I received an interesting article this morning from the USDA about some new research into glomalin, a sugar-protein produced by beneficial soil fungi. Here a few interesting tidbits I picked up.
- Soils with native grasses had higher levels of glomalin than those planted with non-native grasses. This makes perfect sense since glomalin is produced by beneficial soil fungi (known as arbuscular mycorrhizae) that have a symbiotic relationship with plant roots. (Fact is more than 80% of the plant species benefit from symbiotic interaction with soil microbial life.)
- Soils with high glomalin content are richer (in terms of plant nutrition) and less erosion prone than soils with lower glomalin content. This is because the glomalin helps soil particles stick together, forming aggregates that are more stabile in the presence of wind and water pressure.
- But there is also a carbon sequestration effect that is significant. Plants remove carbon dioxide from the atmosphere (just as mammals like us remove oxygen) to fuel photosynthesis. Some of the results of this process -- on which all higher life on Earth is dependent -- end up in the plant roots, where the root fungi process some of the resulting organic compounds into glomalin.
General estimates have about 1,500 gigatons (yes, that is billion of tons) of carbon is stored in the soil. If the efficiency of that storage process could be improved by even 10%, that is another 150 billion gigatons removed from the atmosphere, which would have a more profound effect on the greenhouse gas content than just about any other action. Not all of it will remain in the soil of course -- especially in the case of switchgrass, on which the article focuses, because it would be converted into ethanol and then burned to feed our passion for the (formerly) open highway -- but still, it would be a help.
That is why restoring wetlands, prairies and savannahs -- as well as degraded forests -- especially in the tropic latitudes, where growth is fastest -- is so important. And restoring our farming methods as well. the researchers also found that glomalin levels were a good indicator of how "soil friendly" farming practices on the studied land were. Decades of research at the Rodale Institute have shown that organic farming stores far more carbon in the soil than conventional farming and thus helps fight globa warming.
To read the whole report, see the online version of the July Issue of Agricultural Research.
