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Effects of biochar blends on microbial community composition in two coastal plain soils
Citation:
Ducey, T., J. Novak, AND M. Johnson. Effects of biochar blends on microbial community composition in two coastal plain soils. Agriculture. MDPI, Basel, Switzerland, 5(4):1060-1075, (2015).
Impact/Purpose:
Biochar is a charcoal-like byproduct of pyrolysis, a biofuels technique used to extract energy from biomass. The amendment of soil with biochar has been demonstrated to have an effect not only on soil physicochemical properties, but also on soil microbial community composition and activity. A significant portion of the soils in the southeastern coastal plain are severely degraded, and therefore candidates for biochar amendment to strengthen soil health and quality. In this study two representative coastal plain soils were amended (2% by weight) with biochar made from pine chips (PC), poultry litter (PL) or with mixtures of biochar made from PC and PL (50% PC:50% PL and 80% PC:20% PL). Soil was analyzed following biochar amendment and incubation for bioavailable nutrients and microbial community composition. Our results demonstrated significant shifts in microbial community composition in response to biochar amendment, the effects of which were greatest for the pure PL biochar, which had the greatest nutrient content. Strong relationships between microbial community composition and improved soil nutrient status due to the biochar were observed. The results of this research will have widespread utility domestically and internationally as biochar is becoming widely used as a soil amendment. Incorporating the results of this research will improve soil quality and agricultural productivity while being protective of valuable water resources especially in coarse-textured, degraded soils like those found in the southeastern coastal plain.
Description:
The amendment of soil with biochar has been demonstrated to have an effect not only on the soil physicochemical properties, but also on soil microbial community composition and activity. Previous reports have demonstrated significant impacts on soil microbial community structure. These impacts are modulated not only by the biochar composition, but also on the soils physicochemical characteristics. This indicates that soil characteristics must be strongly considered prior to biochar amendment. The significant portion of the soils of the southeastern coastal plain are severely degraded, and therefore candidates for biochar amendment to strengthen soil fertility. In this study we focused on two common soil series in the southeastern coastal plain, utilizing feedstocks endemic to the area. We chose feedstocks in four ratios (100% pine chip; 80:20 mixture of pine chip to poultry litter; 50:50 mixture of pine chip to poultry litter; 100% poultry litter) prior to pyrolysis and soil amendment as a biochar product. Soil was analyzed for bioavailable nutrients via Mehlich-1 extractions, as well as microbial community composition using phospholipid fatty acid analysis (PLFA). Our results demonstrated significant shifts in microbial community composition in response to biochar amendment, the effects of which were greatest with 100% poultry litter biochar. Strong relationships between PLFAs and several Mehlich-1 extractable nutrients (Al, Cu, Fe, and P) were observed.
