One of the major constraints of biochar soil amendments to improve soil quality and reduce atmospheric CO2 is the type of feedstock (biomass) used in the pyrolysis process. What type of biomass do you think would produce high quality biochar product? Some authors suggested bamboo, rice, and corn/maize feedstocks are excellent biomass products. What do you think?
Jenkins,
biochars made from aniimal wastes may be ideal for improving soil fertiltiy. However, I personally am not sold on the idea of using biochar to improve soil fertility/quality but do acknowledge that this material may have some use as a carbon sequestration agent. As such, hardwood material may be best suited as feedstock.
Hi Renaldo,
Thanks for the comments. Lots of studies referenced the promising potential of animal residues to have high levels of nutrient content when use as biochar. As this approach (which is old) seems to be gaining a lot of scientific attention in the context of soil mangement, CO2 sequestration and climate change many fundamental scientific questions need to be answered in order to advance this approach. Thanks for your comments.
Macedo
I agree with Renaldo Belfon about the questionablility of using charcoal or biochar by itself to increase soil fertility. Long term field experiments conducted here at Bangor University indicate no advantage. However, when ammonia is adsorbed on to charcoal, plants can extract the nitrogen. So, for example, if charcoal is used as a filter to reduce smells from aerobic composting, this will have nutrient value. We have found that rice husk charcoal adsorbs three times as much ammonia as wood charcoal (> 3% w/w), so rice husks (or other cereal chaff) are probably a good feedstock.
To answer your question at least two other questions would need to be addressed. First, what will that biochar be used for? The final application to a soil (biochar effects vary strongly for different soil types) is only one of many uses (please, follow the link below) and different uses require different qualities. Second, where will the biochar be used? Financial transportation costs might not always be an issue; but, to strengthen local and regional cycles (material, energy, money) the biomass should come from not too far away. So it would be best to examine the area where biochar could be of use and to look for biomass available in abundance and then to use that.
http://www.ithaka-journal.net/55-anwendungen-von-pflanzenkohle?lang=en
Hi Daniel,
Thanks for the link and for also contributing your thoughts and experience with Biochar. Just for informational purposes, I am currently implementing a 6-7 month field research in the Vientiane Plains in Laos at the International Water Management Institute. My central hypothesis is to see whether or not regenerative soil amendments such as biochar, manuring and the mixture of both methods have any effect on enhancing soil nutrient status and water retention. Just to give you some insights on the nature of rural farming here in the study area, smallholders rely on rainfall for cultivation, meaning during the hot dry season there is no cultivation. The dominant crop cultivated here during the rainy season is rice. However, lettuce, cabbage, tomatoes, cucumbers, edible herbs, watermelon, etc are some of the vegetable crop cultivated during both the hot and wet seasons.
For my study, I am conducting experiments, which will involve Morning Glory and Lettuce (two widely grown vegetable crops that form an essential component of the diet of smallholders) here. Irrigation will be applied to all treatment including the control (farming as usual, which is usually done by burning rice bran on the target vegetable bed at least a week before cultivation and it will interest you to know that without further application of animal manure or fertilizer, plant growth is amazing).
Regards,
Macedo
Oh. I forgot one more thing. Here is the link to my blog should you be interested in following updates from the field. I have not posted any update for the past week. So, please expect that shortly.
http://jmacedo1.wordpress.com
We used rice husk biomass to produced the biochar for the study based on its availability in the study area and cost effectiveness to the farmers.
Hi
at least biochar moisture should be less than 10%, and ash content should also be less than around 5%
Hi
Yes I a gree with Farhad and from this point of view Miscanthus could be a good promising biomass crop for the production of biochar
Good Evening ALL ....
I am also working on Biochar, I conducted some pot trials on Rice plant biomass derived Biochar. I found it very satisfactory in my observations. The same will be used in our field experiments, that soil has low nutrient status, hope this will work.
Hard bio materials are producing good quality biochar with high recovery %. Biochar produced with high pyrolysis temperature gives stronger level of recalcitrant carbon with lesser recovery of carbon and nutrients . Biochar of animal wastes contains more nutrient per unit quantity at lower pyrolysis temperature than other bio residues.
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