Guest Column: Biochar
Our soil is being degraded, and our actions may be killing it. In growing regions like California, we commonly sterilize soil to eradicate diseases, blights and insects. When soil is sterilized, sometimes all its life is destroyed. Constant planting of the same crops on a piece of land removes minerals and nutrients required for healthy and vigorous growth. When you cut down trees, too, eliminating their roots, leaves and droppings, you deplete the soils.
Between 15 and 19 chemical elements are needed for fertility, and we may be adding back only six or seven of them, causing a decline in the fertility of the soil and the nutritional value of our food and forage crops. We need soil that is teeming with life. The more moist and aerated it stays, the more diversity persists in the soil biota and the more resistant the plants become to infection and infestation.
Fortunately, we have solutions. One is horticultural charcoal, or biochar. It is a porus substrate with a large surface area that rapidly holds and slowly supplies water. It allows air to open tight soils and rapidly capture fertilizers and nutrients so that they become available to the plants. It provides a refuge for microbes from the predators that feed on them.
Biochar could be very beneficial in coastal areas that have been flooded with seawater, like New Jersey and Florida. Encouraging results from these areas support early Australian biochar studies on the successful cultivation of food crops in soil with high levels of salt around the Dead Sea area.
I have been experimenting with biochar for the past few years. It conditions the soil so that I can work it with my hands instead of tools. It maximizes my compost and instead of letting rain wash away nutrients, biochar holds them in, like a nutrient “bank account” that is saved up and spent on demand based on what the plants need.
Charcoal needs to be “charged” or treated. It can be charged naturally with urine, manure or compost tea, or synthetically with water-soluble nutrients. It can be inoculated with beneficial soil microbes and fungi that help fix nitrogen from the air, transform minerals into a form that plants can use, or help defend plants from pests. Based on what each plant needs, I supplement my biochar with compost, woodchips, fertilizers and mineral supplements. I use no herbicides, fungicides or pesticides. My fertilizer usage has been cut in half, and rarely do I need to irrigate.
As a soil conditioner, biochar counteracts disease and stress caused by heat, cold, drought and flooding because it helps the plant build up its immune response systems, rather as probiotics do in the human intestine. Before I used biochar, my corn plants would fall over in the high wind we frequently experience. Now my plants seem to have a tough “you can’t take me down’” attitude, and I have no potato beetles, bean beetles, stink bugs or grubs. I have a wonderful, teeming community of earthworms and plenty of fungus. This is my fourth year successfully growing tomatoes, potatoes, peppers and squash in blighted soil using biochar. Recent reports from Maine, Quebec, and Prince Edward Island contain findings that echo my experience.
The 2013 North American Biochar Symposium will be held at UMass-Amherst October 13-16. For more information, visit http://symposium2013.pvbiochar.org.•
Tadeusz Wysocki, a “semi-retired” chemical materials and process engineer, lives and gardens in Wales, Mass.