title: Decay characteristics and erosion-related transport of glyphosate in Chinese loess soil under field conditions.
abstract: The decay characteristics and erosion-related transport of glyphosate and aminomethylphosphonic acid (AMPA) were monitored for 35 d at different slope gradients and rates of application in plots with loess soil on the Loess Plateau, China. The initial glyphosate decayed rapidly (half-life of 3.5d) in the upper 2 cm of soil following a first-order rate of decay. AMPA content in the 0-2 cm soil layer correspondingly peaked 3d after glyphosate application and then gradually decreased. The residues of glyphosate and AMPA decreased significantly with soil depth (p<0.05) independently of the slope inclination and application rate. About 0.36% of the glyphosate initially applied was transported from plots after one erosive rain 2d after the application. Glyphosate and AMPA concentrations in runoff were low while the contents in the sediment were much higher than in the upper 2 cm of the soil.
  Although the rate of glyphosate decay is rapid in Chinese loess soil, the risks of glyphosate and AMPA need to be taken into account especially in the area with highly erosive rainfall.
authors.affiliation: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, 712100 Yangling, China; Soil Physics and Land Management, Wageningen University, P.O. Box 47, 6700 AA Wageningen, The Netherlands; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: xiaomei.yang@wur.nl.
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, 712100 Yangling, China; Institute of Soil and Water Conservation, Northwest A&F University, 712100 Yangling, China. Electronic address: wafe@ms.iswc.ac.cn.
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.affiliation: Soil Physics and Land Management, Wageningen University, P.O. Box 47, 6700 AA Wageningen, The Netherlands.
authors.forename: Célia P M
authors.initials: CPM
authors.lastname: Bento
authors.affiliation: College of Geography and Environment, Baoji University of Arts and Sciences, 712300 Baoji, Shaanxi, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Meng
authors.affiliation: Institute of Food Safety (RIKILT), Wageningen University, P.O. Box 230, 6700 AE Wageningen, The Netherlands.
authors.forename: Ruud
authors.initials: R
authors.lastname: van Dam
authors.affiliation: Institute of Food Safety (RIKILT), Wageningen University, P.O. Box 230, 6700 AE Wageningen, The Netherlands.
authors.forename: Hans
authors.initials: H
authors.lastname: Mol
authors.affiliation: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, 712100 Yangling, China; Institute of Soil and Water Conservation, Northwest A&F University, 712100 Yangling, China.
authors.forename: Guobin
authors.initials: G
authors.lastname: Liu
authors.affiliation: Soil Physics and Land Management, Wageningen University, P.O. Box 47, 6700 AA Wageningen, The Netherlands.
authors.forename: Coen J
authors.initials: CJ
authors.lastname: Ritsema
authors.affiliation: Soil Physics and Land Management, Wageningen University, P.O. Box 47, 6700 AA Wageningen, The Netherlands; Institute of Crop Science and Resources Conservation (INRES), University of Bonn, 53115 Bonn, Germany.
authors.forename: Violette
authors.initials: V
authors.lastname: Geissen
keywords: Decay; Erosion; Glyphosate; Loess soil; Particulate-facilitated transport