06/2017 at 11:07
You have rumbled me! I was a "Biomedical Scientist" in a former life. I was in the backroom with all the ones in white coats who were not Doctors.
If the RHS conclusion is that the depletion is negligible then I bow to their research.
The only true example of depletion I have seen was an extreme case where someone had a large heap of woodchip on their plot. When a new tenant came & cleared it the clay underneath was Blue, another plot holder who was even more nerdy than me, did a soil test on a sample and got a negative Nitrogen reading. I accept that this is only one example and not true research and most importantly the most avid mulcher would not put that depth of woodchip down. It does show that if you want to compost it properly then you have to do what Hostafan does & layer it with other soft high nitrogen material.