Biochar Results: Mixed


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Results from the first ever scientific study of biochar by researchers at the University of Southampton have been released. Plant growth was stimulated (up to 100%!) but,

the positive impacts of biochar were coupled with negative findings for a suite of genes that are known to determine the ability of a plant to withstand attack from pests and pathogens. These defence genes were consistently reduced following biochar application to the soil, for example jasmonic and salcyclic acid and ethylene, suggesting that crops grown on biochar may be more susceptible to attack by pests and pathogens. This was a surprising finding and suggests that if reproduced in the field at larger scales, could have wide implications for the use of biochar on commercial crops.

The researchers concluded:

Our findings provide the very first insight into how biochar stimulates plant growth — we now know that cell expansion is stimulated in roots and leaves alike and this appears to be the consequence of a complex signalling network that is focused around two plant growth hormones. However, the finding for plant defense genes was entirely unpredicted and could have serious consequences for the commercial development and deployment of biochar in future. Any risk to agriculture is likely to prevent wide scale use of biochar and we now need to see which pest and pathogens are sensitive to the gene expression changes.

Thanks to Michael Tortorello for the tip.

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  1. So biochar reduces the expression of genes for pest/pathogen resistance in what I assume to be a pest/pathogen free lab. Gene expression is complicated. It doesn’t make sense to assume that the same thing would happen in the presence of pests, or that if it did it would lead directly to crop losses. Also, the Green Revolution was all about increasing yields and dealing with the extremely weak plants you created to get there; at least this would be carbon negative and good for soil structure.

    • This research is just the beginning, I’m sure. A good question about greenhouse vs. field test.

    • Well, we’re not experts, so are talking out of our hats, but personally I’d not see it as a problem. Plant diseases don’t jump to humans/animals, as far as I know. We are impacted when our crops fail, though.

  2. I suppose I did not make myself entirely clear. I was concerned with nutrition and how the biochar would impact the nutrition the food would contain. Can a weakened plant have as much nutrition as a strong plant.

  3. They did not challenge plants with pathogens, nor was there evidence of plant stress, which would likely lead to an upregulation of many plant defense genes. Beneficial microbes in the plant and surrounding soil also supplement the plant’s defensive pathways, and dampen the stress response. Very interesting results that do not merit the concern of disease susceptibility, at least not until they test for disease susceptibility.

    • Interesting results, but yea, plants are so much more complex than what can be found through an experiment in a sterile laboratory environment, this PBS documentary on plants is fascinating, really blows your mind when it comes to how plants communicate and interact with their environment!
      On a personal note on biochar in the garden, since I’ve had a wood fired pizza oven I’ve had lots and lots of biochar to deal with, I’ve been pouring it on my garden plots and mixing it in in mass quantities and this year’s tomato plants are over 7′ tall and producing mass amounts of huge heirloom fruits and really no sign of disease, best year ever, a mild spring has helped, but I think the biochar has contributed to the phenomenal growth!

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