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Recipe for Success: Brew Your Own Biofertilizer

Have you thought about switching to a biofertilizer? Full spectrum biofertilizers like “Super Magro” have simple ingredients and can prevent yield loss. Through plant nutrition, biofertilizers reduce disease, pest, and physiological stress, to maximize your crops’ performance. After brewing the base recipe, Super Magro can be tailored by adding specific mineral salts to fit your needs.

Cornell Small Farms’ own Shaun Bluethenthal, an agronomist and research farmer describes the process of how to make Super Magro biofertilizer.

Super Magro was conceived in Latin America during the 1980s by farmer Delvino Magro with support from professor Sabastiao Pinheiro of the Juquira Candiru Foundation, in Rio Do Sul, Brazil. The Super Magro formula was intentionally released without patent or intellectual property claims as an empowerment tool for independent farmers.

The base formula for Super Magro combines seven key components, which ferment over four days. The result is a nutrient-rich liquid, complete with organic and amino acids, and essential minerals in plant-available form.

Base Formula*  

  •  Untreated water
  •  Fresh cow dung
  •  Molasses
  •  Whey (or milk)
  •  S. cerevisiae (yeast)
  •  Wood ash
  •  Rockdust

*see supporting documents for complete formula and schedule

The beauty of this recipe, and biofertilizers in general, is that they harness naturally occurring microbial processes and use them to convert essential mineral ingredients into available plant nutrients. Specialized rumen-microbes, delivered via the cow dung, use the readily available sugars in the molasses to perform anaerobic fermentation. After four days of fermentation, context-specific salts can be added to the mixture. Super Magro uses nine specific salts, each of which plays critical roles in plant health, to create a broad-spectrum complement of essential minerals.

Now that you have an understanding of the mechanisms behind this type of biofertilizer production, you can tailor-make your own fertilizers specific to the needs and stages of growth of your crops.

Since the recipe is scalable and requires no outside energy source for its manufacture, it can be a great fertilizer option for small farms, homesteads, and even urban farmers. During this type of biofertilizer process, gasses expelled through the air-lock during the fermentation process have no detectable odor. Also, at the completion of a successful fermentation, the end product no longer has a raw manure smell. This bonus is especially useful for farmers and growers that have neighbors within close proximity.

In addition to its robust nutritional profile, Super Magro is also a cost-effective alternative ( > $2.50 per acre) to commercial fertilizers. Some farmers may already have many of the ingredients on hand. Even if you don’t, the ingredients are common enough that they are readily available and inexpensive.

Read more about Super Magro at:

Happy fertilizing!

Anna Birn is a junior studying Agricultural Science with a minor in Community Food Systems. She works as a student assistant at the Cornell Small Farms Program, supporting its communications and outreach efforts.


15 thoughts on “Recipe for Success: Brew Your Own Biofertilizer

  1. Seth says:

    This looks very interesting for my needs. I have a coffee and dairy cattle farm in Guatemala. However, I would appreciate a detailed listing (with specific quantities) of the ingredients in the recipe, especially the mineral components. Thank you.

  2. Anna Birn says:

    Hi Seth,
    We are so glad you found this article helpful. Here is the link to a more detailed recipe including quantities and time schedules.
    Good luck with your dairy and coffee operation!

  3. Jim Kennedy says:

    We are looking for help to produce fish hydrolysate. Can you suggest a contact person or available research for a formula.

    Thank you,

    Jim Kennedy

  4. Martha says:

    Any chance you can add information about the mechanics/fabrication of the vessel and the hose etc.?

  5. Abraham Allotey says:

    This is great and good information

  6. Jim Schultz says:

    Aren’t there food safety issues due to the raw manure? I imagine the fermentation might take care of some of the potential pathogens but I don’t see it passing a certifier without the standard 90/120 day wait period. Thoughts?

  7. Barbara Vaughan Bailey says:

    Thanks for this. Once this is brewed and rested, will it stay good for use throughout the season?

  8. Anna Birn says:

    Hi Abraham,
    Glad you like this article!

  9. Anna Birn says:

    Hi Martha,
    I would direct your question about crafting the vessel to Shaun, who created the instructional video. Shaun can be reached at 607-255-9911 or
    Good luck!

  10. Anna Birn says:

    Hi Jim,
    Our recipe for fish hydrolysate, as well as other D.I.Y fertilizer recipes can be found in the “Recipe to Regenerate Your Small Farm” article.
    For more information on fertilizers you could also check out Cooperative Extension’s fertilizer page:
    Hope this is useful!

  11. Anna Birn says:

    Hi Barbara,
    Yes! As long as it is kept away from extreme temperatures and prolonged light exposure, Super Magro can be stored and used all season long.
    When transferring Super from fermentation container to storage container, leave the lid loose on the storage container for a couple days to allow for metabolic offgassing. After that, Super can be kept in sealed opaque containers to be used as needed.
    Hope this helps!

  12. Shaun Bluethenthal says:

    Jim Schultz,
    This fertilizer is not exempt from the 90/120 day preharvest application interval, per the National Organic Program (NOP) §205.203. While there was a Petition in November of ’17 to amend §205.203(c) to include anaerobic digestion products, termed ‘digestate’, only the Motion to classify anaerobic digestate as nonsynthetic was passed. The motion to alter the language of §205.203(c) to permit exemption of anaerobic digestate from pre-harvest application intervals did not pass. In addition, the mineral additive components in this formula cannot be used without a documented deficiency, per NOP regulation.
    Great questions, Jim.

  13. Laura says:

    What are the minimum temperatures that this formula needs in order to properly ferment, and what would you recommend for those of us in cooler climates where outdoor temps don’t reach the 70’s until well into the growing season? Can we ferment at lower temps, with the understanding it might take longer, or is 70F the minimum? Thanks!

  14. ns749 says:

    Hi Laura,
    I would direct your question to Shaun, who created the instructional video. Shaun can be reached at 607-255-9911 or
    Good luck!

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