Greenhouse Study on Southern Highbush Blueberries in Soilless Media Amended with Briochar to Enhance Plant Growth and Mycorrhizal Fungi Colonization

UNCP Author/Contributor (non-UNCP co-authors, if there are any, appear on document)
Mariam Qambar (Creator)
The University of North Carolina at Pembroke (UNCP )
Web Site:
Rita Hagevick

Abstract: Amending soil with biochar, a highly porous and carbonaceous product of pyrolyzed organic material, has been found to improve blueberry growth. However, little work has been done to investigate the use of biochar as a component of soilless substrates for containerized blueberry production, a growing trend in the blueberry industry. Peat moss and perlite, two of the most commonly used components of soilless substrates, are not considered sustainable due to limited resources and high transportation costs. The purpose of this study was to determine if biochar can be a replacement for perlite and peat moss in containerized production of blueberry. A 12-week greenhouse study was conducted to evaluate the plant growth of two southern highbush blueberry cultivars (Vaccinium darrowii) ‘Jubilee’ and ‘Jewel’ in using locally sourced materials [green waste compost (C) and pine bark (Bk)] in conjunction with sphagnum peat moss (Pt), perlite (Pr), and biochar (Bi) produced from Douglas fir at 700 °C . Substrate treatments were Bk30C30Pt30Bi10, Bk30C30Pt30Pr10, Bk40C40Bi20, Bk40C40Pr10Bi10, and Bk40C40Pr20 (percentages indicated as subscripts). Across treatments, Jewel had a higher total plant dry weight than Jubilee, 10.92 and 8.69 (g/plant) respectively. When plants grown in substrates Bk30C30Pt30Bi10and Bk30C30Pt30Pr10 were on average 60% larger than plants grown in treatments without peat moss. The low pH of the peat moss (4.5) likely buffered the high pH of the compost (7.5), allowing for greater plant growth during the first half of the study. The soil solution pH of all treatments was well above the pH recommended for blueberry at the end of the study, an affect of the compost, which was a component of all substrate treatments. Soil solution analysis across weeks indicate that the biochar did not increase the pH more than the perlite, further proof that compost was the primarily driver of pH increase. The leaf nutrient analysis revealed that all plants were low in nitrogen and phosphorous, likely a result of the higher pH values. We found no effect on mycorrhizal root colonization. Overall, biochar has potential to be a suitable replacement for perlite in containerized blueberry production when paired with low pH substrate materials such as peat moss. In this study, green waste compost did not appear to be a suitable component of substrates for containerized blueberry production.

Additional Information

Language: English
Date: 2020
Perlite, Soil Amendments, Vaccinium Corymbosum, Indoor Farming, Plant Nutrition,

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