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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
person with a backpack sprayer in a high tunnel

Shaun Bluethenthal fertilizing plants in a high tunnel. Courtesy of Small Farms Program.

*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 here

Happy fertilizing!

Anna Birn

Anna Birn

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 Comments

  1. Avatar Seth on February 3, 2019 at 4:37 pm

    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. Avatar Jim Kennedy on February 4, 2019 at 4:26 pm

    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

  3. Avatar CNY Farmer on February 4, 2019 at 4:35 pm

    Seth:
    Do you know Spanish? (I don’t…)
    If so, this may also be helpful:
    http://caminosostenible.org/wp-content/uploads/BIBLIOTECA/El_ABC_de_la_agricultura_organica_y_harina_de_rocas.pdf

  4. Avatar Martha on February 4, 2019 at 5:41 pm

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

    • Anna Birn Anna Birn on February 6, 2019 at 1:28 pm

      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
      csb258@cornell.edu.
      Good luck!

  5. Avatar Abraham Allotey on February 4, 2019 at 8:01 pm

    This is great and good information

    • Anna Birn Anna Birn on February 6, 2019 at 1:19 pm

      Hi Abraham,
      Glad you like this article!

  6. Avatar Jim Schultz on February 5, 2019 at 7:27 am

    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?

    • Shaun Bluethenthal Shaun Bluethenthal on February 20, 2019 at 12:43 pm

      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.

  7. Avatar Barbara Vaughan Bailey on February 5, 2019 at 11:10 am

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

    • Anna Birn Anna Birn on February 8, 2019 at 12:12 pm

      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!

  8. Avatar ali on August 23, 2019 at 5:57 pm

    thank u very much for such helpful content

  9. Avatar John on October 5, 2019 at 5:00 pm

    Hi Anna,

    Nice piece of work. There are many other ‘foliar’ plant feeding formulas. The “Korea Natural Farming” method comes to mind and also Elaine Ingham’s work.

    A piece summarizing the various practices would be most interesting.

    I have had significant results with plain granite dust and also with ‘fresh’ sea water.

    John – Concord, NH

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