title: Modeling fungicides mobility in undisturbed vineyard soil cores unamended and amended with spent mushroom substrates.
abstract: The performance of the pesticide fate model PRZM to predict the fate of two fungicides, penconazole and metalaxyl, and the major metabolite of metalaxyl (CGA-62826), in amended and unamended vineyard soils was tested from undisturbed soils columns experiments. Three different treatments were tested in two soils: control soil (unamended), and soil amended with fresh or composted spent mushroom substrates, which correspond to common agricultural practices in Spain. Leaching experiments were performed under non-saturated flow conditions. The model was parameterized with laboratory and literature data, and using pedotransfer functions. It was first calibrated for water flow against chloride breakthrough curves. The key parameter was the hydrodynamic dispersion coefficient (DISP). No leaching of penconazole, the most hydrophobic fungicide, was observed. It remained in the top 0-8 cm of the column. In any case, simulations were highly correlated to the experimental results. On the contrary, metalaxyl and its metabolite were consistently found in the leachates. A calibration step of the Kd of metalaxyl and CGA-62826 and of DISP for CGA-62826 was necessary to obtain good prediction of the leaching of both compounds. PRZM generally simulated acceptable metalaxyl vertical distribution in the soil profiles although results were overestimated for its metabolite. Nevertheless, PRZM can be reasonably used to assess the leaching (through breakthrough curves) and vertical distribution of fungicides in amended soils, knowing their DISP values.
authors.affiliation: Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA-CSIC), Cordel de Merinas 40-52, 37008 Salamanca, Spain. Electronic address: jmmarin1981@hotmail.com.
authors.forename: Jesús María
authors.initials: JM
authors.lastname: Marín-Benito
authors.affiliation: Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA-CSIC), Cordel de Merinas 40-52, 37008 Salamanca, Spain.
authors.forename: María Sonia
authors.initials: MS
authors.lastname: Rodríguez-Cruz
authors.affiliation: Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA-CSIC), Cordel de Merinas 40-52, 37008 Salamanca, Spain.
authors.forename: María Jesús
authors.initials: MJ
authors.lastname: Sánchez-Martín
authors.affiliation: INRA-AgroParisTech, UMR 1402 ECOSYS, Route de Saint Cyr, 78026 Versailles, France.
authors.forename: Laure
authors.initials: L
authors.lastname: Mamy
mesh_terms: D000363:Agaricales / Q000737:chemistry*; D000383:Agriculture; D005659:Fungicides, Industrial / Q000032:analysis / Q000737:chemistry*; D008962:Models, Theoretical; D009038:Motion; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis / Q000737:chemistry*; D013030:Spain; D027843:Vitis / Q000254:growth & development
chemical_list: D005659:Fungicides, Industrial; D012987:Soil; D012989:Soil Pollutants
keywords: Fungicides; Leaching; Modeling; Organic amendments; PRZM; Undisturbed soil columns