Biochar and Fertilization

Note: This is the first in a series of reviews of websites related to biochar. All of the site review posts will be listed under the ‘Site Review’ category, providing a simple way for readers to locate and evaluate the information about biochar that is available online. If you would like to recommend a site for review, simply join this site and post a comment to any existing site review blog post.

Cornell University has two large sections of their website devoted to biochar topics, Terra Preta and Biochar (Agrichar), both run by Johannes Lehmann, one of the foremost biochar researchers. This review is for the Terra Preta section, we will cover the biochar (agrichar) section in a future post.

The title for this part of the website is Terra Preta de Indio. In his introduction on the home page, Dr Lehmann briefly describes the origin and character of the Terra Preta soils of the Amazon, and describes the implications for carbon sequestration to fight global warming, and soil fertility to reduce depletion of the rain-forest. While this introduction provides a succinct overview, it is written for other scientists and researchers, not the lay public, with sentences like:

In addition to their high soil organic matter contents as mentioned above, Amazonian Dark Earths are characterized by high P contents reaching 200-400 mg P/kg, and higher cation exchange capacity, pH and base saturation than surrounding soils (Sombroek, 1966; Smith, 1980; Kern and Kämpf, 1989; Sombroek et al., 1993; Glaser et al., 2000; Lehmann et al., 2003; Liang et al., 2006).

What he means to say is that the Terra Preta soils retain nutrients better, with more phosphorus and less acidity than surrounding soils, and they have chemical properties indicative of high-fertility.

There are two navigation bars on the site, one across the top with five links, and one in the left column with six buttons — other than the home page, these are not redundant, even though some seem to address similar subject areas. So ‘Research’ leads to a different page than ‘Projects’ and ‘Publications’ is different from ‘References’. The buttons on the left are repeated in the biochar (agrichar) section of the site, and point to the same pages in both.

Some pages do not seem to have been updated since 2005, but the ‘Publications’ page is kept current. That is the most important page on the site, with nearly 100 links to published reports. It is the most comprehensive guide to the scientific literature behind biochar research that I have seen.

The research section is a bit disappointing in that it lists 13 projects, but only six have links to reports, and a couple of those reports are very superficial. One just takes you back to the Terra Preta home page while another takes you to the Biochar (Agrichar) section home page. I’ll describe these in more detail in the next post in this series, which will cover the Biochar (Agrichar) section of the site.

Overall, this site is essential reading for anyone who wants to understand in-depth the background of scientific research on biochar. Despite the name, this site does not provide much information about the cultural origin of the Terra Preta soils, but it is full of information on the soil chemistry.