I want to know, is there way to test whether a manure is safe to use on plants and does not contain any harmful compounds (alcohol and others) and also free from deadly microorganisms (parasites)?

So far what I do is this - whenever I think that my compost is ready and well rotted and free from parasites (I like to dry it in full sun before use for that reason) I take a little amount of that compost and mix it with water and then pour in on roots of my test plants (usually they are young green wheat plants) and if they stay well for couple of days then I mark that compost as ok to use.

(laboratory way is more costly, so I am avoiding that one)

3 Answers 3


There are three other ways through which you can check Firstly, by visual inspection, you may determine that the compost is crumbly and dark, and it should smell earthy. It might not have completely broken down if it can still be identified as the original elements (such as kitchen leftovers or straw).

Secondly, Temperature test is during the procedure of decomposing composting generates heat. Thus use a compost thermometer and the temperature should be at least 130°F for several days to efficiently kill weed seeds & pathogens.

Third, Germination of seed-take a small sample of Plant seeds in a tiny sample of the compost. Seeds ought to sprout and develop properly if the compost is ripe and completely broken down. You should observe weeds growing alongside your test seeds if there are a sizable number of viable weed seeds.

  • 1
    Stellar answer, "should smell earthy" needs to be bolded out. But one thing to add. Leave it outside and drink a beer in front of it. Zero flies? Fine. One fly? Also fine. More? Not ready yet.
    – Vorac
    Commented yesterday
  • : ) now that strike well on the goal. i think it could be a equivalent to a answer in itself then just a comment . Commented 7 hours ago

I worked at a greenhouse place where their test was to sow lettuce seed. If it germinated the medium was good. I was told lettuce seed is extremely sensitive to contaminants. This will not test for e-coli which is a bacteria not a metal or pesticide residue

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    That wouldn't test for parasites, either.
    – Jurp
    Commented May 6 at 2:43
  • your answer is also adding some value ,that is why i upvoted it ,thanks for your time Commented May 6 at 13:32

It depends whether you are growing plants for human consumption. If you are worried about human parasites present in manure (E. coli, etc.), then there are recommendations available for the proper amount of time to compost manure before it is safe to use, specific to what type of animal it's from, that you should absolutely follow.

If you are just worried about plant parasites, I would tend to avoid using compost made from the same plants that you are growing in the compost or make sure your compost gets hot enough and sits long enough to kill the parasites. Plant parasites are often host-specific, so testing on one type of plant won't tell you if it's safe for another type of plant. Also, a few days will probably not be long enough to incubate a parasite in a plant. But, I don't see the need to test for plant parasites as long as you manage your compost well.

In terms of harmful compounds, if you are worried about human health, then a plant's ability to grow in the compost will not tell you if it is safe for humans or not. You would need laboratory testing. Alternatively, monitor what goes into your compost/manure to make sure there's nothing that would introduce pollutants.

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    i think here is something to gain in everyone's answer but unfortunately i can only accept one answer your answer is also adding some value ,that is why i upvoted it ,thanks for your time . Commented May 6 at 13:36

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