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Field-scale dissipation of tebuconazole in a vineyard soil amended with spent mushroom substrate and its potential environmental impact
Abstract
The persistence, mobility and degradation of tebuconazole were assessed under field conditions in a sandy clay loam soil amended with spent mushroom substrate (SMS) at two rates. The aim was to evaluate the environmental impact of the simultaneous application of SMS and fungicide in a vineyard soil. SMS is the pasteurized and composted organic material remaining after a crop of mushroom is produced. SMS is generated in increasing amounts in La Rioja region (Spain), and could be used as soil amendment in vineyard soils, where fungicides are also applied in large amounts. The study was carried out in 18 experimental plots (6 treatments and 3 replicates per treatment) over one year. Laboratory experiments were also conducted to verify the changes over time in the adsorption of fungicide by soils and in soil dehydrogenase activity caused by the fungicide and/or SMS. Tebuconazole dissipation followed biphasic kinetics with a rapid dissipation phase, followed by a slow dissipation phase. Half-life (DT50) values ranged from 8.2 to 12.4 days, with lower DT50 for amended soils when compared to the non-amended controls. The distribution of tebuconazole through the soil profile (0-50 cm) determined at 124, 209 and 355 days after its application indicated the higher mobility of fungicide to deeper soil layers in amended soils revealing the influence of solid and dissolved organic matter from SMS in this process. Tebuconazole might be available for biodegradation although over time only chemical or photochemical degradation was evident in surface soils. The results obtained highlight the interest of field and laboratory data to design rational applications of SMS and fungicide when they are jointly applied to prevent the possible risk of water contamination.
... In ARN2, neither rate of SMS application significantly increased OM content after two years. Herrero-Hernández et al. [37] have reported a 3.5-6.5 times increase in the OM content in the upper horizon of a sandy loam soil amended with SMS at doses of 40 and 100 Mg ha −1 , but also found that OM content decreased by up to 1.4-1.8 times 355 days after SMS application to a vineyard soil. ...
... Herrero-Hernández et al. [37] have reported a 3.5-6.5 times increase in the OM content in the upper horizon of a sandy loam soil amended with SMS at doses of 40 and 100 Mg ha −1 , but also found that OM content decreased by up to 1.4-1.8 times 355 days after SMS application to a vineyard soil. ...
... The decrease in this FA/HA ratio was greater in the amended ARN2 sandy loam soil eight months after SMS application. In this sandy loam soil, the OC may be more bioaccessible to microorganisms, therefore facilitating this OC evolution [37]. The changes in these indicators were lower for ARN1 than for ARN2, possibly due to a different OC evolution mechanism. ...
Spent mushroom substrate (SMS) is the organic residue generated during mushroom cultivation, and it is being produced in ever-greater quantities around the world. Different applications for this residue have been proposed for its valorization, but its application as a soil amendment could be one of the most sustainable. SMS improves soil quality by increasing its organic matter (OM), thereby enhancing the sustainability of agricultural systems. The objective of this work was to evaluate the effect of the application of two doses of SMS on the chemical, biochemical, and microbiological characteristics of two degraded vineyard soils in La Rioja (Spain) with different textures, as a new regenerative agricultural practice. The variations in organic carbon (OC), micro- and macronutrients, soil microbial biomass (BIO), respiration (RES), dehydrogenase activity (DHA), and the profile of phospholipid fatty acids (PLFAs) extracted from the soils were evaluated over two years. An initial increase in soil OC content was recorded in both soils, although the content that remained over time differed for each site. In general, SMS enhanced DHA, RES, and BIO in the soils, but the effect varied, possibly being conditioned by the availability of OC for soil microorganisms. In general, changes in the soils’ microbial structure after SMS application were not very significant over the two-year experimental period.
... tebuconazole (TCZ) EFSA, 2014b 5-(4-chlorophenyl)-2,2-dimethyl-3-(1,2,4-triazol-1ylmethyl)pentane-1,3-diol Obanda and Shupe, 2009 1-(4-chlorophenyl)-4,4-dimethyl-3-(1,2,4-triazol-1ylmethyl)pentane-2,3-diol FAO, 1994 5-chloro-2-[3-hydroxy-4,4-dimethyl-3-(1,2,4-triazol-1ylmethyl)pentyl]phenol FAO, 1994 1-(4-chlorophenyl)-4,4-dimethyl-3-(1,2,4-triazol-1ylmethyl)pentane-1,3,5-triol FAO, 1994 1-(4-chlorophenyl)-3-hydroxy-4,4-dimethyl-3-(1,2,4triazol-1-ylmethyl)pentan-1-one Calza et al., 2002;Herrero-Hernandez et al., 2011;Potter et al., 2005;Strickland et al., 2004 5-(4-chlorophenyl)-3-hydroxy-2,2-dimethyl-3-(1,2,4triazol-1-ylmethyl)pentanoic acid Obanda and Shupe, 2009 5-(4-chlorophenyl)-3-hydroxy-2,2-dimethyl-5-oxo-3-(1,2,4-triazol-1-ylmethyl)pentanoic acid FAO, 1994 [5-(4-chlorophenyl)-3-hydroxy-2,2-dimethyl-3-(1,2,4triazol-1-ylmethyl)pentyl]acetate Obanda and Shupe, 2009 [5-(4-chlorophenyl)-3-hydroxy-2,2-dimethyl- 2-imino-3-(1,2,4-triazol-1-yl)propanoic acid Schermerhorn et al., 2005 2-(1,2,4-triazol-1-yl)ethanimine Schermerhorn et al., 20051H-1,2,4-triazol-5-ol FAO, 19941H-1,2,4-triazole EFSA, 2008FAO, 1994;Schermerhorn et al., 2005;U.S. EPA, 1990. Herbicides and respiration flush of soil biomass. ...
