Biochar as a media amendment in container plant production of viola and daylily: Greenhouse gas emissions, plant growth, and N leachate.

Abstract 

In two separate experiments, this study investigated the effects of increasing amounts of biochar to standard nursery and greenhouse substrates on greenhouse gas emissions (CO2, CH4, and N2O), plant growth, and N loss via leachate. 

Experiment 1: A peat-based greenhouse substrate was amended with biochar in the production of viola (Viola cornuta L. ‘Sorbett XP Deep Orange’). Experiment 2: A bark-based nursery substrate was amended with biochar in the production of daylily (Hemerocallis x ‘EveryDaylily Cream PBR’ L.). 

Findings: In general, biochar use decreased N2O and CO2 fluxes in daylily, suggesting biochar may be beneficial in mitigating portions of global climate change as contributed by container plant production. While biochar seemed to inhibit top shoot growth in daylily, little effect was observed for top shoot viola growth. In fact, higher levels of biochar improved root dry weight in viola. Additionally, greater effects on N loss reduction were observed in treatments with higher levels of incorporated biochar for both experiments. 

Going Forward: Results suggested that future studies should focus on testing a lower range of rates of biochar, along with varied application methods, to measure growth and environmental impacts. Additionally, the improved N use efficiency observed in these trials highlight the importance of better understanding of N management and developing biochar practices in container plant production that increase N retention.

Anna-Marie Murphy, Steve Prior, Brett Runion, Heath Hoffman, Mark Johnson, and Allen Torbert