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ARS Home » Southeast Area » Auburn, Alabama » Soil Dynamics Research » Research » Publications at this Location » Publication #419103
Research Project: Sustaining Productivity and Ecosystem Services of Agricultural and Horticultural Systems in the Southeastern United States

Location: Soil Dynamics Research

Title: Influence of biochar-herbicide interactions on weed control efficacy in sandy soil in Alabama

Author
item PUROHIT, NISITH - Auburn University
item GHOSH, RAKESH - Auburn University
item FENG, YUCHENG - Auburn University
item Prior, Stephen - Steve
item MAITY, ANIRUDDHA - Auburn University

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/13/2024
Publication Date: 9/23/2024
Citation: Purohit, N.N., Ghosh, R.K., Feng, Y., Prior, S.A., Maity, A. 2024. Influence of biochar-herbicide interactions on weed control efficacy in sandy soil in Alabama [abstract]. International Soil and Tillage Research Organization (ISTRO), 23-27 September 2024, Virginia Beach, VA.

Interpretive Summary:

Technical Abstract: Biochar, a carbon-rich byproduct of pyrolysis, has shown potential to alter pesticide efficacy depending on its physicochemical interactions with soil, microbes, and pesticides. A greenhouse study aimed to evaluate the weed control efficacy (WCE) in biochar-applied sandy soil in response to herbicide on two weed species: Eleusine indica (Goose grass) and Ipomoea lacunosa (pitted morning glory). The experiment was designed as a randomized block with two factors: biochar type and herbicide. We examined the effects of four biochar types (sugarcane, wood, coconut, and pinewood) on the efficacy of two commonly used preemergence herbicides in Alabama row crops, proxasulfone and clomazone. Biochar was applied at 2t/ha, and herbicides were used at recommended field doses. Biochar applied trays with herbicide (treated tray) had a higher survival rate and above-ground biomass of morning glory as compared to control (herbicide application without biochar). Bleaching of pitted morning glory was observed in all clomazone-treated trays; however, as time progressed, treated trays recovered from the bleaching quickly as compared to the control, suggesting enhanced adsorption of clomazone by the biochar. However, the goose grass control efficacy did not change with application of biochar, with no germination observed in pyroxasulfone-treated trays and complete bleaching in clomazone-treated trays. Biomass production across the different treatment trays significantly differed and was more pronounced in the case of pyroxasulfone than clomazone. The combination of the chemical properties and the mode of action likely governed the extent of biochar-induced reduction in bioavailability of herbicides. Sugarcane biochar demonstrated the greatest reduction in herbicide bioavailability, as indicated by the higher biomass of morning glory in these trays. Although causal mechanisms are under investigation, this work clearly demonstrates decreased efficacy of herbicides in biochar amended soils. Therefore, understanding herbicide-biochar interactions will be critical for developing sustainable weed management strategies in biochar-amended agricultural systems.