... The literature search revealed that studies reporting TCZ dissipation often ignored the occurrence of potential TPs and mainly followed targeted analytical approaches (Sehnem et al., 2010;Woo et al., 2010). It is noteworthy that non-target approaches resulted in the detection of previously unknown TPs in studies looking at the degradation of TCZ in bacterial or fungal cultures (Obanda and Shupe, 2009), during photolysis (Calza et al., 2002), in field studies (Herrero-Hernandez et al., 2011;Potter et al., 2005), in microcosm studies (Strickland et al., 2004;White et al., 2010) and in fruit (Schermerhorn et al., 2005). Additional information was found in regulatory documents mainly citing unpublished or confidential studies reporting TPs in soil and crops, partially based on MS and NMR spectroscopy FAO, 1994;U.S. EPA, 1990). ...
... In accordance with previous studies , the persistence of TCZ increased with increasing applied doses in both studies. As commonly found in previous studies (Herrero-Hernandez et al., 2011;Wang et al., 2015), TCZ was more persistent in the microcosm than in the field study. DT50-values of TCZ ranged between 60 and 97 days in the microcosm study, which is in the range of DT50-values found in the literature (Strickland et al., 2004;. ...
... The spent mushroom substrate is rich in organic matter and therefore, it can adsorb pesticides and reduces their bioavailability. In a study, conducted by Herrero-Hernández et al. (2011) for tebuconazole distribution in soil was assessed in the soil depth upto 50 cm after 124, 209 and 355 days of application of spent mushroom substrate. The study revealed the higher level of fungicide in the deep layer of amended soil compared to non-amended soil. ...
... The spent mushroom substrate was reported to bind with the pesticide to immobilize it and further, prevents its spreading in the soil. Application of spent mushroom substrate and fungi together in the field requires validation of data by comparing the field data and laboratory data in order to prevent water and soil contamination (Herrero-Hernández et al. 2011). This also prevents the leaching of pesticides in soil and ground water. ...
... Moreover, it is economic technique to implement in the field. A few studies conducted in the field shed the light on the suitability of spent mushroom substrate for adsorption of pollutants (Herrero-Hernández et al. 2011). ...
The edible and non-edible varieties of mushroom can be used as a green adsorbent and can be used in modified and natural form for the adsorption of dyes, pollutants and heavy metals. However, the use of edible mushroom varieties in the adsorption of pollutants is not judicious because edible mushrooms have good nutritive and medicinal properties and can be used for consumption. Recent research is thus focused on the utilization of spent mushrooms. Spent mushroom substrate, generated as waste by mushroom industries after the harvesting of mushroom, and hence, is the source of immobilized mushroom mycelium. The species of mushroom Agaricus, Pleurotus, Lentinus, Calocybe are efficient adsorbents with 70–90% removal of pollutants in laboratory conditions. Spent mushroom substrates can also remove pollutants such as dyes, heavy metals, pesticides and fungicides in laboratory conditions with comparable efficiency as mushroom. Chemisorption and physisorption processes are involved in the adsorption. The data of adsorption are well fitted to Langmuir isotherm, revealing the involvement of monolayer adsorption irrespective of the use of mushroom fruit bodies or spent mushroom substrate. Fourier-transform infrared spectroscopic analysis reveal the presence of carboxyl, hydroxyl, amino group in the adsorption of pollutants, dyes and heavy metals.
... The tebuconazole adsorption was controlled by the soil organic matter (SOM) and clay faction ( Cadcov a et al., 2013a( Cadcov a et al., , 2012. Also, the addition of organic amendments has been found to increase its retention in temperate soils ( Alvarez-Martín et al., 2016b;Fernandes et al., 2006;Fenoll et al., 2011;Herrero-Hern andez et al., 2011;Marín-Benito et al., 2012;Rodríguez-Cruz et al., 2007). Tebuconazole exhibits high to low mobility in soil (Aldana et al., 2011;Cadcov a et al., 2013aCadcov a et al., , 2012EFSA, 2014;G amiz et al., 2016;Herrero-Hern andez et al., 2011;Vall ee et al., 2014) and tends to be pH independent in temperate soils (EFSA, 2014;Cadcov a et al., 2013b). ...
