I’m always skeptical of what I call the “notions and potions” school of gardening. Every few years there is some new substance touted as the secret to a lush vegetable garden. One such substance is biochar, a kind of charcoal used as a soil amendment.
The University of Minnesota Extension service is in the midst of a four year study to test the use of biochar in vegetable gardens.
Preliminary results (which you can read here) show benefit for some crops such as kale, but a decrease in growth for others such as asparagus.
The more we learn about biochar, the more we need to learn. From an overall standpoint, there appeared to be some benefit of using biochar in the nutrient-depleted sandy soils at the Andover site for some crops. Yet, there was a decrease in growth in some plants and higher yield in others. In the Arboretum and St. Paul campus sites, we noted similar results, but more crops seemed to decline with biochar than without it.
There’s nothing new about biochar. It was in use by native peoples in the Amazon region before Columbus. Hopefully this study will help clarify what types of soils and what crops benefit most from its use.
Do you have an opinion about Biochar? Leave a comment . . .
And thanks to Michael Tortorello for sending me the link.