Biochar As a Temperate Amendment and Its Function Across a Soil Resource Gradient.

Lignocellulosic bioenergy conversion involves the pyrolization of woody and herbaceous materials to yield bio-oil, volatile gasses, and biomass-derived black carbon (biochar).Biochar has received recent attention as a potential soil amendment and has suggested benefits such as improved soil fertility, terrestrial carbon sequestration, and reductions in greenhouse gas emissions. Most biochar trials have been conducted on highly leached tropical soils and limited information is available regarding biochar impacts on temperate soils. The objectives of this study were to 1) determine the effects of biochar additions upon soil resource availability and plant growth in the southern United States and 2) assess how biochar and fertilizer additions affect competition between trees and grasses. We hypothesized that 1) biochar and fertilizer additions will increase soil resource availability in this temperate region and 2) increased soil resource availability due to these additions will decrease interspecific competition between trees and grasses. To test these hypotheses, a field-scale biochar experiment with three rates of biochar (0, 5, and 20 Mg ha^-1), two rates of fertilization (0 and 56 kg ha^-1), and three rates of competition (no competition, low competition, and high competition) was established in northeastern Mississippi in 2012. Loblolly pine and switchgrass were chosen species due to recent interest in their management in co-culture. Soil N, foliar N, soil moisture, and pine and switchgrass productivity were assessed for the 2012 and 2013 growing seasons. We will present preliminary results related to resource availability and growth response to the specified treatments.