Biochar's influence on plant growth and soil conditioning effects of native and invasive prairie plant species

Background/Question/Methods

Non-native species can alter soil properties to promote invasive plant growth, leading to the displacement of native species.  These soil-conditioning effects can persist even after non-native species have been removed.  Soil amendments, most notably carbon soil amendments, are likely to have an effect on the duration and magnitude of soil legacy effects.  Biochar is a highly stable form of black carbon produced from the pyrolysis of natural materials.  As a soil amendment, biochar can significantly increase overall soil quality and promote crop growth.  However, there has been little work done to explore biochar’s potential to restore native plant communities or its capacity to reduce the prevalence of invasive species. Soils (+/- biochar) were conditioned by growing big bluestem (Andropogon gerardi), purple prairie clover (Dalea purpurea), Johnson grass (Sorghum halepnse), or Chinese bushclover (Lespedeza cuneata) in monoculture for three months.  The plants were harvested and the conditioned soil was bulked by species. Each species was then reseeded into the conditioned soils and allowed to grow for 30 days.  At the end of the growth period, the number of branches, plant height, and root length was recorded.  Plants were separated into aboveground and root biomass, dried, and dry weight was measured.

Results/Conclusions

Preliminary results suggest both the amendment and conditioning had an effect on plant growth, most notably for Johnson grass root length, plant height, and biomass. Complete data analysis is ongoing and will be completed in March 2015.