The Effects of Formulation on Imidacloprid Dissipation in Grapes and Vine Leaves and on Required Pre-Harvest Intervals under Lebanese Climatic Conditions.

In this study, imidacloprid, a systemic insecticide, currently having a specified European Commission MRL value for vine leaves (2 mg kg-1), was applied on a Lebanese vineyard under different commercial formulations: as a soluble liquid (SL) and water dispersible granules (WDG). In Lebanon, many commercial formulations of imidacloprid are subject to the same critical good agricultural practice (cGAP). It was, therefore, important to verify the variability in dissipation patterns according to matrix nature and formulation type. Random samplings of grapes and vine leaves were performed starting at 2 days until 18 days after treatment. Residue extractions were performed according to the QuEChERS method and the analytical determination using liquid chromatography coupled to tandem mass spectrometry (LC-MS-MS). The SL formulation yielded significantly higher initial deposit than the WDG formulation on grapes and vine leaves. The formulation type did not significantly affect the dissipation rates; the estimated half-lives in grapes and vine leaves were 0.5 days for all imidacloprid formulations. No pre-harvest intervals were necessary on grapes. PHIs of 3.7 days for the SL formulation and 2.8 days for the WDG formulation were estimated on vine leaves. The results showed that the type of formulation and the morphological and physiological characteristics of the matrix had an effect on the initial deposits, and thus residue levels, but not on the dissipation patterns.

Influence of hydrodynamics on the water pathway and spatial distribution of pesticide and metabolite concentrations in constructed wetlands.

Constructed wetlands (CWs) are likely to reduce pesticide levels reaching surface water. However, the distribution of the water flow path between the main channel and isolated areas may influence global pesticide mitigation. Little information is known about the influence of water pathways on pesticide mitigation. Thus, we performed tracer experiments at low and high flow rates (0.5 L/s and 4-7 L/s) in a pond CW and ditch CW to determine the localization of various hydraulic zones and to understand their implication on pesticide mitigation. The hydraulic performance reflecting the fraction of water transported from inlet to outlet passing through the whole of CW, was greater for the pond CW than for the ditch CW regardless of the flow rate, and greater at mean flow rates (MF) than at low flow rates (LF) due to a lower proportion of isolated areas at a MF (11%-68%) than at LF (38%-89%). Dispersion governed the water transport inside the isolated areas and the water convection inside the main channel. Consequently, dissolved pesticide concentrations are heterogeneously distributed in the CWs, i.e., in the main channel and isolated area, for both flow rates. However, one month after a no-flow period, this heterogeneity disappears, and dissolved pesticide concentrations become similar in the water of the whole CW due to dispersion. Furthermore, sedimentation and storage in sediments were greater in the isolated area than in the main channel, which is possibly due to a lower speed flow rate and a higher hydraulic residence time (HRT) in the isolated area than in the main channel. Thus, isolated areas act as effective's zones to mitigate pesticides from dissolved and particulate phases inside the CW during a complete drainage season (i.e., succession of high/low/no-flow periods).

Monitoring of Nitrate and Pesticide Pollution in Mnasra, Morocco Soil and Groundwater.

This study evaluates the levels of nitrates and pesticides occurring in groundwater and agricultural soil in the Mnasra, Morocco area, a zone with intensive agricultural activity. A set of 108 water samples and 68 soil samples were collected from ten selected sites in the area during agricultural seasons, from May 2010 to September 2012. The results reveal that 89.7% of water samples exceeded the standard limit of nitrate concentrations for groundwater (50 mg/L). These results can be explained by the prevailing sandy nature of the soil in the area, the frequency of fertilizer usage, and the shallow level of the water table, which favors the leaching of nitrate from field to groundwater. In contrast, the selected pesticide molecules were not detected in the analysed soil and water samples; levels were below the quantification limit in all samples. This situation could be explained by the probable partial or total transformation of the molecules in soil.

Effect of vine leaves processing on Azoxystrobin, Fenazaquin and Indoxacarb residues dissipation: processing factors and consumer safety assessment.

