Pot test

Bear Kaufmann. Initially posted April 7, 2008. Updated August 5, 2008.

Images showing trial preparation and radish germination
(Select image to enlarge in Gallery.)

Materials/Methods

Char was Lazzari Brand mesquite BBQ char (due to availability), crushed and screened to 1/8".
No nutrients were added to the char itself or to the soil.
Soil was FoxFarm OceanForest Potting Soil.
Sand used was horticultural sand.
No mycorrhizal fungi were added.
Mixtures range from 0-100% sand, soil, and char in ~16% increments by volume. 90 pots total. 28 combinations with 3 pots each + 6 additional pots at 33%/33%/33% composition. Pots were placed randomly within the tray. Tray was rotated 180° occasionally.
Plants were watered daily by a drip irrigation system.
Plants were removed from pots ~1 month after first watering. Soil was rinsed from roots and roots were patted dry with a towel. Wet weight of roots+shoots was measured (Acculab VI-3mg, 0.001 g precision).

Figure 1. Box Plots Showing Effect of Composition Across Three Transects

Figure 2. Pictures of Radishes at Important Compositions

Results

Plant growth was stunted even for the best preforming plants, likely due to the small pot size. Leaf color varied across different compositions.
A mixture of 33% charcoal and 67% soil had the best growth (176% of pure soil). Aside from mixtures around this level (Figure 1b), high levels of charcoal showed a generally negative effect on plant growth (Figure 1c).

Discussion

The positive interaction effects of charcoal and soil (Figure 1a,1b) are interesting. Assuming charcoal itself provides no integral nutrients to the soil (eg. nitrogen), increasing amounts of charcoal reduce nutrients available from the soil mixture. The effects at 33% char/67% soil, however, show beneficial effects. This could be explained by increased mineralization rates caused by the charcoal causing soil nutrients to be more available to plants. Beyond 33%, the Cation Exchange Capacity of the charcoal may have held the nutrients produced by mineralization, making them less plant available. Since the charcoal was not amended/soaked in a nutrient bearing solution it likely had a low Base Saturation leading to adsorption of nutrients as they became available. Other potential explanations for increased growth along the soil/char transect include alterations to pH or limiting nutrients (eg potassium(?)) provided by the charcoal. The speculative mineralization/CECi model could also explain the effects seen along the sand/char transect. Here, since the sand lacks organic materials and bound nutrients for soil microorganisms to make plant available, the increasing unsaturated CEC may have made any nutrients less plant available.

Author: Bear Kaufmann bear@ursine-design.com

1g Charcoal per seed

50g Miscanthus Charcoal per pot

50g Willow Charcoal per pot

Effects of mycorrhizal fungi and biochar 90 Days

Robert Flanagan, Hangzhou Sustainable Agricultural Food & Fuel Enterprise Co., Ltd. (SAFFE), February 15, 2008

Day 90

Hey Guys, Just got to 90days of my latest biochar trial and wanted some feedback on what data you think I should be taking from this trial? We can clean off the roots and photo as much as possible and do clearly marked side by side photos.

I don't have any funding for this trials so there is a limit on the depth I can go regarding data collection so I'm really looking for a base list. The medium was sterilized subsoil and we used 2Kg soil per tray with three reps of each treatment (I just took the average of each treatment for the attached photo).

Kind Regards, Rob.

Robert Flanagan
Chairman & President Hangzhou Sustainable Agricultural Food & Fuel Enterprise Co., Ltd.

saffechina@gmail.com

Skype "saffechina"

Tel: 86-571-881-850-67 Cell: 86-130-189-959-57

Control
Biochar

Modified Biochar

Effects of mycorrhizal fungi and biochar 75 Days
Robert Flanagan, Hangzhou Sustainable Agricultural Food & Fuel Enterprise Co., Ltd.
(SAFFE), February 5, 2008

I just got to visit my biochar trial at BIOTROP today so I took a few photos to give all you some idea of the profound difference biochar makes to subsoil
Control

Rice Husk Charcoal

Rice Husk Charcoal + VAM

Video:

http://www.youtube.com/watch?v=mvo1w8gFSts

What we're seeing is the plants treated with VAM fungi + biochar are a lot darker green and show more plant growth at the 75day mark so I'll push on up to day90 and see what happens.

Robert Flanagan
Chairman & President
Hangzhou Sustainable Agricultural Food & Fuel Enterprise Co., Ltd.

Skype "saffechina"
Tel: 86-571-881-850-67
Cell: 86-130-189-959-57

CharDB 1.0 released!
Cristelle Braun, January 19, 2008

Hello dear biochar testers!

The first release 1.0 of CharDB is now available at:
http://bionecho.org/terrapreta/chardb/index.php

You will now be able to register your biochar soil amendment trials in a uniform format "CharML" that should facilitate comparisons between the different entries. This will hopefully lead to interesting new conclusions and a better knowledge on the fascinating world of biochar!

Please send any comment, critic, suggestion...to:
chardb@bionecho.org

Your feedback and comments will guide further development of CharDB and CharML!

Sincerely yours,
Chris
brauncch@gmail.com

Potato
This is Puffergas' first test of growing potatoes in switchgrass compost. The potatoes were grown in containers and charcoal was added to the compost.
See link below:
Potato 2007 by Puffergas

The Charcoalab Project: Charcoalab Pot Trials

Robert Flanagan, SAFFE, China, Christelle Braun, Naomi, September 4, 2007

Select image to access album of photos.

Richard Haard: Affinity of fungi and crop plant roots to charcoal
Richard Haard, February 12, 2007

The image below illustrates the affinity of fungi and crop plant roots to charcoal.

Charcoal placed in a fertile garden for a few months showing how crop roots (Swiss chard) and fungi are attached to this medium as habitat