Enzyme activities and diuron persistence in soil amended with vermicompost derived from spent grape marc and treated with urea Romero Taboada, Esperanza Fernández Bayo, Jesús Dionisio Castillo Díaz, Jean Manuel Nogales, Rogelio Pesticides Vermicompost Enzymatic activity This study was supported by the Comisión Interministerial de Ciencia y Tecnología (CICYT) through project CTM2006-12214. Jesús Fernández-Bayo and Jean Manuel Castillo Diaz wish to thank the Science and Education Ministry for their FPI doctoral grants. The authors would also like to thank Amparo Salido for her technical assistance and Michael O‘Shea for proof-reading the English manuscript. Mineral fertilizers, organic amendments, and pesticides are inputs commonly used in conventional farming practices. The aim of this study was to evaluate the effects of single or combined applications of spent grape marc-vermicompost, urea, and/or diuron on soil-enzyme activities and the persistence of this herbicide in soils with low organic carbon content. The application of vermicompost enhanced dehydrogenase (DHase) enzyme activity over time but altered soil urease activity to a very limited extent. The reduction in diuron concentrations and the increase in DHase activity indicated that the soil microorganisms were capable of degrading the ureic herbicide. Treatment with vermicompost and diuron had a stimulatory effect on soil microbial activity. On the whole, the application of diuron and urea to the vermicompost-amended soil raised DHase and urease activity to maximum levels (>3 μg INTF g−1 h−1 and >47 μg NH4+ g−1 h−1, respectively). The application of urea to the unamended and vermicompost-amended soil decreased diuron persistence from 18.8 and 33 d to 12.5 and 15 d, respectively. Our findings show that although vermicompost additions reduce diuron availability, this boosts diuron degradation when combined with urea. These additions, under different soil management conditions, minimize the bioavailability and persistence of diuron and consequently the risk of leaching and seepage into aquifers. Compared with untreated soils, these types of treated soils could also improve agricultural sustainability and the quality of the environment. 2026-02-04T11:47:45Z 2026-02-04T11:47:45Z 2010-03-01 journal article Romero E., Fernández-Bayo J., Castillo Díaz J.M., Nogales R. (2010). Enzyme activities and diuron persistence in soil amended with vermicompost derived from spent grape marc and treated with urea. Applied Soil Ecology 44, 198-204. https://doi.org/10.1016/j.apsoil.2009.12.006 0929-1393 https://hdl.handle.net/10481/110654 10.1016/j.apsoil.2009.12.006 eng http://creativecommons.org/licenses/by-nc-nd/3.0/ embargoed access Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License Elsevier