Suchergebnisse

Currently used pesticides' occurrence in soils: recent results and advances in soil-monitoring and survey studies -- An Overview of Recent Research on the Role of Dissolved Organic Matter on the Environmental Fate of Pesticides in Soils -- Assessing the effects of pesticides on the soil microbial community: advances, standardization of methods and the need for a new regulatory framework -- Environmental Fate of Chiral Pesticides in Soils -- Sorption/desorption, leaching and transport behavior of pesticides in soils: A review on recent advances and published scientific research -- Plant uptake of pesticide residues from agricultural soils -- Contribution of land runoff to the release of pesticides into water bodies in arable areas -- Pesticide fate in soils under different agricultural management practices -- Biopurification systems: current advances and future prospects of on-farm biodegradation of pesticides -- Abiotic and biological technologies for the remediation of phenylurea herbicides in soils -- Bioremediation of soil ecosystems from triazine herbicides.

11 páginas, 5 figuras, 2 tablas ; Organic wastes applied as composted amendments may improve the quality of degraded soils and modify the fate of pesticides. This work has set out to study the dissipation kinetics of the herbicides chlorotoluron and flufenacet during their second-year application in field experimental plots with a sandy-loam agricultural soil without amendment (S) and amended with spent mushroom substrate (S + SMS) or green compost (S + GC). The SMS and GC were applied to the soil during the previous winter's wheat crop campaign (1 year before the second herbicide application) at rates of 140 and 85 t ha−1 (dry weight basis), respectively. The experiment involved randomized complete blocks with plots of 81 m2, including three replicates per soil treatment. Surface soils were sampled after herbicide application for 225 days, and herbicide residues in the soil samples were determined by HPLC-MS. The dissipation curves of both herbicides for the three soil treatments were better fitted to the first order multi-compartment (FOMC) kinetic model. The dissipation rates of the most hydrophobic herbicide, flufenacet, were slower than those for chlorotoluron in both unamended and amended soils. The half-life (DT50) values ranged between 20.7 to 41.1 days for chlorotoluron, and 42.9 to 75.6 days for flufenacet, and they followed the order S > S + SMS > S + GC. The DT50 values of chlorotoluron were close for S + SMS and S + GC, and the DT50 of flufenacet for S was similar to that for S + SMS. These DT50 values decreased up to four times with respect to those calculated after the first application indicating an accelerated dissipation of the herbicides after the second application especially in amended soil in comparison with unamended soil. The persistence of chlorotoluron and flufenacet in an agricultural soil was modified by the effect of the organic amendments, weather conditions, and possibly the repeated application of the compounds under real field conditions ; This research was funded by MINECO/FEDER EU, Project AGL2015-69485-R, and MCIU/AEI/FEDER EU, Project RTI2018-101587-J-I00. J.M.M.-B. thanks MINECO for his Juan de la Cierva-Incorporación (IJCI-2014-19538) contract. M.J.C. thanks for her predoctoral contract co-funded by European Social Fund (ESF) and the Consejería de Educación (Junta de Castilla y León Government). ; Peer reviewed

28 páginas, 3 tablas, 1 figura ; The management of large volumes of organic residues generated in different livestock, urban, agricultural and industrial activities is a topic of environmental and social interest. The high organic matter content of these residues means that their application as soil organic amendments in agriculture is considered one of the more sustainable options, as it could solve the problem of the accumulation of uncontrolled wastes while improving soil quality and avoiding its irreversible degradation. However, the behavior of pesticides applied to increase crop yields could be modified in the presence of these amendments in the soil. This review article addresses how the adsorption–desorption, dissipation and leaching of pesticides in soils is affected by different organic residues usually applied as organic amendments. Based on the results reported from laboratory studies, the influence on these processes has been evaluated of multiple factors related to organic residues (e.g., origin, nature, composition, rates, and incubation time of the amended soils), pesticides (e.g., with different use, structure, characteristics, and application method), and soils with different physicochemical properties. Future perspectives on this topic are also included for highlighting the need to extend these laboratory studies to field and modelling scale to better assess and predict pesticide fate in amended soil scenarios. ; This research was funded by MCIU/AEI/FEDER UE, Project "RTI2018-101587-J-I00". M.J. Carpio thanks for her predoctoral contract co-funded by European Social Fund (ESF) and the Consejería de Educación (Junta de Castilla y León Government). ; Peer reviewed