... Also, the addition of organic amendments has been found to increase its retention in temperate soils ( Alvarez-Martín et al., 2016b;Fernandes et al., 2006;Fenoll et al., 2011;Herrero-Hern andez et al., 2011;Marín-Benito et al., 2012;Rodríguez-Cruz et al., 2007). Tebuconazole exhibits high to low mobility in soil (Aldana et al., 2011;Cadcov a et al., 2013aCadcov a et al., , 2012EFSA, 2014;G amiz et al., 2016;Herrero-Hern andez et al., 2011;Vall ee et al., 2014) and tends to be pH independent in temperate soils (EFSA, 2014;Cadcov a et al., 2013b). ...
... Therefore, 24 h was the equilibration time for the tebuconazole adsorption-desorption studies due to the amount of fungicide adsorbed on Inceptisol and Histosol soils remained constant at this time. Other adsorption studies have applied tebuconazole and triazoles fungicides for 24 h in soils (Cox et al., 2004;G amiz et al., 2016;Herrero-Hern andez et al., 2011;Rodríguez-Cruz et al., 2008), this period being generally sufficient to establish the chemical equilibrium of adsorption (fungicide adsorbed) between adsorbent (solid phase) and soil solution (Mosquera-Vivas et al., 2016b;OECD, 2000). Table 2 summarizes the Freundlich adsorption coefficients K fa , the relative magnitude and heterogeneity of energies associated with a particle-adsorption process na, the coefficient of distribution K d , and the coefficients of determination R 2 , calculated to fit experimental adsorption isotherms of tebuconazole to the Freundlich and linear equations as well as the K foc and K oc values. ...
The adsorption-desorption, hysteresis phenomenon, and leachability of tebuconazole were studied for Inceptisol and Histosol soils at the surface (0–10 cm) and in the subsurface (40–50 cm) of an agricultural region from Colombia by the batch-equilibrium method and mathematical approaches. The experimental Kfa and Kd (L kg⁻¹) values (7.9–289.2) decreased with depth for the two Inceptisols and increased with depth for the Histosol due to the organic carbon content, aryl and carbonyl carbon types. Single-point and desorption isotherms depended on adsorption reversibility and suggested that tebuconazole showed hysteresis; which can be adequately evaluated with the single-point desorption isotherm and the linear model using the hysteresis index HI. The most suitable mathematical approach to estimate the adsorption isotherms of tebuconazole at the surface and in the subsurface was that considering the combination of the n-octanol-water partition coefficient, pesticide solubility, and the mass-balance concept.
Tebuconazole had similar moderate mobility potential as compared with the values of other studies conducted in temperate amended and unamended soils, but the risk of the fungicide to pollute groundwater sources increased when the pesticide reached subsurface soil layers, particularly in the Inceptisols.
... The retention process of a wide number of pesticides (22 compounds, Table 2), mainly fungicides, on soils modified by SMS has been reported [15,[30][31][32][33][34][35]41,42]. In these studies, different variables, such as the SMS amendment rate, the type of SMS in terms of nature and treatment (composted or fresh), and the SMS-soil incubation time, have been studied to analyze the modification of pesticide adsorption/desorption when they are applied together with the SMS in soils. ...
... This decrease was linked to changes in the OC content over time, as reported in the literature for other fungicides in SMS-amended soils incubated under laboratory conditions [32]. Conversely, Herrero-Hernández et al. [34] observed that the addition of composted SMS (from Agaricus bisporus (75%) and Pleurotus spp. (25%) production) to a sandy loam soil (OC 1.31%) in the field at rates of 40 and 100 t SMS ha −1 increased the adsorption of tebuconazole, not only after the addition of the residue, but also over time despite the decrease in the OC content of the amended soils. ...
... Herrero-Hernández et al. [33,34] have studied the mobility of tebuconazole and azoxystrobin in a sandy loam soil (OC 1.31%) in vineyard field plots amended with SMS at different rates between 40 and 150 t·ha −1 . The fungicides tebuconazole and azoxystrobin were applied at two doses (0.25 and 1.25 kg·ha −1 ), and soil cores were collected at a depth of up to 50 cm over one year. ...
Intensive crop production involves a high consumption of pesticides. This is a cause of major environmental concern because the presence of pesticides in water is becoming increasingly common. Physicochemical methods based on soil modification with organic residues have been developed to enhance the immobilization and/or degradation of pesticides in agricultural soils, which may control both the diffuse and the point pollution of soils and waters. This review summarizes the influence of spent mushroom substrate (SMS) on the environmental fate of pesticides when both are simultaneously applied in agriculture. The processes of adsorption, leaching and dissipation of these compounds in SMS-amended soils were evaluated at laboratory and field scale. Relationships were established between the experimental parameters obtained and the properties of the soils, the SMS, and the pesticides in order to determine the effect that the application of SMS in agricultural soils has on the environmental impact of pesticides. Accordingly, this review highlights the use of SMS as a strategy for the prevention and/or control of soil and water contamination by pesticides to strike a balance between agricultural development and the use of these compounds.
... TCZ showed a limited persistence in the field with DT 50 values of 1.5-2.5 days for the different dose rates. Previous field studies have also showed a lower persistence of TCZ in the field compared to the laboratory (Herrero-Hernández et al., 2011;Wang et al., 2015). Despite that, the DT 50s obtained for TCZ in the field study are at the lower part of the range of DT 50 values reported in the literature which vary from 5.8-6.5 days (temperature15-30°C) (Wang et al., 2015) to 91.6 days (average temperature 10.5°C) (EFSA, 2014). ...
... The rapid decline of TCZ observed in the field study during the first 3 days after application could not be attributed to a rapid degradation of TCZ as it is indicated by the moderate to high persistence of the compound in the laboratory where degradation, biotic or abiotic, constitutes the main dissipation process. Rapid formation of bound residues or movement of the pesticide below the top 10 cm of the soil have been proposed by Herrero-Hernández et al. (2011) as possible reasons to explain the initial rapid field dissipation of TCZ. The rapid formation of bound residues of TCZ is not fully supported by the moderate soil adsorption affinity of TCZ and previous regulatory studies which reported the formation of only 19.5% of soil bound residues after 30 days (EFSA, 2014). ...
... A precipitation event occurred at day 3 (Supplementary Data Fig. 2), right before the collection of the soil samples, might have facilitated the vertical leaching of a large fraction of TCZ residues below the top 10 cm which was the soil layer sampled. Regarding the second slow dissipation phase of TCZ, it could be attributed to a strongly adsorbed fraction of the pesticide that could be less accessible to dissipation processes (Muñoz-Leoz et al., 2011;Herrero-Hernández et al., 2011). Previous studies have identified four main transformation products of TCZ: a lactone, a pentanoic acid, a triazolyl pinacoline, and a 5-keto derivative (Strickland et al., 2004;Potter et al., 2005). ...
Assessment of dissipation constitutes an integral part of pesticides risk assessment since it provides an estimate of the level and the duration of exposure of the terrestrial ecosystem to pesticides. Within the frame of an overall assessment of the soil microbial toxicity of pesticides, we investigated the dissipation of a range of dose rates of three model pesticides, isoproturon (IPU), tebuconazole (TCZ), and chlorpyrifos (CHL), and the formation and dissipation of their main transformation products following a tiered lab-to-field approach. The adsorption of pesticides and their transformation products was also determined. IPU was the least persistent pesticide showing a dose-dependent increase in its persistence in both laboratory and field studies. CHL dissipation showed a dose-dependent increase under laboratory conditions and an exact opposite trend in the field. TCZ was the most persistent pesticide under lab conditions showing a dose-dependent decrease in its dissipation, whereas in the field TCZ exhibited a biphasic dissipation pattern with extrapolated DT90s ranging from 198 to 603.4days in the ×1 and ×2 dose rates, respectively. IPU was demethylated to mono- (MD-IPU) and di-desmethyl-isoproturon (DD-IPU) which dissipated following a similar pattern with the parent compound. CHL was hydrolyzed to 3,5,6-trichloro-2-pyridinol (TCP) which dissipated showing a reverse dose-dependent pattern compared to CHL. Pesticides adsorption affinity increased in the order IPU<TCZ<CHL. IPU transformation products showed low affinity for soil adsorption, whereas TCP was weakly adsorbed compared to its parent compound. The temporal dissipation patterns of the pesticides and their transformation products will be used as exposure inputs for assessment of their soil microbial toxicity.
... Previous studies have reported the dissipation of some fungicides in a vineyard soil amended with fresh and re-composted SMS (Marín-Benito et al., 2012b). Furthermore, Herrero-Hernández et al. (2011) have studied the dissipation of tebuconazole in a vineyard soil amended with SMS under field conditions. Both studies highlight the effect of SMS characteristics on the dissipation of fungicides. ...
... Tebuconazole is a hydrophobic fungicide with low solubility in water, and it degrades slowly in soil (DT 50 N 365 days; very persistent), being slightly mobile (Kfoc = 769) (PPDB, 2015). Tebuconazole dissipation has been studied mainly in unamended soils (Strickland et al., 2004;Potter et al., 2005;EFSA, 2008b, Fenoll et al., 2011, but there is little information on its dissipation in amended soils (Herrero-Hernández et al., 2011). Tebuconazole and cymoxanil have been detected at concentrations of up to 3.2 µg L -1 and 0.9 µg L -1 in surface and ground waters, respectively, from La Rioja region (Spain), exceeding the EU's 0.1 μg L −1 limit (Herrero-Hernández et al. 2013). ...
... In turn, the dissipation kinetics of cymoxanil in all the soils studied fitted the SFO model better. Previous works have reported the dissipation curves of tebuconazole in unamended and amended soils fitted to a SFO or a biphasic model (Strickland et al., 2004;Potter et al., 2005;Herrero-Hernández et al., 2011). The dissipation kinetics of cymoxanil in unamended soils was fitted to SFO or FOMC models in previous studies (EFSA, 2008a). ...
Physicochemical methods to immobilize pesticides in vulnerable soils are currently being developed to prevent water contamination. Some of these methods include the use of different organic residues to modify soils because they could limit the transport of pesticides and/or facilitate their dissipation. Spent mushroom substrate (SMS) may be used for these purposes. Accordingly a study was conducted under laboratory conditions to know the dissipation and bioavailability of the fungicides cymoxanil and tebuconazole over time in a vineyard soil amended with two rates of spent mushroom substrate (SMS) (5% and 50% (w/w)), selected to prevent the diffuse or point pollution of soil. The dissipation of cymoxanil was more rapid than that of tebuconazole in the different soils studied. The dissipation rate was higher in the amended soil than in the unamended one for both compounds, while no significant differences were observed between the amended soils in either case. An apparent dissipation occurred in the amended soil due to the formation of non-extractable residues. Bound residues increased with incubation time for tebuconazole, although a proportion of this fungicide was bioavailable after 303 days. The major proportion of cymoxanil was tightly bound to the amended soil from the start, although an increasing fraction of bound fungicide was bioavailable for mineralization. Soil dehydrogenase activity was significantly affected by SMS application and incubation time; however, it was not significantly modified by fungicide application. The significance of this research suggests that SMS applied at a low or high rate to agricultural soil can be used to prevent both the diffuse or point pollution of soil through the formation of non-extractable residues, although more research is needed to discover the time that fungicides remain adsorbed into the soil decreasing either bioavailability (tebuconazole) or mineralization (cymoxanil) in SMS-amended soils.
... In latter stages dissipation was little slower irrespective of dose and season. Distinctive biphasic dissipation was also observed by Herrero-Hernández et al. [25] for tebuconazole in field soil. ...
... days) [28] and in field soil amended with and without spent mushroom (T 1/2 = 8.2-12.4 days) [25]. Dissipation rate of tebuconazole in this study was more rapid than described in previous laboratory studies [29][30][31]. ...
... Like many other pesticides [32], a trend towards reduced dissipation values was observed in field versus those in laboratory studies. The rapid decrease in fungicide concentration observed in the field soil may be attributed to the movement or transformation of the compound or bound residue formation [25]. ...
In the present study, dissipation and residue dynamics of tebuconazole in peanut plant and soil and final residue in peanut plant, kernel and soil were carried out. Tebuconazole was applied at recommended dose (187.5 g a. i. ha−1) and double recommended dose to cropped plots following two foliar applications at an interval of ~15 days between 40 and 60 days after sowing of peanut for two consecutive years. The dissipation experiments showed faster degradation of tebuconazole in plant (half-lives: 3.2–5.5 days; degradation rate constant: 0.1267–0.2142 day−1) than soil (half-lives: 9.6–12.5 days; degradation rate constant: 0.0553–0.0725 day−1) in both the season. At harvest, soil, plant and peanut kernel samples were found to contain no residues of tebuconazole irrespective of doses and season, indicating tebuconazole is safe from the human and environmental contamination point of view.
... Consequently, both field studies and laboratory studies are needed to provide complete information on how pesticides dissipate under natural conditions. In general, there are few studies on dissipation in the field (Papiernik et al., 2007;Chai et al., 2009), with only a handful examining the influence of different organic amendments on pesticide dissipation (Dolaptsoglou et al., 2009;Herrero-Hern andez et al., 2011a). Very few studies have evaluated the dissipation of pesticides under field and laboratory conditions simultaneously (Ahmad et al., 2003;Potter et al., 2005;Chai et al., 2013). ...
... Spent mushroom substrate was supplied by INTRAVAL Environmental Group TRADEBE S.L. (Spain). Its composition was described by Herrero-Hern andez et al. (2011a) and their physicochemical characteristics determined as described in this previous work are: pH 7.5, organic carbon (OC) content 27.1% and dissolved organic carbon (DOC) content 1.22%. ...
... Five topsoil samples were collected from 0 to 10 cm at 0,2,7,14,21,28,35,84,115,150,181,235,300 and 378 days after treatment to determine fungicide dissipation and five soil cores were collected to a depth of 50 cm after 84, 181 and 378 days of azoxystrobin application to determine mobility of fungicide. Soil samples were managed as indicated in Herrero-Hern andez et al. (2011a). ...
... Soil dehydrogenase activity Fig. 1 represents the evolution of DHA for both soils along incubation. Soil DHA reflects the total range of oxidative activity of soil microflora and, consequently, it is frequently used as an indicator of soil microbiological activity in soil (Hernández-Soriano et al., 2009;Herrero-Hernández et al., 2011). ...
... In general it can be concluded that DHA is higher for S2 than for S5 and higher for the corresponding non-sterile soils. Non-sterile soils behave similarly with a maximum at the beginning of the incubation and reaching a constant value thereafter, when soil enzymatic activity stabilises (Hernández-Soriano et al., 2009;Herrero-Hernández et al., 2011;Marín-Benito et al., 2012). The higher DHA values for S2 soil are probably due to higher nutrient availability and OC content (Table 1) (Yuan and Yue, 2012;Velmourougane et al., 2013). ...
... However in some cases the estimated decay data of both pesticides showed a poor agreement with the measured pesticide concentrations. Deviations from the SFO kinetic model have been reported in the literature (Sánchez et al., 2003;Delgado-Moreno and Peña, 2009;Hernández-Soriano et al., 2009;Herrero-Hernández et al., 2011;Marín-Benito et al., 2012). ...
... Agaricus bisporus spent substrate has been used as component in the diet of carp [15]. Spent substrate were investigated in a study to degradation and remove pesticide in some areas and were found to be very effective in their application [16]. ...
... In previous studies it shows that SMC such as straws can be combusted in a bubbling fluidized-bed to generate power with high efficiency [20]. Herrero-Hernández et al. [16] reported that SMS is the best suit for adsorption of pollutants which can be reused and recycled for the adsorption of pollutants as many times as possible by using different chemical treatments and by modifying it in activated carbon form. The spent mushroom substrate work by binding with positive charge metals whereby adsorbs metals which are present in the solution and involved in metal chelation [3,21]. ...
... In soil, TBZ can be transformed by abiotic (Calza et al., 2002), and biotic processes ( Strickland et al., 2004). Although TBZ has been available on the market for 30 years and is considered to be biodegradable (EFSA, 2008a;FAO, 1994), only a few authors have reported on its biodegrada- tion in the environment ( Komarek et al., 2010;Herrero-Hernandez et al., 2011;Stamatis et al., 2010), in soil microcosms ( Strickland et al., 2004), in saturated constructed wetland mesocosms ( Lv et al., 2016) and in microbial cultures ( Obanda and Shupe, 2009;Obanda et al., 2008;Sehnem et al., 2010). ...
... TPs 35 and 37 described by Strickland et al. (2004), Storck et al. (2016) and Potter et al. (2005) respectively) which are further trans- formed to 2-(1,2,4-triazol-1-yl)acetic acid (TP 42). Alternatively in hy- pothetical pathways 2 and 3, TBZ is subjected to one or more hydroxylation reactions which as an example, results in the formation of TP 11 in the pathway 3 (Fig. S4), identified as an intermediate of TBZ in previous studies (Herrero-Hernandez et al., 2011;Potter et al., 2005;Strickland et al., 2004). Hydroxylated intermediates are cleaved to 1-(4-chlorophenyl)ethanone (identified and quantified for the first time in this study), and various hydroxylated triazole TPs. ...
Tebuconazole (TBZ) is a widely used triazole fungicide at EU level on cereals and vines. It is relatively persistent in soil where it is transformed to various transformation products (TPs) which might be environmentally relevant. We assessed the dissipation of TBZ in soil under contrasting incubation conditions (standard vs winter simulated) that are relevant to its application scheme, determined its transformation pathway using advanced analytical tools and 14C-labeled TBZ and assessed its soil microbial toxicity. Mineralization of 14C-triazole-ring-labeled TBZ was negligible but up to 11% of 14C-penyl-ring-labeled TBZ evolved as 14CO2 within 150 days of incubation. TBZ persistence increased at higher dose rates (×10 compared to the recommended agronomical dose ×1) and under winter simulated conditions compared to standard incubation conditions (at ×1 dose rate DT50 of 202 and 88 days, respectively). Non-target suspect screening enabled the detection of 22 TPs of TBZ, among which 17 were unknown. Mass spectrometry analysis led to the identification of 1-(4-chlorophenyl) ethanone, a novel TP of TBZ, the formation of which and decay in soil was determined by gas chromatography mass spectrometry. Three hypothetical transformation pathways of TBZ, all converging to 1H-1,2,4-triazole are proposed based on suspect screening. The ecotoxicological effect of TBZ and of its TPs was assessed by measuring by qPCR the abundance of the total bacteria and the relative abundance of 11 prokaryotic taxa and 4 functional groups. A transient impact of TBZ on the relative abundance of all prokaryotic taxa (except α-proteobacteria and Bacteroidetes) and one functional microbial group (pcaH-carrying microorganisms) was observed. However the direction of the effect (positive or negative) varied, and in certain cases, depended on the incubation conditions. Proteobacteria was the most responsive phylum to TBZ with recovery observed 20 days after treatment. The ecotoxicological effects on the soil microorganisms were not correlated with 1-(4-chlorophenyl) ethanone.
... Tebuconazole has a water solubility of 36 mg L À1 and an octanol-water partition coefficient (log P) of 3.7 (Tomlin, 2006). Accordingly, it is strongly sorbed by soil organic matter and slightly mobile in soil (Aldana et al., 2011;Cadková et al., 2013;Herrero-Hernández et al., 2011;Vallée et al., 2013). Metalaxyl has a water solubility of 8400 mg L À1 and a log P of 1.75 (Tomlin, 2006). ...
