Richard Stein: Is ‘biochar’ right fertilizer for our times?
To the editor:
We all know of problems related to the increase of carbon dioxide in the atmosphere and the consequences of global warming. Another problem is the deterioration of America’s soils and its consequences for the growth of food.
This is occurring at a time when food needs are increasing.
Soil deterioration is often a consequence of poor farming practices, such as overuse of farmland and improper crop rotation. The organic content of soil has decreased and in attempts to increase productivity, there has been overuse of synthetic fertilizers.
To combat this problem, means such as no-till and organic farming have been attempted. We suggest a procedure being explored locally — the use of biochar, a form of charcoal prepared by hearing biomass with restricted availability of air.
The use of biochar as a soil amendment is far superior to that of synthetic fertilizers, in that the latter require energy to manufacture and their run-off may pollute waterways.
By using biochar along with these fertilizers, the amount required is less, as little as half, as the biochar binds the fertilizer and reduces run-off. Most believe the added biochar remains in the soil for many years. Also, it has advantages over adding biomass to the soil in that the biomass degrades in a decade or so and releases its carbon to the atmosphere.
If one converts the biomass to biochar, about half of its carbon is converted to elemental carbon that is relatively inert and does not get released to the atmosphere. Other advantages are decreases in water requirements for irrigation and absorption of toxic materials from the soil, presenting them from entering the growing biomass.
Biomass preparation is a simple technique. Information can be obtained at the website of the Pioneer Valley Biochar Initiative at pvbiochar.org. Samples can be obtained from by emailing Judith Gillan at email@example.com or T. Wysocki at firstname.lastname@example.org.
Richard S. Stein
Richard S. Stein is a professor emeritus in chemistry at the University of Massachusetts Amherst.