In the first study of its kind, research undertaken at the University of Southampton has cast significant doubt over the use of biochar to alleviate climate change.
Biochar is produced when wood is combusted at high temperatures to make bio-oil and has been proposed as a method of geoengineering. When buried in the soil, this carbon rich substance could potentially lock-up carbon and reduced greenhouse gas emissions. The global potential of biochar is considered to be large, with up to 12 percent of emissions reduced by biochar soil application.
Many previous reports have shown that biochar can also stimulate crop growth and yield, providing a valuable co-benefit when the soil is treated with biochar, but the mechanism enabling this to happen is unknown.
Professor Gail Taylor, Director of Research at the University's Centre for Biological Sciences and research colleagues, in collaboration with National Research Council (CNR) scientists in Italy and The James Hutton Institute in Scotland, have provided an explanation why biochar has this impact. They have published their findings in the journal Global Change Biology Bioenergy.
They found that when thale cress and lettuce plants were subjected to increasing amounts of biochar mixed with soil, using the equivalent of up to 50 tonnes per hectare per year, if applied in the field, plant growth was stimulated by over 100 percent. For the first time, the response of more than 10,000 genes was followed simultaneously, which identified brassinosteroids and auxins and their signalling molecules as key to the growth stimulation observed in biochar. Brassinosteroids and auxins are two growth promoting plant hormones and the study goes further in showing that their signalling molecules were also stimulated by biochar application.
However, the positive impacts of biochar were coupled with negative findings for a suite of genes that are known to determine the ability o
|Contact: Glenn Harris|
University of Southampton