46 páginas, 5 figuras, 3 tablas, 4 tablas suplementarias. -- The final version is available at http://www.elsevier.com ; The spread of organic pollutants from soil to other environments is one important source of environmental pollution. The addition of organic amendments to soil is an interesting strategy to control pollutants leaching. However, the contribution of different carbon types of organic amendments to organic pollutants adsorption is not clear. Hence, the objective of this work was to determine the role of carbon types of organic amendments into the adsorption of four herbicides. To this extent, organic amendments were characterized by elemental analysis and 13C-NMR and adsorption–desorption isotherms of herbicides by the organic amendments and two soils amended with them were obtained. Adsorption coefficients were correlated with the organic carbon content of the organic amendments and the adsorption process was enhanced by the hydrophobicity of herbicides and the aliphatic and aromatic carbon of amendments. Organic amendments increased the adsorption of herbicides by soils but it is not possible to extrapolate results from one soil to another because organo-mineral interactions between soils and organic amendments can modify this process. Desorption isotherms of herbicides from organic amendments and/or amended soils presented hysteresis indicating the irreversible adsorption of herbicides. Desorption results indicated, the abundance of O-alkyl and N-alkyl groups in organic amendments enhanced the hysteresis in amended soils ; This work was funded by the Spanish Ministry of Economy and Competitiveness (MINECO/FEDER) and the Regional government, Junta de Castilla y Leon as part of the projects AGL2015-69485-R and CSI240U14. ; Peer reviewed

29 páginas, 3 figuras, 2 tablas. -- Además del siguiente material suplementario: 6 páginas, 1 figura, 4 tablas. -- The definitive version is available at http://www.elsevier.com ; Lignocellulosic wastes and by-products containing lignin are now available in large amounts from forestry and industrial activities, and could be promising organic materials for the biosorption of pesticides by soils in order to reduce point-source pollution. Adding these materials to soil requires understanding the process of pesticide sorption-desorption by wood-soils, as sorption capacity could increase, with changes in pesticide bioavailability and final fate. The objective of this work was to study the effect that pine and oak wood added to soils had on the sorption/desorption of the pesticides linuron, alachlor, and metalaxyl. Experiments were conducted with two sandy loam and sandy clay soils each amended with two wood doses (5% and 50%) after different incubation times (0, 5 and 12 months). A low wood dose (5%) had no significant impact on the sorption (Kf) of alachlor, but Kf increased for linuron (up to 5.4–1.7 times) and metalaxyl (up to 4.4 and 8.6 times) in all wood-soil systems. The results were not significantly different after different incubation times. The desorption results indicated that wood decreases the sorption irreversibility of alachlor, and increases that of linuron and metalaxyl, with a varying effect of the wood-soil incubation time. The addition of a high wood dose to soil (50%) was more significant for increasing the sorption of all the pesticides, and the sorbed amounts remaining after desorption (>49% for linuron, >33% for alachlor and >6% for metalaxyl), although there was no apparent discrimination between the two types of woods. The role of the nature of the organic carbón (Koc values) for sorption was evidenced for alachlor and metalaxyl, but not for linuron. These outcomes are of interest for extending wood application to soil as a barrier for avoiding environmental risk by point-source pollution due to the use and management of pesticides in farming systems. ; This work was financially supported by the Spanish Ministry of Education and Science and the regional government, the Junta de Castilla y Leon as part of projects CTM2004-00381/TECNO and CSI02A06. ; Peer reviewed

