Biochar can benefit your soil, but only if properly prepared prior to application. In November 2007, scientists at the USDA National Laboratory for Agriculture and the Environment (NLAE) in Ames, Iowa, began multi-year field trials to assess the effects of biochar on crop productivity and soil quality. Scientists amended almost 8 acres with biochar made from hardwood. Twelve plots received 4 tons per acre; 12 were treated with 8 tons per acre.
They found no significant difference in the three-year average grain yield from either treatment. Other USDA field and laboratory studies in Idaho, Kentucky, Minnesota, South Carolina, and Texas showed hardwood biochar can improve soil structure and increase sandy soils’ ability to retain water. But soil fertility response was more variable.
USDA scientists violated four key principles for biochar use: they used 1) bulk char, in one large load; 2) raw, uncharged char; 3) sterile, uninoculated char, with only a tad of microbial life; and 4) synthetic salt fertilizer, tillage, and other antibiotic practices.
Biochar, like water, is best added in a series of small doses so soil has adequate time to distribute and digest it. After all, soil may get 25 or more inches of rain a year, but not all at once in a single event. We already know from research in the Amazon that dumping 5, 10, or even 20 tons of raw char all at once into poor soil retards plant growth for one year and maybe two. After that, though, plants erupt in impressive, vigorous growth.
But a dip in yield isn’t acceptable for production agriculture. Farmers can’t wait a year or two to harvest a profitable crop. Professional growers need fast response and strong stimulus to growth. Economics and handling logistics require convenience and low cost, with vigorous growth from minimal applied material.
Fortunately, we are learning how to prepare char for optimum results in soil and on crops. Biochar research in America is hardly 10 years old, but solid research shows that properly prepared, intelligently applied biochar has dramatic effects on soil structure and plant growth at as little as 500 pounds per acre.
There are four fundamental steps for optimally preparing biochar for use in soil: moisten, mineralize, micronize, and microbial inoculation. Continue Reading →