This is year three of our experiments using biochar as a soil amendment.
Year one, 2021, focused on short term benefits. It took place at two locations in the
Grand Valley, each with four plots planted with the same set of plants – bell peppers,
chili peppers, eggplant and kale. Each of the four subplots had different soil
amendments: none (control), compost-only, compost plus 10% biochar, and compost
plus 20% biochar.
2022 expanded the study to six locations across the Grand Valley to assess the effects
of biochar in different soils. Last year presented several challenges including a late
freeze followed by high winds and extremely hot weather, weakening the very young
plants and eventually killing several others. A research report for the 2022 experiment is
still in process. The results of that field experiment indicate that the amendments
containing biochar give higher yields.
This season we narrowed the study down to one location. Colorado State University
(CSU) Orchard Mesa Research Station has generously donated space for the project
consisting of five approximately 3′ x 13′ garden beds.
Assessing and applying the required amount of nitrogen (N) for each crop was especially important to ensure neither too much nor too little (N) affected the results of the study. We have not used any sources of primary plant nutrients other than those contained in the biochar/compost and compost-only materials we added to the existing garden bed soils.
The following is taken from the United States Department of Agriculture (USDA)
California Climate Hub and the Working Lands Innovation Center:
There is growing excitement about biochar use as an agricultural amendment to
improve soil health and sequester carbon. Biochar is a carbon-rich material, similar to
charcoal, made under low oxygen conditions with high temperature conversion of
biomass feedstocks such as wood, nutshells, hulls, or manure. In addition to promoting
soil carbon storage, biochar may provide benefits to growers such as improved yields
and enhanced water and nutrient use efficiency.
The potential benefits from biochar are a function of the feedstock and production
method, soil type, climate, and cropping system. Although biochar amendments may
provide benefits, there are potential drawbacks and growers may need assistance in
making informed decisions on how and when to apply biochar to their fields.