Healthy Soils for Healthy Vegetables
Written December 12, 2012, published in late December, 2012, all photographs by Kathleen Sayce
|Well-grown vegetables are able to resist weather, diseases, insect pests, and have high levels of minerals, proteins and other plant compounds. This photo of Red Russian Kale was taken in Jim Karnofski’s vegetable garden by Kathleen Sayce.|
Soil CarbonAs with other kinds of plants, vegetable plants need soil carbon. The forms that are the most usable for vegetable plants are not aged wood chips or forest debris, but well prepared compost with humus, and biochar (biologically activated charcoal). Vegetable plants use soil carbon throughout their root growing areas, so gardening practices for optimal plant nutrition incorporate carbon of several kinds throughout the soil profile. Gardeners work carbon into the soil with a rototiller or shovel, add layers to the surface, side dress plants, and amend planting holes. They also fallow garden sections every few years, planting cover crops to put more carbon back into the soil.
Compost with charcoal added is dark colored, and is now ready to go into the vegetable garden. Photo of one of Jim Karnofski’s compost bins.
Making BiocharWhen wood is burned, charcoal is formed during the burning process. If burning is complete, the wood goes to charcoal and then to ash. Starving the fire of oxygen (a process called pyrolysis) promotes charcoal formation and keeps the fire from consuming all the wood. Innovative pyrolysis burners are being developed at backyard and industrial scales to produce large amounts of charcoal with minimal amounts of ash. When the charcoal is wet and cold, it can be added to compost to be inoculated. See HYPERLINK "http://www.biochar-international.org/" http://www.biochar-international.org/ for biochar producing devices. A short video for an introduction to home charcoal making is on You Tube at HYPERLINK "http://www.youtube.com/watch?v=dqkWYM7rYpU" http://www.youtube.com/watch?v=dqkWYM7rYpU .
|Freshly made charcoal is ready to go into the compost pile when it is wet and cold, and broken into small pieces.|