5 páginas, 3 figuras ; The objective of this workwas to study the influence pine or oak wood added to soil as an amendment (5% w/w) had on the degradation rate of two pesticides, alachlor and metalaxyl, with different hydrophobic character. The formation of pesticide metabolites and the soil dehydrogenase activity in non-amended and amended soil samples were also monitored. The degradation of metalaxyl followed first-order kinetics, while the degradation of alachlor followed first-order or biphasic kinetics in the soil samples studied. The results indicated that the degradation rate was slower for metalaxyl than for alachlor, and for both pesticides followed the order: pine amended soil < oak amended soil < non-amended soil. The faster degradation rate in non-amended soilwas attributed to the higher sorption of pesticides by wood amended soils. The alachlor ethane sulfonic acid (ESA), and two metalaxyl metabolites (2-[(2,6-dimethylphenyl)-methoxyacetylamino]-propionic acid and N-(2,6-dimethylphenyl)-2-methoxy-acetamide) were detected during the incubation period. Soil dehydrogenase activity recorded close values in non-amended and amended soil treated with alachlor, but it was higher in wood amended soil treated with metalaxyl. Pine and oak wood increase the immobilization of the pesticides studied, but they also limit their bioavailability in soil by decreasing their degradation rate in amended soil. ; This work was financially supported by the Spanish Ministry of Education and Science and the regional government, the Junta de Castilla-Leon as part of projects CTM2004-00381/TECNO and CSI02A06. ; Peer reviewed

49 páginas, 5 figuras, 3 tablas suplementarias. -- The final version is available at http://www.elsevier.com ; This paper reports the mobility and total balance of chlorotoluron (CTL), flufenacet (FNC) and bromide ion (Br−) throughout a sandy soil profile after the application of spent mushroom substrate (SMS) and green compost (GC). Obtaining mobility dataset is crucial to simulate the herbicides' fate under amended soil scenarios by application pesticide leaching models with regulatory application (FOCUS models). The application of organic residues is nowadays increased to improve the crop yields and there is a gap in the simulations of this kind of amended scenarios. A two-year field experiment involving unamended soil (S) and SMS- or GC-amended soil plots was conducted. CTL, FNC, and Br− were annually applied and their residual concentrations were determined in soil profiles (0–100 cm) regularly sampled. In all the treatments the order of mobility is followed as FNC < CTL < Br−. SMS and GC increased herbicide retention in the top 10 cm by the higher organic carbon (OC) content than the unamended soil, and their ability to increase the soil's water-holding capacity and to decrease water percolation. Simultaneously dissolved organic carbon (DOC) content facilitated herbicide transport being it favoured by the initial soil moisture content and the rainfall shortly after the chemicals' initial application. Over the first year, residual amounts (<2.6%) of Br−, CTL and FNC were leached down to 90–100 cm depth in the three treatments. However, over the second year low CTL and FNC amounts (<1.0%) reached the bottom layer only in S + SMS although high Br− concentrations did so in the three treatments (<20%). According to the total balance of Br−, CTL, and FNC in the soil profiles other processes (degradation, mineralisation, bound residues formation, and/or crop uptake) different from leaching below 1 m depth might play a key role in their dissipation especially in the amended soil profiles. SMS and GC are likely to be used as organic amendments to preserve the soil and water quality but in the case of SMS, its higher DOC content could imply a higher potential risk for groundwater contamination than GC. ; This work has been funded by MINECO/FEDER UE (Project AGL2015-69485-R) and MCIU/AEI/FEDER,UE (Project RTI2018-101587-J-I00). M. J. Carpio thanks for her 28 predoctoral contract co-funded by European Social Fund (ESF) and the Consejería de Educación (Junta de Castilla y León Government). C. García-Delgado and J.M. Marín Benito thank MINECO for their respective Juan de la Cierva-Formación (JCFI-2015-23543) and Juan de la Cierva-Incorporación (IJCI-2014-19538) contracts. ; Peer reviewed

