Growing knowledge (and plants) with Black Gold

Newsletter Issue: 
April 2014

Pink flowers in a garden

Thousands of years ago farmers added “terra preta” or black gold to Amazonian soils to enrich soil productivity. By slowly burning organic materials and burying them underground, ancient farmers were able to create soils that retain nutrients and carbon today. This ancient natural soil conditioning technique was similar to what we now call biochar, a byproduct of modern biofuel production.

The CenUSA Bioenergy project produces biofuels using pyrolysis, a process that transforms agricultural feedstocks at very high heat, into bio-oil used for fuel, and biochar, an almost pure carbon.

Research presented at the 2013 CenUSA annual meeting, showed that biochar increased the ability and capacity of soil to retain water and improve crop yields. No-till corn grown with added biochar had higher yields than corn grown without it.

CenUSA is working with “Extension Master Gardeners” at Iowa State University and the University of Minnesota to see whether biochar could be a useful soil amendment for home gardens and a valuable commercial product for the horticulture industry.

 Master Gardeners studying biochar's impact on garden plotsExtension Master Gardener programs like the one conducted by the University of Minnesota, train individuals who then serve as volunteer Extension Master Gardeners in their communities. Jill Euken, Deputy Director of Iowa State University's Bioeconomy Institute and Director of CenUSA’s Extension and Outreach describes the “pay it forward” effect volunteer Extension Master Gardeners often have.

“There are lots of people interested in gardening who are hungry for information on how to garden well,” said Euken. “Extension Master Gardener programs taught by the Land Grants offer a fairly extensive training program to volunteers who give back by educating others.”

Each summer 50-60 Extension Master Gardener volunteers learn about biochar by testing it on demonstration garden plots growing lettuce, tomatoes, peppers, beans, cucumbers, various flowers and woody herbaceous plants.

The 100 square foot plots are divided into sections, each with a different amount of biochar applied: none (as a control), 150 pounds and 300 pounds.

Lynne Hagen, Extension Master Gardener Coordinator for the University of Minnesota and CenUSA collaborator has said the initial trials of biochar may show an increase in soil quality, although results have been mixed.

Could biochar be the garden phenomenon of the future? Stay tuned for more updates about CenUSA’s Extension Master Gardener demonstration plots!