title: Influence of biochar amendments on the sorption-desorption of aminocyclopyrachlor, bentazone and pyraclostrobin pesticides to an agricultural soil.
abstract: The many advantageous properties of biochar have led to the recent interest in the use of this carbonaceous material as a soil amendment. However, there are limited studies dealing with the effect of biochar on the behavior of pesticides applied to crops. The objective of this work was to determine the effect of various biochars on the sorption-desorption of the herbicides aminocyclopyrachlor (6-amino-5-chloro-2-cyclopropyl-4-pyrimidinacarboxylic acid) and bentazone (3-isopropyl-1H-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide) and the fungicide pyraclostrobin (methyl 2-[1-(4-chlorophenyl) pyrazol-3-yloxymethil]-N-methoxycarbanilate) to a silt loam soil. Aminocyclopyrachlor and bentazone were almost completely sorbed by the soils amended with the biochars produced from wood pellets. However, lower sorption of the herbicides was observed in the soils amended with the biochar made from macadamia nut shells as compared to the unamended soil, which was attributed to the competition between dissolved organic carbon (DOC) from the biochar and the herbicides for sorption sites. Our results showed that pyraclostrobin is highly sorbed to soil, and the addition of biochars to soil did not further increase its sorption. Thus, addition of biochars to increase the retention of low mobility pesticides in soil appears to not be necessary. On the other hand, biochars with high surface areas and low DOC contents can increase the sorption of highly mobile pesticides in soil.
authors.affiliation: Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNASE-CSIC), Sevilla, Spain. Electronic address: macabrera@irnase.csic.es.
authors.forename: A
authors.initials: A
authors.lastname: Cabrera
authors.affiliation: Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNASE-CSIC), Sevilla, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Cox
authors.affiliation: US Department of Agriculture - Agricultural Research Service, St. Paul, MN, USA.
authors.forename: K
authors.initials: K
authors.lastname: Spokas
authors.affiliation: Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNASE-CSIC), Sevilla, Spain.
authors.forename: M C
authors.initials: MC
authors.lastname: Hermosín
authors.affiliation: Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNASE-CSIC), Sevilla, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Cornejo
authors.affiliation: US Department of Agriculture - Agricultural Research Service, St. Paul, MN, USA.
authors.forename: W C
authors.initials: WC
authors.lastname: Koskinen
mesh_terms: D000327:Adsorption; D000383:Agriculture; D001581:Benzothiadiazines / Q000032:analysis / Q000737:chemistry*; D002219:Carbamates / Q000032:analysis / Q000737:chemistry*; D002606:Charcoal / Q000737:chemistry*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D006540:Herbicides / Q000032:analysis / Q000737:chemistry*; D011720:Pyrazoles / Q000032:analysis / Q000737:chemistry*; D011743:Pyrimidines / Q000032:analysis / Q000737:chemistry*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry; D000073739:Strobilurins
chemical_list: D001581:Benzothiadiazines; D002219:Carbamates; D006540:Herbicides; D011720:Pyrazoles; D011743:Pyrimidines; D012987:Soil; D012989:Soil Pollutants; D000073739:Strobilurins; C540010:biochar; D002606:Charcoal; C513428:pyrachlostrobin; C560341:aminocyclopyrachlor; C002003:bentazone
keywords: Biochar; Fungicide; Herbicide; Organic amendment; Sorption