title: Maize, switchgrass, and ponderosa pine biochar added to soil increased herbicide sorption and decreased herbicide efficacy.
abstract: Biochar, a by-product of pyrolysis made from a wide array of plant biomass when producing biofuels, is a proposed soil amendment to improve soil health. This study measured herbicide sorption and efficacy when soils were treated with low (1% w/w) or high (10% w/w) amounts of biochar manufactured from different feedstocks [maize (Zea mays) stover, switchgrass (Panicum vigatum), and ponderosa pine (Pinus ponderosa)], and treated with different post-processing techniques. Twenty-four hour batch equilibration measured sorption of (14)C-labelled atrazine or 2,4-D to two soil types with and without biochar amendments. Herbicide efficacy was measured with and without biochar using speed of seed germination tests of sensitive species. Biochar amended soils sorbed more herbicide than untreated soils, with major differences due to biochar application rate but minor differences due to biochar type or post-process handling technique. Biochar presence increased the speed of seed germination compared with herbicide alone addition. These data indicate that biochar addition to soil can increase herbicide sorption and reduce efficacy. Evaluation for site-specific biochar applications may be warranted to obtain maximal benefits without compromising other agronomic practices.
authors.affiliation: a Plant Science Department , South Dakota State University , Brookings , South Dakota , USA.
authors.forename: Sharon A
authors.initials: SA
authors.lastname: Clay
authors.affiliation: a Plant Science Department , South Dakota State University , Brookings , South Dakota , USA.
authors.forename: Kaitlynn K
authors.initials: KK
authors.lastname: Krack
authors.affiliation: a Plant Science Department , South Dakota State University , Brookings , South Dakota , USA.
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Bruggeman
authors.affiliation: b USDA-Agricultural Research Service, NCARL , Brookings , South Dakota , USA.
authors.forename: Sharon
authors.initials: S
authors.lastname: Papiernik
authors.affiliation: a Plant Science Department , South Dakota State University , Brookings , South Dakota , USA.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Schumacher
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid; D000327:Adsorption / Q000187:drug effects*; D001280:Atrazine; D001673:Biodegradation, Environmental; D002606:Charcoal / Q000737:chemistry*; D003120:Colorado; D052918:Environmental Restoration and Remediation; D006540:Herbicides / Q000737:chemistry*; D008897:Panicum / Q000737:chemistry*; D041604:Pinus ponderosa / Q000737:chemistry*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000737:chemistry; D003313:Zea mays / Q000737:chemistry*
chemical_list: D006540:Herbicides; D012987:Soil; D012989:Soil Pollutants; D002606:Charcoal; D015084:2,4-Dichlorophenoxyacetic Acid; D001280:Atrazine
keywords: 2,4-D; Atrazine; herbicide efficacy; sorption; speed of germination