Sorption-desorption and biodegradation of sulfometuron-methyl and its effects on the bacterial communities in Amazonian soils amended with aged biochar

Author(s)

Alvarez, Dasiel Obregon ^{[1, 2]} ; Mendes, Kassio Ferreira ^[3] ; Tosi, Micaela ^[1] ; de Souza, Leandro Fonseca ^[2] ; Campos Cedano, Johnny Carlos ^[4] ; de Souza Falcao, Newton Paulo ^[4] ; Dunfield, Kari ^[1] ; Tsai, Siu Mui ^[2] ; Tornisielo, Valdemar Luiz ^[5]

Affiliation

^[1] Univ Guelph, Sch Environm Sci, Guelph, ON N1G 2W1 - Canada

^[2] Univ Sao Paulo, Ctr Nucl Energy Agr CENA, Cell & Mol Biol Lab, Av Centenario 303, BR-13400970 Piracicaba, SP - Brazil

^[3] Univ Fed Vicosa, Dept Agron, Ave Peter Henry Rolfs S-N, BR-36570000 Vicosa, MG - Brazil

^[4] Natl Inst Amazonian Res INPA, Dept Agr Sci, Av Andre Araujo 2936, BR-69060001 Manaus, Amazonas - Brazil

^[5] Univ Sao Paulo, Ctr Nucl Energy Agr CENA, Ecotoxicol Lab, Av Centenario 303, BR-13400970 Piracicaba, SP - Brazil

• Document type: Journal article
• Source: ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY; v. 207, JAN 1 2021.
• Web of Science Citations: 2

Abstract

Sulfometuron-methyl is a broad-spectrum herbicide, used throughout Brazil; however, its environmental impacts in biochar (BC) amended soils is not fully understood. Biochar is known to enhance soil quality but can also have undesired effects such as altering the bioavailability and behavior of herbicides. Microbial communities can degrade herbicides such as sulfometuron-methyl in soils; however, they are known to be affected by BC. Therefore, it is important to understand the tripartite interaction between these factors. This research aimed to evaluate the sorption-desorption and biodegradation of sulfometuron-methyl in Amazonian soils amended with BC, and to assess the effects of the interactions between BC and sulfometuron-methyl on soil bacterial com-munities. Soil samples were collected from field plots amended with BC at three doses (0, 40 and 80 t ha(-1)) applied ten years ago. The herbicide sorption and desorption were evaluated using a batch equilibrium method. Mineralization and biodegradation studies were conducted in microcosms incubated with C-14-sulfometuronmethyl for 80 days. Systematic soil sampling, followed by DNA extraction, quantification (qPCR) and 16S rRNA amplicon sequencing were performed. The presence of BC increased the sorption of the herbicide to the soil by 11% (BC40) and 16% (BC80) compared to unamended soil. The presence of BC also affected the degradation of C-14-sulfometuron-methyl, reducing the mineralization rate and increasing the degradation half-life times (DT50) from 36.67 days in unamended soil to 52.11 and 55.45 days in BC40 and BC80 soils, respectively. The herbicide application altered the bacterial communities, affecting abundance and richness, and changing the taxonomic diversity (i.e., some taxa were promoted and other inhibited). A tripartite interaction was found between BC, the herbicide and soil bacterial communities, suggesting that it is important to consider the environmental impact of soil applied herbicides in biochar amended soils. (AU)

• FAPESP's process: 16/17683-1 - Assessing biochar and hidrochar's ability to reduce bioavailability of herbicides and metabolites in soils
• Grantee: Kassio Ferreira Mendes
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 16/24695-6 - Spatio-temporal dynamics of the active microbiota on the methane cycling in an Amazonian soil after forest-to-pasture conversion
• Grantee: Dasiel Obregón Alvarez
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)