The fruits have been harvested and weighed, so my first experiment with biochar (begun in May and described below) is ready for final report. The plants in the layered crater grew faster early on and bloomed earlier, too, but in the end the biochar bed won the contest. With about 15 pounds of butternut and delicata squash from the layered crater, and 20 from the biochar bed, I win all round.
But I still have questions. Was it simply later blooming that made the difference, or did the plants in the biochar bed produce better pollen or other reproductive organs? There are still many questions to ask and answer about biochar, so next year I'll run another experiment and keep you posted. Meanwhile, let us know about biochar studies you've been conducting in your back yard.
A few months ago I wrote about biochar for Mother Earth News, which scientists all over the world believe may be a boon to agriculture and environmental restoration. I wondered: would biochar made in a trench in the garden benefit vegetables?
Last fall, I began my experiment by establishing two new beds:
>The Biochar bed was dug 14 inches deep, then piled 4 feet high with hard-to-compost materials including brambles, invasive weeds and shrub prunings. I burned the stuff about halfway, then snuffed the fire with moist soil. A second burn was done 6 weeks later. In spring, as I filled in the last few inches of the trench with reasonably good soil, I mixed in a standard application of a balanced organic fertilizer.
>The Layered Crater bed was dug 14 inches deep, then filled in with alternate layers of garden compost, soil, old mulch, more soil, and so forth, along with the same amount of organic fertilizer used in the biochar bed.
Two seedlings each of ‘Delicata’ and ‘Early Butternut’ squash were set out in each bed on May 20. Since then, we have had unusually abundant rain.
As of June 11, the plants in the Layered Crater are noticeably larger than the ones in the Biochar bed. Stay tuned! Updates to come, along with details on the next Biochar experiment – studding buckets of curing compost with chunks of charcoal from the wood stove.
Above, two species of winter squash appear to be growing well in a Layered Crater.
Below, the same squash are falling behind in the biochar bed.