Submitted to: Greenhouse Product News
Publication Type: Trade Journal
Publication Acceptance Date: 6/14/2014
Publication Date: 8/1/2014
Citation: Altland, J.E. 2014. Should biochar be used in container substrates?. Greenhouse Product News. 24(8):14-21.
Technical Abstract: Biochar is charred organic matter that remains after a process called pyrolysis. Pyrolysis is a thermochemical decomposition of organic matter. In this process, organic matter is subjected to extremely high temperatures (200 to 800 °C) in the absence of oxygen. The history of biochar use begins in the Amazon Basin of Brazil. Soils of the Amazon Basin are typically highly-weathered, grey-colored, infertile, and generally poor for growing crops. In the 1870s an American geologist, James Orton, described large patches of the Amazon Basin as having ‘black and very fertile’ soil. It was determined that these areas of black soil, called 'terra preta' by local peoples, were the result of land clearing (with fire) by indigenous peoples over many thousands of years. As an extension of this archaeological discovery, it was shown that previously infertile soils in the Amazon Basin, if amended with high rates of biochar, were more fertile and conducive to crop growth. Biochar amendment to already fertile field soils is not as beneficial as amendment to infertile soils. Biochar amendment to soilless substrates, which are typically irrigated on demand, fertilized heavily, and engineered to have ideal physical properties, has also shown to be relatively ineffective and providing little benefit.