Sciencemadness Discussion Board

Horse manure

danton - 26-6-2025 at 00:40

A horse mad young teen also has an interest in biology. I’m wondering if this might be an opportunity to undertake some supervised testing of the manure composition? Any suggestions for how this be approached, or similar ways to engage?

Thanks

Sulaiman - 26-6-2025 at 01:05

Quote: Originally posted by danton  
... I’m wondering if this might be an opportunity to undertake some supervised testing of the manure composition?...
test for what ?
(chemical, viral, microbial, nutrition ....)

Honestly, chemical analysis of simple mixtures is not easy
there must be thousands of compounds in poop
so a general analysis would be a huge project.

I suggest that if there is not a commercial test kit
for the components that you want to investigate
save that part of your project for later.

any direction that you take will require research,
first you have to research which areas to research :)

For me, direct approach is the easiest path,
eg ask horse owners what services they may want, but are unavailable or too expensive.
This will also make 'sample' collection seem a little less 'odd'

Antigua - 26-6-2025 at 01:19

This is a very interesting topic. The answer depends on what you actually want to do.

Do you want to analyze the crude composition eg:
- inorganic material
- metabolites
- undigested material

Or do you want to analyze the particular composition of organic compounds in it?
- indoles
- organic polymers (cellulose, maybe bacterial RNA?, epithelial cell components?)

For the first you would want to use mainly physical methods (centrifuge, simple solubility differentiation)
For the second more advanced stuff (GC-MS, PCR)
But maybe you could work out a method to extract the organic small molecules and then run an analysis based on TLC RFs, which would be much simpler.

You're in for a large project though. There have been publications on this as it's an important veterinary marker.

danton - 26-6-2025 at 01:26

My original post wasn’t very clear. I’m pondering whether we could perform an analysis to determine the nitrogen, phosphorus, potassium content and total solids?

Thanks

bnull - 26-6-2025 at 03:38

Try the first few pages of this book: J. B. Cohen, Practical Organic Chemistry. It will give you an idea of how the tests go. Older organic chemistry books (late 1800s, up 1920-something) were somewhat deep into that kind of analysis. It is straightforward to perform and I'd bet that the Department of Agriculture has something on it.

Also: Managing and composting horse manure. Check out the sources.

You're not trying to use horse dung in place of cow manure, are you? Twenty, twenty-five years ago, my mother used to buy manure from some farmers and, occasionally, a dishonest bastard sold mixtures with fresh horse manure. The plants didn't like it at all, not to mention the stench. It must rot for a while, different from cow's.

Sulaiman - 26-6-2025 at 06:19

NPK test kit eg https://www.ebay.co.uk/itm/256723040769
(you would need to dilute your sample to be in measurement range)

evaporate to dryness a weighed quantity of fresh manure and weigh the dry remainder.
..........
my neighbour used to grow heritage roses,
one year he cheaped out and bought fresh horse manure,
horsetail weeds took over his garden the same year, mine the next.
so, DEFINITELY only use manure that has been cooked, or well rotted.

Horse manure

danton - 29-6-2025 at 01:55

Thanks for all of the replies. Very interesting and has given me a few ideas. I’ll find the referenced books first and have a read. I’ll report back if we make any progress.

zed - 16-7-2025 at 16:09

Umm. As I recall, I once had a young scientist inform me that Horse-Manure was excellent for growing mushrooms.

Gotta sterilize it by heating it, in mason jars, in a pressure cooker ( standard canning procedure). Then, when things have cooled down; the manure is inoculated with mushroom spores.

Seems like he told me he was growing Psilocybe type mushrooms. Not a legal procedure in all jurisdictions, but quasi-legal in my current State of residence.

Seems to me that horse manure is probably "hotter" than cow manure. Horse manure being collected from horse stalls; where it has been peed on and thereby enriched with urea.

mayko - 16-7-2025 at 18:15

I did a science fair project much like this in 7th grade; made it all the way to state. I had a few test strips but iirc only the pH paper gave anything meaningful. I also measured moisture content (by massing a sample before and after drying) and mineral content (by burning the dry sample with a blowtorch and remassing the ash).

We piled the manure over a PVC pipe beforehand, so that I could also measure its internal temperature as it decomposed.