Dear Dereje Ashebir

The air tight packing is the good manner to preserve Organic Fertilizers. For Preservation of Organic Fertilizers; the organic Fertilizers are the colony of anaerobic bacteria if you add something wrong then the bacteria will dia. For preservation and odour you can add only 100-200 mg/ kg of sodium benzoate within your organic fertilizers. The methanol can also be used for that purpose but quantity of methanol should be 50-100 mg/kg of Bio fertilizers, But after add methanol the container should be air tight for min.  5 hrs. Then use organic Fertilizers.

Regards,

Prem Baboo

You can conserve organic fertilizer without adding classical preservatives but by lactic acid fermentation. Just add an easy digestable C-source, mix it put a fermentation lock and ferment it a week or two at room temperature. The smell will change to an aromatic-sour one and gas production will be stopped by lactic acid conservation. By that way you inactivate a bunch of pathogens en passant.

For more information see attached publication.

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0118230

I agree with the answer by Hendrik A Scheinemann .

Where its leagl you can try gamma irradiation. The IAEA in Vienna has lot of literature on this issue, for all other cases Hendrik A Scheinemann provided the best solution.

Natural Preservatives like Onion Special  and UBI Humic Zyme Plus Granules are often used to increase uptake of produced organic fertilizers

Interesting discussion on a good and practical question.All the options suggested need careful thinking for practical use.Addition of any preservative which is not harmful to microbes is o.k.as it will not be harmful to animals or humans. Suppressing other harmful microbes using a  beneficial organism is a good approach.It is like our eating curds to suppress the harmful organisms in our gut/intestine.I appreciate the work of Scheinemann probably based on ancient wisdom.

I thank you all for the comments.

I should have been clear with the "Organic" fertilizer I am referring to. It wasn't farm manure or Sewage sludge. We are using industrial processed ingredients which are accepted for organic fertilizer such as seaweed extract, yeast extract, alfalfa and fish liquid. two or more of these ingredients have been used in combination in different non-organic formulation without any problem. In the current formulation, there is excessive gas production inside the bottle and produces unpleasant smell when open. Could you please see my question from this perspective?     

Dear Dereje Ashebi  

Preservative for organic fertilizer (280 results) see:

http://www.alibaba.com/showroom/preservative-for-organic-fertilizer.html

Regards

Dereje, if I understand it that extracts of those are used in different combinations, did you add any chelating agent? surfactant or micronutrients? Which of those if yes as an informed suggestion is possible only if these are known.

Goodluck

Eucharia, micronutrients amino acid chelates are used, but not surfactant.

Thanks

Dear Dereje Ashebir Bezabih,

the gas production and bad smell you mentioned, sound to me like a clostridia-driven-fermentation by this kind of remote 'diagnostics'. It makes sense if the protein concentration is pretty high within the substrates, due to clostridia out-compete lactobacilla in high protein environments.

Try to ignite a S M A L L (!!!) gas fraction of it to find out if the flame is more Hydrogen like or more Methanlike. If it produces biogas you might use this wastes for energy production. If you don't want any kind of biogasproduction increase the easy digestible sugars which may preferred by lactobacilli. But if the initial lactic acid bacteria concentration is to small the clostridia will 'win' the race anyhow. You might consider using a preservation-starting culture from comparable food substrates. You may be able to use an adapted starting culture out of your waste substrates afterwards, if it worked out.

Please inform us if those suggestions work.

With best regards,

Hendrik

What about hydrogen peroxide? 1-3% of solution weight.

Dereje Sir,

have you tried any preservative suggested for organic fertilizers? which one you will recommend?

Thank you

For preservation of Liquid Biofertilizers. Addition of any preservative should not be harmful to microbes also should not harmful for animals or humans. However following additive can also be used sodium benzoate , methanol ,glycerol , polyvinyl alcohol , cassava starch, sodium alginate, Niacin

I suggest sodium benzoate

Lime water can also be added and also keep in a cool and dry place and inside an air tight container