Question

Are human ashes a potential fertilizer?

Answer 1

I know...weird question.

The reason I’m asking is because my history teacher said that ashes from cremated bodies in Nazi concentration camps were “dumped into a pile and later used as fertilizer for nearby cabbage fields.”

I seriously doubt this accusation. I don't think that cremated bodies would be helpful for the growth of cabbages. I think regular corpses would be better. Can anyone analyze this from a chemical standpoint?

Answer 2

I think cremation destroys almost all organic matter/ carbon based material and leaves mostly calcium, a whole slew of different metals, and possible some phosphate based compounds. I guess its possible that these phosphate compounds could be used as fertilzer. Not really sure on this though.

Answer 3

@sweetburger
You make an interesting point. I don't know much about chemistry so I appreciate you posting your thoughts.

I recently found this website:
http://www.letyourlovegrow.com/about/faq/
They sell kits where you mix soil with the ashes of your loved one so you can grow a plant.
They claim that:

"Cremated ashes contain valuable plant nutrients. However because of a very high pH level, these nutrients are locked within the ashes and not available for plant uptake. They also contain a high level of sodium (salt) that is harmful to plant life."

Thoughts?

Answer 4

There is some truth to what they say on the website, at high pH \(Ca^{2+}\) will combine with the hydroxide ion to form \(Ca(OH)_2\), a highly insoluble compound. That's what they mean by "locked within the ashes". However, I don't know that dissolving ashes from a cremation will yield a solution with a high pH in the first place.

I tried looking up some articles but haven't found anything that indicated exactly if it could be used as fertilizer... although I think it would, considering that the everything in the earth is recycled.

The statement about the Nazi's using the ashes as fertilizer could very well be true because you don't know the full story, it's possible they chemically treated the ashes in a similar way the website trying to sell you that soil does.

I came across a book called, "the analysis of burned human remains" which very likely has some answers to this question. I'm going to try to get a hold of it and give it a read because it's interesting, I can share what I find if you'd like.

Answer 5

@aaronq
After doing some research, I came across the original source that my teacher probably grabbed their info from:
https://katana17.files.wordpress.com/2014/11/auschwitz-myths-and-facts-404.jpg
It's an article from The Toronto Star in February 1945.
I'm only finding one eyewitness testimony, Elane Geller. A few people in the camp denied her allegations saying that they never heard of anything like that happening in the camp while they were there.
I figured that the Nazis would already have access to better fertilizer. If ashes could be used as a fertilizer, would they be any better than commercial fertilizers?
Let me know what you think and what the book suggests.