... It is highly polar and mobile in soils and besides organic matter, certain soil clay minerals may play an important role in its sorption (Bermúdez-Couso et al., 2011;Fernandes et al., 2003;Gondar et al., 2013;Sharma and Awasthi, 1997). The addition of organic amendments and modified clay minerals has been shown to enhance the retention of tebuconazole and/or metalaxyl in soils (Fenoll et al., 2011;Fernandes et al., 2006;Herrero-Hernández et al., 2011;Marín-Benito et al., 2012;Rodríguez-Cruz et al., 2007). ...
Laboratory and field experiments were conducted to assess how the addition of oleate-modified hydrotalcite (clay) and biochar (BC) to an agricultural soil affected the sorption, leaching, persistence, and enantiomeric composition of soil residues of two chiral fungicides, tebuconazole and metalaxyl. Laboratory experiments showed that the sorption of both fungicides ranked as follows: unamended soil < BC-amended soil < clay-amended soil. The addition of clay at a rate of 1% increased metalaxyl soil sorption coefficient (Kd) from 0.34 to 3.14 L kg−1 and that of tebuconazole from 2.4 to 47.4 L kg−1. In our experimental set-up, field plots were either unamended or amended with clay (2 t ha−1) or BC (4 t ha−1), and subsequently treated with a mixture of tebuconazole and metalaxyl at 3 and 6 kg ha−1, respectively. The leaching, persistence, and enantiomer composition of fungicides residues were monitored by sampling at different soil depths (0–5, 5–10, 10–20 cm) for 98 days. No significant changes in the scarce mobility and long persistence of tebuconazole upon amending the soil with clay or BC were observed. In contrast, sorption to clay and BC particles reduced the leaching and degradation of metalaxyl and the clay increased its persistence in the topsoil compared to the unamended soil. The enantioselective analysis of tebuconazole and metalaxyl soil residues indicated that tebuconazole remained mostly racemic along the experiment, whereas for metalaxyl the concentration of S-enantiomer was greater than the concentration of R-enantiomer, more so at longer experimental times and deeper horizons. Nevertheless, for the top 0–5 cm soil layer metalaxyl remained more racemic in clay- and BC-amended soil than in unamended soil. Our results show that addition of amendments with high sorptive capacities can be beneficial in reducing leaching and degradation losses of chiral pesticide enantiomers from the topsoil, and that sorption by the amendments can influence the final enantiomeric composition of pesticide residues.
... They play key roles in soil ecosystem functions, including pollutant biodegradation, biogeochemical cycling and soil formation (Gianfreda and Rao, 2008;Singh et al., 2014). These communities could be potentially impacted by pesticide application to soil (Bending and Rodríguez-Cruz, 2007) or by the use of organic residues (Poulsen et al., 2013) either as soil amendments (Herrero-Hernández et al., 2011) or as a tool to protect water contamination by these compounds (Álvarez-Martín et al., 2016). Therefore it is important to understand how these different agricultural practices affect microbial community structure and functioning. ...
... In the case of SMS, previous reports have shown that the addition of this amendment to soil stimulates the soil microbial biomass and the activities of the soil microbial community (Pérez-Piqueres et al., 2006;García-Delgado et al., 2015) and can inhibit or stimulate degradation of pesticides depending on the nature and stabilization of SMS and pesticide properties (Herrero-Hernández et al., 2011;Marín-Benito et al., 2012b;Marín-Benito et al., 2014). ...
Pesticides and organic amendments are widely used in agricultural soils, the former for pest control and to improve crop yield, and the latter to maintain soil quality and to mitigate pesticide leaching. Both amendments and pesticides can affect soil microbial communities, which may impact crop fitness. Therefore, the objective of the current study was to investigate the changes that occur to soil microbial communities following use of the low-cost organic residue spent mushroom substrate (SMS) (2% and 5% on a dry weight basis) as an amendment to an agricultural soil in combination with the widely used pesticides azoxystrobin or pirimicarb (at 2 and 25 mg kg−1 rates). Dissipation experiments showed that azoxystrobin was more persistent than pirimicarb over the incubation time (90 days). The half-life (DT50) values of azoxystrobin (2 mg kg−1) and pirimicarb (2 and 25 mg kg−1) decreased, while DT50 values of azoxystrobin (25 mg kg−1) increased when SMS was applied to soil. Broad-scale methods such as soil dehydrogenase activity (DHA) and soil respiration showed that SMS rate, pesticide dose and incubation time all affected microbial community metabolism. DHA increased in SMS-amended soils and increased (azoxystrobin) or decreased (pirimicarb) over incubation time. Respiration increased in the soils when the concentration of the pesticide increased and decreased with increasing incubation time. Illumina MiSeq analysis of 18S rRNA genes demonstrated a strong effect of the SMS and incubation time, but not the pesticides, on micro-eukaryote community composition.