36 páginas, 3 tablas y 4 figuras . -- The final version is available at http://www.elsevier.com ; Soil is a non-renewable resource, and its degradation compromises human health, 2 natural ecosystems, and even the climate. The application of organic amendments and 3 herbicides is commonplace in agriculture, and their impact on soil fertility needs to be 4 evaluated. Therefore, the objective was to evaluate the effect on soil microbial activity 5 and structure of amendments, sewage sludge (SS) and green compost (GC), and the rate 6 of herbicide pethoxamid applied (2, 10 and 50 mg kg-1). Herbicide dissipation kinetics, 7 soil dehydrogenase activity (DHA) and the profile of phospholipid-derived fatty acids 8 (PLFAs) extracted from the soil have been determined in unamended (S) and amended 9 (S+SS and S+GC) soils. The dissipation curves of pethoxamid applied at the three rates 10 closely fitted a single first order kinetics model in all the soils. The dissipation rate 11 decreased with the rate applied in the order 2 mg kg-1 > 10 mg kg-1 > 50 mg kg-1 in 12 unamended and amended soils. However, the half-life or time required for 50% 13 dissipation (DT50) of pethoxamid was not significantly different in unamended and 14 amended soils when applied at 2 and 10 mg kg-1, but it was lower in the amended soils 15 than in the unamended one when the herbicide was applied at the highest rate. The 16 highest DHA mean values were obtained in S+GC treated with pethoxamid at 2, 10 and 17 50 mg kg-1; however, DHA was lower in S+SS than in S. Peak DHA values were 18 observed in S and S+GC soils treated with pethoxamid at 2 mg kg-1 at 15 days of 19 incubation, and in S, S+GC and S+SS treated with the herbicide at 10 and 50 mg kg-1 at 20 35 days of incubation. These peak DHA values are close to 50% of herbicide 21 dissipation. A statistical analysis of the PLFA results has revealed significant effects for 22 sampling time in all the soils, for the pethoxamid rate, and for the interaction between 23 time and pethoxamid rate only in S+GC and S+SS. The application of organic 24 amendments to soil accelerated the dissipation of higher rates of pethoxamid compared to the unamended soil, which is important to prevent the herbicide's negative impacts 26 on the soil microbial community. ; This work was supported by the regional government, the "Junta de Castilla y León" 456 (project CSI264A12-1). Eva Pose-Juan and Jesús M. Marín-Benito were supported by a 457 postdoctoral contract (Juan de la Cierva JCI-2011-10150 and IJCI-2014-19538, 458 respectively) from the Spanish Ministry of Economy and Competitiveness. ; Peer reviewed

48 páginas, 3 tablas y 5 figuras. -- The final version is available at http://www.elsevier.com ; In the last twenty years, pesticide use in Chile has increased more than 160%, generating a greater risk of water resources pollution. The objective of this study was to assess the presence of 22 pesticides and 12 degradation products in surface water samples from the Cachapoal River basin, Central Chile, an area characterized by intense agricultural activity. Pesticide concentrations in the dissolved phase (DP) and particulate phase (PP) in samples collected in the dry season and after precipitation events was assessed. The solid-phase extraction technique was used to preconcentrate the samples and GC/MS and LC/MS were used to detect pesticides. The results present spatio-temporal variations in the proportion and concentration of pesticides and their degradation products in both the DP and PP for each site and sampling period. The most ubiquitous compounds in the dissolved phase were atrazine, atrazine-2-hydroxy (HA), cyprodinil, pyrimethanil, and tebuconazole, while in the particulate phase HA, imidacloprid, diazinon and pyrimidinol were detected. The results presented in this study make up the first record of pesticides in the dissolved and particulate phases in surface water in Chile. They show that the problem of pesticide contamination undoubtedly affects the quality of bodies of water in agricultural areas in Chile and support the need for a proper assessment of the water quality of the Cachapoal River in the future. ; This work was partly funded by the Government of Spain (MINECO/FEDER UE) as part of Project AGL2015-69485-R and National Commission for Scientific and Technological Research, Chile as part of Project CRHIAM/CONICYT/FONDAP/15130015. María José Climent thanks both the National Commission for Scientific and Technological Research (CONICYT N° 21150573) and Water Research Center for Agriculture and Mining for the financing used to carry out this work. ; Peer reviewed

9 paginas, 5 tablas, 4 figuras. ; In areas with agricultural activity, the excessive use of pesticides can contaminate water resources. That is why a multi-residue method based on solid-phase extraction (SPE) and gas chromatography analysis coupled to mass spectrometry (GS-MS) was used to determine eleven pesticides and five degradation products in surface water of Central Chile. The parameters that can affect the efficiency of the SPE process were optimized considering the information available in bibliography. As in other studies, the best results were obtained when 500 mL of water was pre-concentrated using Oasis HLB polymer cartridges and acetone and acetonitrile were used as solvents for the elution. To ensure good quantification, matrix-matched standards were used, providing good linearity in the studied concentration range (0.10-1.5 μg L-1), with recovery percentages > 60%, precisions 87% of the pesticides analyzed in this research were detected in more than one sampled site in both seasons. The most ubiquitous compounds were desethylterbuthylazine (DET), pyrimethanil, cyprodinil and diazinon, and the compounds detected in highest concentration were simazine and degradation products derived from triazines. Las Cabras and Tahuilla irrigation canals presented the highest concentrations of pesticides. Significant differences were found in the total concentration of pesticides for sites sampled at the end of the summer and winter season ; This work was partly funded by the Government of Spain (MINECO/ FEDER UE) as part of Project AGL2015-69485-R. ; Peer reviewed

25 páginas, 4 figuras, 4 tablas. -- The definitive version is avalaible at http://www.elsevier.com ; A multi-residual analytical method based on solid phase extraction (SPE) followed by liquid chromatography–electrospray ionisation–mass spectrometry (LC–MS) was developed to monitor pesticides in natural waters. Fifty-eight compounds, including herbicides, fungicides, insecticides and some of their degradation products, were surveyed to evaluate the quality of natural waters throughout the winegrowing region of La Rioja (Rioja DOCa). Ninety-two sampling points were selected, including surface and ground waters that could be affected by agricultural activities covering the region's three sub-areas. Different parameters that may affect the efficiency of the SPE procedure were optimised (sorbent type, elution solvent and sample volume), and matrix-matched standards were used to eliminate the variable matrix effect and ensure good quantification. The developed method allows the determination of target compounds below the level established by the European Union for waters for human use with suitable precision (relative standard deviations lower than 18%) and accuracy (with recoveries over 61%). Forty compounds included in this study (six insecticides, 12 herbicides, 16 fungicides and six degradation products) were detected in one or more samples. The herbicides terbuthylazine, its metabolite desethyl terbuthylazine, fluometuron and ethofumesate and the fungicides pyrimethanil and tebuconazole were the compounds most frequently detected in water samples (present in more than 60% of the samples). Concentrations above 0.1 lg L 1 were detected for 37 of the compounds studied, and in several cases recorded values of over 18 lg L 1. The results reveal the presence of pesticides in most of the samples investigated. In 64% of groundwaters and 62% of surface waters, the sum of compounds detected was higher than 0.5 lg L 1 (the limit established by EU legislation for the sum of all pesticides detected in waters for human use) ; This work was funded by the Spanish Ministry of Science and Innovation (Project AGL2010-15976/AGR). E. Herrero-Hernández, CSIC for his JAE-Doc contracts co-financed by the European Structural and Social Funds (FEDER-FSE) and E. Pose-Juan and A. Alvárez-Martín thank the Spanish Ministry of Science and Innovation for their Juan de la Cierva contract and FPI fellowship, respectively. ; Peer reviewed