The effect of vine leaves processing techniques on Azoxystrobin, Fenazaquin, and Indoxacarb residues was investigated. Residue extraction following field application of pesticides and leaf processing was carried out using the QuEChERS method, with analysis conducted by LC-MS/MS. In dry conservation, Azoxystrobin's half-life was estimated to exceed a year, Fenazaquin's was 18 days, and Indoxacarb's was 142 days. Azoxystrobin had a half-life of 261 days, Fenazaquin had a half-life of 9 days, and Indoxacarb's half-life exceeded a year in brine conservation. It is recommended to use dry conservation because it results in an average 60 % reduction in residue levels for the three pesticides. Boiling water significantly reduced pesticide residues (Azoxystrobin -40.3 %, Indoxacarb -22.4 %, and Fenazaquin -28.8 %). It is recommended to use boiling water for washing, as it shows an average removal rate of approximately 30 %. The health risk assessment indicated that consuming vine leaves posed no health risk for consumers, but overall exposure to residues must be considered.

Field-Crop Soils in Eastern France: Coldspots of Azole-Resistant Aspergillus fumigatus.

Triazole fungicides are widely used to treat fungal pathogens in field crops, but very few studies have investigated whether fields of these crops constitute hotspots of azole resistance in Aspergillus fumigatus. Soil samples were collected from 22 fields in two regions of eastern France and screened for triazole residues and azole-resistant A. fumigatus (ARAf). Real-time quantitative PCR (qPCR) was used to quantify A. fumigatus in these soil samples. All the plots contained tebuconazole at concentrations from 5.5 to 19.1 ng/g of soil, and 5 of the 22 plots also contained epoxiconazole. Only a few fungal isolates were obtained, and no ARAf was detected. A. fumigatus qPCR showed that this fungal species was, on average, 5000 times more common in soil from flowerbeds containing ARAf than in soil from field crops. Thus, field-crop soils do not appear to promote A. fumigatus development, even if treated with azole fungicides, and cannot be considered hotspots of resistance. Indeed, our results suggest that they are instead a coldspot of resistance and highlight how little is known about the ecological niche of this species.

Effects of sewage sludge amendments on pesticide sorption and leaching through undisturbed Mediterranean soils.

The Gharb region in Morocco is an important agricultural zone where soils receive pesticide treatments and organic amendments to increase yields. The groundwater aquifer in the Gharb region is relatively shallow and thus vulnerable. The objective of this work was to study the influence of organic amendments on diuron, cyhalofop-butyl and procymidone leaching through undisturbed soil columns. Two soils were sampled from the Gharb region, a Dehs (sandy soil) and a R'mel (loamy clay soil). Following elution (124.5 mm), the amount of pesticide residues in the leachates of the sandy soil (0.06-0.21 %) was lower than in those of the loamy clay soil (0.20-0.36 %), which was probably due to preferential flow through the loamy clay soil. The amount of procymidone leached through the amended soil columns was greater than the control for the sandy soil only. The organic amendments did not significantly influence diuron and cyhalofop-butyl leaching in either of the soils. The application of organic amendments affected the amounts of dissolved organic matter (DOM) eluted and thus pesticide leaching as a function of soil-type. Nevertheless, in some case, the formation of pesticide-DOM complexes appeared to promote pesticide leaching, thus increasing groundwater contamination risks.

Pesticide sorption and mitigation efficiency of a detention pond in a Champagne vineyard catchment.

Detention ponds (DPs) are used to reduce the pesticide inputs from runoff to surface water. This study aimed to assess the role of the sorption process in the mitigation of a DP made up of four successive units and built at the outlet of a vineyard catchment in Champagne (France) to treat runoff waters. Sorption kinetics and isotherms were studied for four pesticides with contrasting properties, cyazofamid (CYA), fludioxonil (FLX), fluopicolide (FLP) and oryzalin (ORY), in the presence of copper in sediments and four emergent macrophyte roots and rhizomes sampled in the DP units 2 (photodegradation) and 3 (phytoremediation). The adsorption equilibrium time (from 24 to 96 h) was less than the hydraulic residence times in the two units (6 and 18 days on average) between November 2016 and November 2017. Sorption equilibrium could then be reached in situ in 85 % of cases. The K d coefficients of the four pesticides were overall greater in plant roots (14-6742 L kg-1) than in sediments (6-163 L kg-1) because of their affinity for organic matter and the molecular and porous structure of the plant matrices. Typha latifolia and Iris pseudacorus exhibited greater K d coefficients than Mentha aquatica and Phragmites australis, probably due to their greater specific surface area. The pesticide adsorption capacity in sediments and in T. latifolia and I. pseudacorus roots (ORY ≥ FLX > CYA > FLP) was linked to their K ow . The estimated total annual amounts of the four pesticides adsorbed in situ were determined to be 1236 mg for unit 2 and 1570 mg for unit 3. The four plants improved the removal efficiency of the unit 3 by 33%. Thus, the establishment of suitable and effective plants should be promoted to optimize sorption processes and DP efficiency in reducing water pollution.

Leaching of Diuron, Linuron and their main metabolites in undisturbed field lysimeters.

The increasing use of pesticides in Morocco raises the potential risk of groundwater contamination, notably in the Gharb area, which has a shallow groundwater table. Thus, the leaching of two phenyl-ureas, diuron and linuron and their metabolites through undisturbed soil columns was studied under outdoor conditions. The soil chosen is a loamy clay soil, representative of the Gharb agricultural area. After four irrigation events were applied from 31/03/2005 to 15/05/2005, leachates contained higher amounts of linuron (from 0.08% to 6.96% of applied linuron) than diuron (from 0% to 0.27%). The greater mobility of linuron might be related to its higher water solubility (64 mg x L(- 1) compared with 42 mg x L(- 1) for diuron) and smaller adsorption coefficient (K(oc) of 400 L x kg(- 1), compared with 480 L x kg(- 1) for diuron). Concerning their metabolites, greater amounts of, N'-(3,4-dichlorophenyl)-N, (DCPMU) than N'-3,4-dichlorophenylurea (DCPU) were detected N-dimethylurea in the percolates, from 0% to 0.046% and from 0% to 0.008%, respectively. At the end of the monitoring period, more linuron residues than diuron residues were recovered in the soil profiles, 25.02% and 16.41%, respectively. The diuron residues were found mainly in the 0-20 cm soil layer, whereas linuron residues reached the 20-40 cm soil layer. Under such experimental conditions, linuron leaching, and thus its potential to contaminate groundwater, is greater than that of diuron.

Is pesticide sorption by constructed wetland sediments governed by water level and water dynamics?

Constructed wetlands (CWs) are used to reduce the pesticide inputs from tile drainage or run-off to surface water. Their effectiveness appears variable and remains to be better characterized and understood. The aim of this study was to assess the influences of two hydraulic parameters (i.e., dynamics and water level) on the sorption process occurring in CWs. Then, two solid/liquid ratios were studied (1/1 and 1/5) to mimic the water level variation in the field, and two agitation speeds were used (none and gentle agitation) to simulate different water dynamics (stagnation and flow pass, respectively). Sorption kinetics and isotherms were obtained for four pesticides with contrasting properties. The pesticide adsorption coefficients were classified as follows: boscalid (BSC) > cyproconazole (CYP) > isoproturon (IPU) ∼ dimethachlor (DMT) at any ratio or agitation, in agreement with their water solubilities and K ow values. The effect of the solid/liquid ratio was evidenced for all conditions. Indeed, the adsorption equilibrium time was reached more quickly for the 1/1 ratio (24-72 h) than for the 1/5 ratio (96-120 h). In addition, the adsorption coefficients (K fads) were larger for the 1/1 ratio (1.8-11.2 L kg-1) than for the 1/5 ratio (1.0-5.9 L kg-1). The agitation effect was more evidenced for the 1/5 ratio and for the more hydrophobic molecules, such as BSC and CYP, for which adsorption equilibrium time was never reached with agitation (>120 h), while it was reached at 96 h without agitation. Moreover, the K fads values were larger with agitation than without agitation for BSC and CYP, whereas they were similar for the two agitations for IPU and DMT. Our results demonstrated that the hydrodynamic function of CWs could influence pesticide sorption with variable effects according to the molecular properties and consequently influence the mitigation effect of CWs throughout the year.

RECOTOX, a French initiative in ecotoxicology-toxicology to monitor, understand and mitigate the ecotoxicological impacts of pollutants in socioagroecosystems.

RECOTOX is a cross-cutting initiative promoting an integrated research to respond to the challenges of monitoring, understanding, and mitigating environmental and health impacts of pesticides in agroecosystems. The added value of RECOTOX is to develop a common culture around spatial ecotoxicology including the whole chain of pressure-exposure-impact, while strengthening an integrated network of in natura specifically equipped sites. In particular, it promotes transversal approaches at relevant socioecological system scales, to capitalize knowledge, expertise, and ongoing research in ecotoxicology and, to a lesser extent, environmental toxicology. Thus, it will open existing research infrastructures in environmental sciences to research programs in ecotoxicology of pesticides.

Leaching of oryzalin and diuron through undisturbed vineyard soil columns under outdoor conditions.

Field studies monitoring herbicide pollution in the vineyards of Burgundy (France) have revealed that drinking water reservoirs are contaminated with several pre-emergence herbicides. An assessment of the leaching of two such herbicides, diuron and oryzalin, was therefore performed using lysimeters, under outdoor conditions, from May 2001 to May 2002. Four vineyard soils from Vosne-Romanée (Burgundy) were chosen along a topolithosequence: a rendosol and three calcosols. After 673 mm of rainfall, greater amounts of diuron than oryzalin were measured in percolates: respectively 0.10-0.84% and 0.02-0.43% of applied herbicide, depending on soils. Measurements for diuron metabolites detected greater amounts of DCPMU than DCPU in the percolates: respectively 0.05-0.13% and 0-0.04% of the applied diuron. At the end of the monitoring period, more residues of diuron than oryzalin were recovered in the soil profiles: respectively 4.6-9% and 1.4-4.4%. The oryzalin residues were found mainly in the upper 10 cm of soil columns, whereas diuron residues were present in the whole core. The mobility of both oryzalin and diuron seems fairly well-related to soil organic carbon content; the mobility of diuron is also related to soil texture (sand and coarse material contents). Under such experimental conditions, this study confirms that diuron leaching, and therefore potential groundwater contamination, is greater than that of oryzalin.

Influence of substrate water saturation on pesticide dissipation in constructed wetlands.

Constructed wetlands are an effective and practical option for removing pesticide pollution from runoff or subsurface drainage water. The objective of this study was to assess the efficiencies of a ditch with a bundle of straw placed in its centre and a vegetated pond installed in grass cover bands at downstream of a drained plot. The dissipation rates of three herbicides and three fungicides were monitored on four substrates commonly found in constructed wetlands (two soils, sediment and straw). The influence of water content was determined in a sequence of three steps (flooded-unsaturated-flooded) over 120 days. The pesticide dissipation rates observed during the 120 days of incubation ranged from 1.4 to 100%. Isoproturon and 2,4-MCPA (MCPA) showed the highest dissipation rates, which ranged from 61.0 to 100% of the applied quantities during the 120 days of incubation. In contrast, boscalid and tebuconazole showed the lowest dissipation rates, which ranged from 1.4 to 43.9% of the applied quantities during the 120 days of incubation. The estimated DT50 values ranged from 20.5 days to more than 1 year and were influenced by the substrate water content. The soil and straw substrates had the lowest DT50 values during the unsaturated conditions, whereas the sediments had the lowest DT50 values during the flooded conditions. These results could be explained by an adaptation of microbial communities to their environmental conditions. Thus, the most favourable conditions of dissipation for soils and straw are observable when the drainage ceases (spring and summer). However, favourable conditions occur all year for the sediments, except when the constructed wetlands are dry. The results suggest that the dissipation of pesticides in constructed wetlands contributes to the long-term effectiveness of these buffer zones for reducing water pollution.

Leaching of glyphosate and AMPA under two soil management practices in Burgundy vineyards (Vosne-Romanée, 21-France).

Some drinking water reservoirs under the vineyards of Burgundy are contaminated with herbicides. Thus the effectiveness of alternative soil management practices, such as grass cover, for reducing the leaching of glyphosate and its metabolite, AMPA, through soils was studied. The leaching of both molecules was studied in structured soil columns under outdoor conditions for 1 year. The soil was managed under two vineyard soil practices: a chemically treated bare calcosol, and a vegetated calcosol. After 680 mm of rainfall, the vegetated calcosol leachates contained lower amounts of glyphosate and AMPA (0.02% and 0.03%, respectively) than the bare calcosol leachates (0.06% and 0.15%, respectively). No glyphosate and only low amounts of AMPA (<0.01%) were extracted from the soil. Glyphosate, and to a greater extent, AMPA, leach through the soils; thus, both molecules may be potential contaminants of groundwater. However, the alternative soil management practice of grass cover could reduce groundwater contamination by the pesticide.

Diuron mobility through vineyard soils contaminated with copper.

The herbicide diuron is frequently applied to vineyard soils in Burgundy, along with repeated treatments with Bordeaux mixture (a blend of copper sulfate and calcium hydroxide) that result in elevated copper concentrations. Cu could in principle affect the fate and transport of diuron or its metabolites in the soil either directly by complexation or indirectly by altering the populations or activity of microbes involved in their degradation. To assess the effect of high Cu concentrations on diuron transport, an experiment was designed with ten undisturbed columns of calcareous and acidic soils contaminated with 17--509 mg kg(-1) total Cu (field-applied). Grass was planted on three columns. Diuron was applied to the soils in early May and in-ground lysimeters were exposed to outdoor conditions until November. Less than 1.2% of the diuron applied was found in the leachates as diuron or its metabolites. Higher concentrations were found in the effluents from the grass-covered columns (0.1--0.45%) than from the bare-soil columns (0.02--0.14%), and they were correlated with increases in dissolved organic carbon. The highest amounts of herbicide were measured in acidic-soil column leachates (0.98--1.14%) due to the low clay and organic matter contents of these soils. Cu also leached more readily through the acidic soils (32.8--1042 microg) than in the calcareous soils (9.5--63.4 microg). Unlike in the leachates, the amount of diuron remaining in the soils at the end of the experiment was weakly related to the Cu concentrations in the soils.

Do constructed wetlands in grass strips reduce water contamination from drained fields?

This study evaluates the efficiency of two small constructed wetlands installed in the regulatory grass strips between a drained plot and a river. The observed nitrate removal efficiencies were independent of the season or type of constructed wetland and ranged from 5.4 to 10.9% of the inlet amounts. The pesticide mass budgets ranged from -618.5 to 100%, depending on the molecule. The negative efficiencies were attributed to runoff and remobilization. In contrast, the highest efficiencies were associated with pesticides with high Koc and low DT50 (half-life) values, suggesting sorption and degradation. However, the effectiveness of these wetlands is limited for pesticides with low Koc or high DT50 values; thus, the use of these molecules must be reduced. Increasing the number of these small, inexpensive and low-maintenance wetlands in the agricultural landscape would reduce the level of water pollution whilst preserving the extent of cultivated land, but their long-term effectiveness should be evaluated.

Microbial acidification and pH effects on trace element release from sewage sludge.

Leaching of sludge-borne trace elements has been observed in experimental and field studies. The role of microbial processes in the mobilization of trace elements from wastewater sludge is poorly defined. Our objectives were to determine trace element mobilization from sludge subjected to treatments representing microbial acidification, direct chemical acidification and no acidification, and to determine the readsorption potential of mobilized elements using calcareous sand. Triplicate columns (10-cm diameter) for incubation and leaching of sludge had a top layer of digested dewatered sludge (either untreated, acidified with H2SO4, or limed with CaCO3; all mixed with glass beads to prevent ponding) and a lower glass bead support bed. Glass beads in the sludge layer, support layer or both were replaced by calcareous sand in four treatments used for testing the readsorption potential of mobilized elements. Eight sequential 8-day incubation and leaching cycles were operated, each consisting of 7.6 d of incubation at 28 degrees C followed by 8 h of leaching with synthetic acid rain applied at 0.25 cm/h. Leachates were analyzed for trace elements, nitrate and pH, and sludge layer microbial respiration was measured. The largest trace element, nitrate and S losses occurred in treatments with the greatest pH depression and greatest microbial respiration rates. Cumulative leaching losses from both microbial acidification and direct acidification treatments were > 90% of Zn and 64-80% of Cu and Ni. Preventing acidification with sludge layer lime or sand restricted leaching for all trace elements except Mo. Results suggested that the primary microbial role in the rapid leaching of trace elements was acidification, with results from direct acidification being nearly identical to microbial acidification. Microbial activity in the presence of materials that prevented acidification mobilized far lower concentrations of trace elements, with the exception of Mo. Trace elements mobilized by acidification were readsorbed by calcareous sand when present.

Laboratory leaching studies of oryzalin and diuron through three undisturbed vineyard soil columns.

The leaching of diuron and oryzalin through undisturbed soil columns was studied in the laboratory using three vineyard soils from Vosne-Romanée (Burgundy): a rendosol, a calcosol and a vegetated calcosol. After 845 mm of simulated rainfall in 15 days, soil leachates contained higher amounts of diuron (3.2%, 11.8% and 18.8% of applied diuron, respectively) than oryzalin (0.2%, 4.9%, 3.7%, respectively). A greater proportion of soil extractable residues was obtained for diuron (42.5%, 26.8% and 32.2%, respectively) than for oryzalin (14.7%, 12% and 15.5%, respectively). The greater mobility of diuron might be related to its higher water solubility (36.4 mgl(-1) compared with 2.6 mgl(-1) for oryzalin) and smaller adsorption coefficient (400 lkg(-1), compared with 700-1100 lkg(-1) for oryzalin). The mobility of the two herbicides was greater in the two calcosols than in the rendosol, not only due to different organic carbon contents but also different soil textures and structures.

