ARS | Publication request: Effect of Biochar on Bioavailability of Atrazine and Metribuzin in Two Soils

Submitted to: Weed Science Society of America Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: January 17, 2011
Publication Date: February 7, 2011
Citation: Shaner, D.L., Boydston, R.A., Krutz, L.J., Collins, H.P. 2011. Effect of Biochar on Bioavailability of Atrazine and Metribuzin in Two Soils. Weed Science Society of America Meeting Abstracts. Feb 7, 2011 Portland Oregon.

Technical Abstract: Effect of Biochar on Bioavailability of Atrazine and Metribuzin in Two Soils Biochar is a fine-grained, carbon enriched product created when biomass (e.g. wood waste, manures) is burned at relatively low temperatures and under an anoxic atmosphere. Biochar is being added to soil help retain nutrients and increase water holding capacity. Biochar may also tie up herbicides similar to activated charcoal (AC), negating the herbicide’s efficacy. In this study the effect of biochar was compared to AC on the binding and efficacy of atrazine and metribuzin in a Quincy Sand and a Warden Sandy Loam. While biochar did increase the binding of both herbicides to both soil, it was not as effective as activated charcoal. Even 22.5 thousand kg ha-1 of biochar was less effective than 224 kg ha-1 of AC. AC completely safened atrazine and metribuzin on oats in both soils at 1 kg ha-1 and 0.5 kg ha-1, respectively. Biochar at 22.5k kg ha-1 decreased the pre-emergent activity of atrazine on oats by approximately 20-and 5-fold in the sand and sandy loam soils, respectively. The pre-emergent activity of metribuzin was decreased approximately 10- and 2.5-fold at the same rate of biochar in the sand and sandy loam soil, respectively.