Can Biochar improve off the shelf high end compost? 17 to 23% improvements on Fox Farms “Ocean Forest”?

I am posting this with permission of Josiah Hunt of Biochar Hawaii.  You can find the original blog entry on his website.

Improved Growth with Biochar and Fox Farms Part II

The Case of the Very Green Onions:
Plain biochar was added to Fox Farms “Ocean Forest” potting soil to see if there were significant improvements in the plant growth response.  After four weeks initial data was collected – I cut the lettuce and weighed it.  After another 8 weeks went by the remaining lettuce and green onions were cut and weighed.

Fox Farms “Ocean Forest” potting media is generally regarded as one of the best organic potting media’s available.  The test was; can we improve the best by adding biochar?  The results were good.  As you can see in the picture here, the green onions were larger and greener where biochar was used (the plants on the right).

Here are the individual weights of the plants from each pot cut at level with the soil media and immediately weighed:

Green Onion:
(Control) 8g, 5.3g, 10.1g, 3.5g, 4.0g, 2.7g, total: 33.5g
(Biochar at 5% by volume) 6.6g, 10.5g, 5.2g, 5.4g, 4.0g, 7.6g, Total: 39.3g
17.3% increase from control to biochar 

Beyond the weight of the green onions I find it very interesting how much greener the biochar group was when compared to the control.  There was 0% nitrogen in the biochar added, yet the plants grown with it are noticeably greener.  Less loss of N?  Greater bio-assimilation of unavailable N?  Improved plant-microbe-nutrient relations?  All the above?  If so, which to a greater extent?

(Control) 14.4g, 12.9g, 19.9g, 17.8g Total: 64.8g
(Biochar at 5% by volume) 20.9g, 19.6g, 21.9g, 18.0g, Total: 80.2g
23.7 % increase from control to biochar
It is hard to see in the picture, but the tallest of the lettuce bolts are in the biochar blended group of pots on the right hand side.  Not the best looking heads of lettuce I have ever seen, luckily comparison was the goal, not dinner.

The biochar used in this trial was un-amended.  Nothing but fresh biochar was added.  No fertilizers were used.  The only water was what fell from the sky.

After the tops were cut off and weighed the green onions were transplanted to the garden.  I had some with my eggs for breakfast, they were 100% tasty.
Thanks for you interest,
– Josiah Hunt

For information on the first part of this experiment please visit the initial posting Here.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: