Biochar and Soil Health

Durham County N.C. Cooperative Extension / Soil and Environmental Microbial Ecology Group (SEMEG)

Presents:

Title: The impact of biochar on soil health in Sandhills (NC) agroecological systems:

A soil physiochemical and biological properties assessment.

Dr. Terrence G. Gardner and Dr. Juan P. Frene

Biochar may enhance soil health in sandy soils under peach-tree production. A study was initiated in the Sandhills of North Carolina by applying pine-biochar at two different rates (5% and 10% v/v%) and types of application in 2017. Soil organic matter (SOM) dynamics was assessed via soil organic C (SOC), total nitrogen (TN), active C (POXC), aggregate fractions (macro-, micro-aggregates, and clay+silt particles), and enzyme activities (C, N, P, S and, CNPS activity). Additionally, soil microbial structure was analyzed with EL-FAME and DNA sequencing analysis. This study was carried out at two depths (0-15 and 15-30 cm) and in two consecutive years after biochar addition (2018 and 2019). After the first year of pine-biochar application, POXC decreased in all biochar treatments, SOC was higher in the 10%-Inc treatment, while macroaggregates was highest in the 5%-Sur compared to the non-treated control. Soil enzymatic activities involve in C and P cycling indicated that biochar application decreased these enzymatic activities, while it has the opposite trend on enzymatic activities involves on N and S cycling as well as CNPS activity. Biochar addition changed the microbial community composition towards a more gram-positive bacteria (relative to gram-negative bacteria) dominated community, and a lesser stress of microbial community, small cy/pre ration in biochar added treatments. These changes allowed to the microbial community to grow as reflected in Total FAME and mainly in gram-positive bacteria. These results suggest early changes in SOM dynamics and biogeochemical cycling have the potential to guide producers with the long-term application of pine-biochar, and change the soil biology and therefore ecosystem functioning of the sandy soil.