Nebraska Forest Service & Douglas County Biochar Amendment

By Heather Nobert with Justin Beck

In 2015 the Nebraska Forest Service and the Douglas County Environmental Services teamed up for a five-year project to amend urban soils at the Douglas County Health Center. The project was designed with several goals in mind:

1. Improve soil quality at a compacted, urban site using biochar
2. Evaluate soil physical and chemical properties between 4 treatments and a control
3. Evaluate leaf tissue properties between the biochar treatments and a control
4. Make recommendations for best practices for amending compacted, urban soils with biochar.

Soil and leaf tissue samples will be taken for 5 years following the application of biochar. As of late summer, 2017, increases in soil organic matter and phosphorous were observed across all soil treatments that had been applied with biochar. Some differences in pH, cation exchange capacity, and various other chemical properties of the soils were observed but varied by treatment with no clear trend. At this time no trends were observed in the leaf tissue samples.
When this trial concludes in 2020, we hope to have significant data to support the use of biochar as an urban soil amendment. We also hope to determine if leaf tissue samples are a viable measure of improvements in soil quality. Several results and developments have taken place as of 2019 with regards to this project:

• Increases in soil organic matter.
• Increases in cation exchange capacity at the 10% biochar treatment levels (both incorporated   and top dressed).
• Small increases (<6%) in soil pH. Average soil pH in the biochar amended plots was 8.5 compared to 8.3 in the control plots.
• Leaf tissue samples have been taken but no trends have been observed to date.

The project will be monitored until 2020 and at that time we will run statistical analyses on both soil and leaf tissue analyses that we have collected over the years.

If you have any questions about the trial or would like to learn more about biochar in the Great Plains, please contact Heather Nobert of the Nebraska Forest Service at (402)-472-2941 or hnobert2@unl.edu or visit the Great Plains Biochar Initiative website here.