Creating Biochar, Farming Algae; A dynamic duo that combined gives a superior growth media for plants.


Having studied pond fertilization, as practiced in China, it is clear to me that algal growth can be enhanced through the controlled application of organic plant matter to algal pond water. And as a plus, the carbon waste decomposes under water and is sequestered by algae before it escapes into the atmosphere. Instead of creating a greenhouse gas converts the carbon into a usable organic fertilizer, without expending energy.

This is a method of algae production we are studying at OTGE here in Atlanta. By adding fresh grasses, alfalfa, kudzu or clover, etc. to algae ponds systems, we are supplying a local source of CO2, when it is unfeasible to divert exhaust emissions or buy CO2 cannisters as practiced in biofuel algae farms.

Dr Friendly and volunteers, seen in this Algae Lab video in Berkeley California, are doing some cool stuff with algae and spirulina. They’re experimenting with home grown spirulina, converting CO2 from propane generator exhaust and as we practice here, the Algae Lab in Berkeley is using human urine as an organic nitrogen and phosphorus source for growing algae. Dr Friendly likes the urine as it satisfies the need to use fertilizer and it is free and readily available. When asked about blackwater, he prefers to send the bacteria and parasite laden waste to an anaerobic digester where it reduces to a usable methane heating gas plus a sterilized fertilizer.   

What I particularly liked about Dr Friendly’s video was his comment about combining algae plus biochar. Algae is microscopic as are the pores of biochar. This allows for a tight bond of nitrogen and phosphorus rich algae to a potassium rich biochar replete with minerals and trace elements. Such a blend gives us a resource, harvesting algae from water, after it removes nitrogen and phosphorus. By binding algae with biochar, a home grown –super fertilizer – plant media is formed.

Like urine plus biochar, algae plus biochar is on the horizon of the next frontier. Worm tea is there too. All are certain to put life back into our depleted soils and organic aquaponic garden beds.

About drdave

CoFounder of Algosolar, dba Bioponica. Consultant, designer, developer of Biogarden and Incubator Ecosystems for producing organic food and fish, sustainably.


9 thoughts on “Creating Biochar, Farming Algae; A dynamic duo that combined gives a superior growth media for plants.

  1. interesting. How long to perfect?

    Posted by Anonymous | August 3, 2010, 15:43
  2. perfection is never acquired. but we can practice immediately.

    Posted by David Epstein, D.O. | August 3, 2010, 17:53
  3. Major University Admits Hard Science Problems Relating to Algae Have Been SolvedSeptember 8, 2010 by admin Arizona State University Senior Vice President Rick Shangraw recenty said “…algae will “deliver soon” because…most of the hard science problems science problems regarding algae have been solved…Now…it’s largely an engineering problem.”

    Posted by b cole | September 18, 2010, 14:15
    • Deliver what? Biofuel? I’m not convinced that there are efficiencies to convert CO2 to Algae to Ethanol. Rather see it go to use building ecological systems vs polluting systems.

      Posted by drdave | June 20, 2011, 04:26
      • Not for biofuel. Algae is more efficient as a fish food and helps keep pH elevated in biological systems

        Posted by drdave | October 2, 2011, 14:08
  4. I’m intrigued by the combination of biochar and algae farming – as I understand it you are adding fine biochar to the water the algae is growing in. Are you seeing superior algae growth rates with biochar?From what I have read one of the big barriers to effective algae production is light penetration into the growth media. Surely biochar would obstruct light penetration and reduce overall photosynthesis?Also what would you see the overall finished product being used for?

    Posted by Mike | October 17, 2010, 13:17
    • Biochar goes into the beds, though I have read recently where the biochar is used to grow mycelia. Can use biochar in bottom of algae troughs but alkalinity may be a problem for plant growth if not balanced with acid forming. Algae also will lead to alkalinity during day so there needs to be more research in this area. It may be that the pH of the media becomes more acidic as algae in the beds decomposes.

      Posted by drdave | June 20, 2011, 04:22
    • You’ll get enough algae from urine. Biochar may float and yes, will obstruct light. Keep water agitated for more CO2 absorption and biomass growth. Maximize sunlight in top 6cm for greatest effect. Algae is good for feeding tilapia and crawfish but it can raise pH too unacceptably high for accompanying plants. Algae does best when separate from plant beds and used to raise zooplankton and larvae which can be fed to fish, especially baby fry.

      Posted by drdave | November 27, 2011, 11:19
  5. My two favorite answers to some of our biggest problems, together at last! Thanks.

    Posted by Loggy | November 11, 2010, 10:39

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