Biochar Resilience to Weathering in Northern Appalachian US Marginal Soils.

The use of biochar derived from biofuels has been shown to increase available moisture contents of soils and thus lessen decreases in water availability due to climate change. We assessed how switchgrass derived biochar weathered in 4 contrasting soils typical of the US Appalachians. Soils were representative of marginal landscapes where biofuels would not compete with agricultural crops and were typical acidic, sandy, or wet. Biochar was added to soils (1% mixture) in-situ and weathered in place for 3 years. Soils were sampled, gently washed of char fragments and char fragments were mounted on SEM billets. Unweathered char fragments (not put in the field were also examined. Billets were gold coated and viewed via scanning electron microscopy. A total of 30 samples across four replicates were examined. Biochar fragments from the field exhibited no significant differences in morphology metrics (area, perimeter, length, roundness/sphericity). Biochar fragment size was significantly different and was likely a result of field incorporation. Results suggest biochar applications in similar environments will result in minimal degradation of biochar in a similar timeframe, and that biochar benefits will persist during this period.