Sorption of selected pesticides on soils, sediment and straw from a constructed agricultural drainage ditch or pond.

Buffer zones such as ponds and ditches are used to reduce field-scale losses of pesticides from subsurface drainage waters to surface waters. The objective of this study was to assess the efficiency of these buffer zones, in particular constructed wetlands, focusing specifically on sorption processes. We modelled the sorption processes of three herbicides [2-methyl-4-chlorophenoxyacetic acid (2,4-MCPA), isoproturon and napropamide] and three fungicides (boscalid, prochloraz and tebuconazole) on four substrates (two soils, sediment and straw) commonly found in a pond and ditch in Lorraine (France). A wide range of Freundlich coefficient (K fads) values was obtained, from 0.74 to 442.63 mg(1 - n) L (n) kg(-1), and the corresponding K foc values ranged from 56 to 3,725 mg(1 - n) L (n) kg(-1). Based on potential retention, the substrates may be classified as straw >> sediments > soils. These results show the importance of organic carbon content and nature in the process of sorption. Similarly, the studied pesticides could be classified according to their adsorption capacity as follows: prochloraz >> tebuconazole-boscalid > napropamide >> MCPA-isoproturon. This classification is strongly influenced by the physico-chemical properties of pesticides, especially solubility and K oc. Straw exhibited the largest quantity of non-desorbable pesticide residues, from 12.1 to 224.2 mg/L for all pesticides. The presence of plants could increase soil-sediment sorption capacity. Thus, establishment and maintenance of plants and straw filters should be promoted to optimise sorption processes and the efficiency of ponds and ditches in reducing surface water pollution.

Effectiveness of vetiver grass (Vetiveria zizanioides L. Nash) for phytoremediation of endosulfan in two cotton soils from Burkina Faso.

The influence of vetiver grass (Vetiveria zizanioides) on the fate of endosulfan was studied using a vertisol and a lixisol soils from cotton-growing areas of Burkina Faso. Endosulfan adsorption isotherms were prepared for planted and unplanted soils. Pot experiments were then conducted for six months. For both soils, endosulfan adsorption was higher on planted soils (K(f) = 6.53-9.73 mg(l-n) L(n) kg(-1)) than on unplanted soils (6.27-7.24 mg(l-n) L(n) kg(-1)). In unplanted soils, vertisol adsorbed more endosulfan than lixisol. From the pot experiments, the estimated half-lives of endosulfan in unplanted soils (40.6 to 43.1 days) were higher than in planted soils (34.5 to 40.6 days) containing a greater number of endosulfan-degrading microorganisms. Six months after treatment, endosulfan was not detected in soils. The effectiveness of vetiver in promoting adsorption and the disappearance of endosulfan in both studied soils should be validated on the cotton plot scale in Burkina Faso.

Is vetiver grass of interest for the remediation of Cu and Cd to protect marketing gardens in Burkina Faso?

In Burkina-Faso, urban vegetable agriculture is often characterized by urban solid waste fertilizer inputs containing heavy metals such as Cu and Cd. Thus, the relevance of surrounding urban vegetable plots with vetiver hedges to reduce environmental pollution by Cu and Cd was investigated by adsorption studies and pot experiments. Vetiver biomass, its metal contents and, its total and MgCl2 extractable soil metals were monitored over 6months in the presence of a mixture of metal at two concentrations: 2-10 and 100-500mgkg(-1), for Cd and Cu, respectively. The Freundlich adsorption coefficient (Kf) values increased after vetiver growth and were significantly higher for vertisol than for lixisol. After 6months, the vetiver that was grown on lixisol accumulated more metal, increasing up to 4635mgkg(-1) for Cu and to 21.8mgkg(-1) for Cd, than did the vetiver that was grown on vertisol, increasing up to 1534mgkg(-1) for Cu and to 7.2mgkg(-1) for Cd. The metal bioconcentration factor, which was significantly higher for Cd, increased with the applied concentration and ranged from 1.6 to 14 for Cu and from 2.3 to 22 for Cd. Additionally, the translocation factors were higher for Cd (0.38-7.3) than for Cu (0.07-2.6), and the translocation was easiest from lixisol than from vertisol. Thus our results demonstrate the ability of vetiver for Cu and Cd phytoremediation in Burkina Faso soils. Nevertheless, these results should be confirmed across the field to advocate the establishment of vetiver hedges.