| Title | Effects of wood amendments on the degradation of terbuthylazine and on soil microbial community activity in a clay loam soil |
| Abstract | The herbicide terbuthylazine is widely used within the EU; however, its frequent detection in surface and groundwater, together with its intrinsic toxicological properties, may pose a risk both for human and environmental health. Organic amendments have recently been proposed as a possible herbicide sorbent in soil, in order to limit herbicide movement from soil to water. The environmental fate of terbuthylazine depends not only in its mobility but also in its persistence. The latter is directly dependent on microbial degradation. For this reason, the effects of pine and oak residues on terbuthylazine soil microbial community functioning and on the potential of this community for terbuthylazine degradation were studied. For this purpose, degradation kinetics, soil dehydrogenase activity and the number of live bacteria were assessed in a clay loam soil treated with terbuthylazine and either amended with pine or oak wood or unamended (sterilised and non-sterilised). At day 65, 85%of the herbicide applied still persisted in the sterile soil, 73 % in the pine-amended one and 63 % in the oak-amended and unamended ones. Pine residues increased the sorption of terbuthylazine to soil and hampered microbial degradation owing to its high terbuthylazine sorption capacity and a decrease in the bioavailability of the herbicide. On the contrary, in the presence of oak residues, the herbicide sorption did not increase significantly. The overall results confirm the active role of the soil microbial community in terbuthylazine degradation in amended and unamended soils and in a liquid enrichment culture performed using an aliquot of the same soil as the inoculum. In this clay loam soil, in the absence of amendments, the herbicide was found to be quite persistent (t1/2>95 days), while in the enrichment culture, the same natural soil bacterial community was able to halve terbuthylazine in 24 days. The high terbuthylazine persistence in this soil was presumably ascribable to its texture and in particular to the mineralogy of the clay fraction. |
| Source | Water, air and soil pollution (Print) 223 (8), pp. 5401–5412 |
| Keywords | TerbuthylazineDegradationSoil textureOrganic amendmentsPine and oak residuesMicrobial community activity |
| Journal | Water, air and soil pollution (Print) |
| Editor | Kluwer Academic Publishers, Dordrecht, Paesi Bassi |
| Year | 2012 |
| Type | Articolo in rivista |
| DOI | 10.1007/s11270-012-1289-z |
| Authors | Grenni, Paola; Rodríguez-Cruz, M. Sonia; Herrero-Hernández, Eliseo; Marín-Benito, Jesús M.; Sánchez-Martín, Maria J.; Barra Caracciolo, Anna |
| Text | 191696 2012 10.1007/s11270 012 1289 z Scopus 2 s2.0 84867334813 Terbuthylazine Degradation Soil texture Organic amendments Pine and oak residues Microbial community activity Effects of wood amendments on the degradation of terbuthylazine and on soil microbial community activity in a clay loam soil Grenni, Paola; Rodriguez Cruz, M. Sonia; Herrero Hernandez, Eliseo; Marin Benito, Jesus M.; Sanchez Martin, Maria J.; Barra Caracciolo, Anna Consiglio Nazionale delle Ricerche; CSIC Instituto de Recursos Naturales y Agrobiologia de Salamanca IRNASA The herbicide terbuthylazine is widely used within the EU; however, its frequent detection in surface and groundwater, together with its intrinsic toxicological properties, may pose a risk both for human and environmental health. Organic amendments have recently been proposed as a possible herbicide sorbent in soil, in order to limit herbicide movement from soil to water. The environmental fate of terbuthylazine depends not only in its mobility but also in its persistence. The latter is directly dependent on microbial degradation. For this reason, the effects of pine and oak residues on terbuthylazine soil microbial community functioning and on the potential of this community for terbuthylazine degradation were studied. For this purpose, degradation kinetics, soil dehydrogenase activity and the number of live bacteria were assessed in a clay loam soil treated with terbuthylazine and either amended with pine or oak wood or unamended sterilised and non sterilised . At day 65, 85%of the herbicide applied still persisted in the sterile soil, 73 % in the pine amended one and 63 % in the oak amended and unamended ones. Pine residues increased the sorption of terbuthylazine to soil and hampered microbial degradation owing to its high terbuthylazine sorption capacity and a decrease in the bioavailability of the herbicide. On the contrary, in the presence of oak residues, the herbicide sorption did not increase significantly. The overall results confirm the active role of the soil microbial community in terbuthylazine degradation in amended and unamended soils and in a liquid enrichment culture performed using an aliquot of the same soil as the inoculum. In this clay loam soil, in the absence of amendments, the herbicide was found to be quite persistent t1/2>95 days , while in the enrichment culture, the same natural soil bacterial community was able to halve terbuthylazine in 24 days. The high terbuthylazine persistence in this soil was presumably ascribable to its texture and in particular to the mineralogy of the clay fraction. 223 Published version http //www.scopus.com/record/display.url eid=2 s2.0 84867334813 origin=inward 25/07/2012 Terbuthylazine,Effects of Wood Amendments on the Degradation of Terbuthylazine and on Soil Microbial Community Activity in a Clay Loam Soil Articolo pubblicato Effects_of_Wood_Amendments_on_the_Degradation_of_Terbuthylazine_and_on_Soil_Microbial_Community_Activity_in_a_Clay_Loam_Soil.pdf Articolo in rivista Kluwer Academic Publishers 0049 6979 Water, air and soil pollution Print Water, air and soil pollution Print Water, air and soil pollution. Print Water air soil pollut. Print Water, air soil pollution Print anna.barracaracciolo BARRA CARACCIOLO ANNA paola.grenni GRENNI PAOLA TA.P04.005.011 Vulnerabilita degli ecosistemi delle acque sotterranee e attenuazione naturale degli inquinanti nel suolo e nel sottosuolo |
