Optimizing Eastern Red Cedar Biochar for Geranium and Petunia Production

Researchers at Oklahoma State University and the University of Florida found that Eastern red cedar biochar, particularly at 15% of the media mix and at higher temperatures (500-550°C), improves growth and water use efficiency in geraniums and petunias, offering a sustainable alternative to peat moss.

May 23, 2024

2–3 minutes

Lamichhane, et al (2024) Determining Eastern Red Cedar BiocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More Soilless-Media Supplementation Rates for Potted Geranium and Petunia Production. *Horticulturae*. https://doi.org/10.3390/horticulturae10050467

A recent study conducted by researchers at Oklahoma State University and the University of Florida evaluated the use of Eastern red cedar (ERC) biochar as a soilless-media supplement for potted geranium (Pelargonium graveolens L.) and petunia (Petunia sp. J.) production in greenhouses. The research aimed to determine optimal biochar supplementation rates and temperatures to maximize plant growth and performance. The researchers produced biochar from ERC biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More at three temperature ranges: 300-350°C, 400-450°C, and 500-550°C. They then mixed the biochar into a soilless media at various volume ratios: 15%, 30%, 45%, and 60%. For comparison, ERC bark was also added to the media at the same ratios. The study measured physical properties of the media, plant growth characteristics, and nutrient content in both the media and the plants.

The findings revealed that biochar improved media properties such as total porosityPorosity of biochar is a key factor in its effectiveness as a soil amendment and its ability to retain water and nutrients. Biochar’s porosity is influenced by feedstock type and pyrolysis temperature, and it plays a crucial role in microbial activity and overall soil health. Biochar More and water holding capacityWater holding capacity is the amount of water that soil can retain. Biochar can significantly increase the water holding capacity of soil, improving its ability to withstand drought conditions and support plant growth. More (WHC). Notably, the 60% biochar mix at 400-450°C had the highest total porosity, while the greatest WHC was observed with a 30% biochar mix at 400-450°C. For geranium growth, height, water use efficiency, and shoot dry weight were highest with 15% biochar at 500-550°C. The greatest number of flowers was produced with 45% biochar at 500-550°C. For petunia growth, height was greatest with 15% biochar at 300-350°C. Shoot dry weight and water use efficiency were highest with 15% biochar at 500-550°C. However, the greatest number of flowers and flower diameter were achieved with 100% soilless media.

The study concluded that biochar supplementation, particularly at 15% of the media mix, significantly benefits the growth and development of both geraniums and petunias, with higher temperatures (500-550°C) proving most effective. However, for optimal flowering, 100% soilless media was best for petunias. This research supports the potential of ERC biochar as a sustainable alternative to peat moss in soilless media, offering environmental benefits and promoting plant growth in greenhouse production.

This study highlights the potential of using biochar as a sustainable horticultural practice, which could help reduce reliance on peat moss and support environmental conservation efforts. Further research could expand on these findings to optimize biochar use across different plant species and growing conditions.