... straw, and a humified organic substrate like peat or compost. Spent mushroom substrate (SMS) has been studied lately for its effect in the environmental fate of pesticides and its use in biobeds (Herrero-Hernández et al., 2011;Rodríguez-Cruz et al., 2012;Álvarez-Martín et al., 2016;Marín-Benito et al., 2016;Alves et al., 2022). Karas et al. demonstrated the high depuration capacity of SMS-based biobed packing material so, in the present study, a biomixture composed of SMS, straw and soil was used (Karas et al., 2015). ...
Agro-food processing industries generate large amounts of pesticide-contaminated effluents that pose a significant environmental threat if managed improperly. Biopurification systems like biobeds could be utilized for the depuration of these effluents although direct evidence for their efficiency are still lacking. We employed a column leaching experiment with pilot biobeds to (i) assess the depuration potential of biobeds against fungicide-contaminated effluents from seed-producing (carboxin, metalaxyl-M, fluxapyroxad), bulb-handling (thiabendazole, fludioxonil and chlorothalonil) and fruit-packaging (fludioxonil, imazalil) industries, (ii) to monitor microbial succession via amplicon sequencing and (iii) to determine the presence and dynamics of mobile genetic elements like intl1, IS1071, IncP-1 and IncP-1ε often associated with the transposition of pesticide-degrading genes. Biobeds could effectively retain (adsorbed but extractable with organic solvents) and dissipate (degraded and/or not extractable with organic solvents) the fungicides that were contained in the agro-industrial effluents with 93.1–99.98% removal efficiency in all cases. Lipophilic substances like fluxapyroxad were mostly retained in the biobed while more polar substances like metalaxyl-M and carboxin were mostly dissipated or showed higher leaching potential like metalaxyl-M. Biobeds supported a bacterial and fungal community that was not affected by fungicide application but showed clear temporal patterns in the different biobed horizons. This was most probably driven by the establishment of microaerophilic conditions upon water saturation of biobeds, as supported by the significant increase in the abundance of facultative or strict anaerobes like Chloroflexi/Anaerolinae, Acidibacter and Myxococcota. Wastewater application did not affect the dynamics of mobile genetic elements in biobeds whose abundance (intl1, IS1071, IncP-1ε) showed significant increases with time. Our findings suggest that biobeds could effectively decontaminate fungicide-contaminated effluents produced by agro-food industries and support a rather resilient microbial community.
... Tebuconazole showed its highest concentrations in HRV (median 0.03 ng/m 3 ). This fungicide is widely used on grapes (main crop in HRV) to control fungal infections (Herrero-Hernández et al., 2011). It is moderately persistent in the soil (half-life between 26 and 92 days), explaining its maintenance in air during the study (PPDB, 2014). ...
For decades pesticides have been used in agriculture, however, the occurrence of legacy organochlorine pesticides (OCPs) and current-use pesticides (CUPs) is poorly understood in Africa. This study investigates air concentrations of OCPs and CUPs in three South African agricultural areas, their spatial/seasonal variations and mixture profiles.
Between 2017 and 2018, 54 polyurethane foam-disks passive air-samplers (PUF-PAS) were positioned in three agricultural areas of the Western Cape, producing mainly apples, table grapes and wheat. Within areas, 25 CUPs were measured at two sites (farm and village), and 27 OCPs at one site (farm). Kruskal-Wallis tests investigated area differences in OCPs concentrations, and linear mixed-effect models studied differences in CUPs concentrations between areas, sites and sampling rounds.
In total, 20 OCPs and 16 CUPs were detected. A median of 16 OCPs and 10 CUPs were detected per sample, making a total of 11 OCPs and 24 CUPs combinations. Eight OCPs (trans-chlordane, o,p’-/p,p’-dichlorodiphenyldichloroethylene (DDE)/dichlorodiphenyltrichloroethane (DDT), endosulfan sulfate, γ-hexachlorocyclohexane and mirex) and two CUPs (carbaryl and chlorpyrifos) were quantified in all samples. p,p’-DDE (median 0.14 ng/m³) and chlorpyrifos (median 0.70 ng/m³) showed the highest concentrations throughout the study. Several OCPs and CUPs showed different concentrations between areas and seasons, although CUPs concentrations did not differ between sites. OCPs ratios suggest ongoing chlordane use in the region, while DDT and endosulfan contamination result from past-use.
Our study revealed spatial and seasonal variations of different OCPs and CUPs combinations detected in air. Further studies are needed to investigate the potential cumulative or synergistic risks of the detected pesticides.
... However, these chemistry and toxicity data of the target soil resulted from temporarily short-term experiments. Only in situ soil dehydrogenase activity in soils treated with tebuconazole or azoxystrobin and amended with spent mushroom substrate was investigated in a periodic long-term experiment, over 355 or 378 days [9,10]. This traced the change of in situ soil dehydrogenase activity induced from tebuconazole or azoxystrobin over time (0, 36, 92, 124, 355 days or 0, 28, 84, 181, 378 days). ...
Various pollutants are pervasive in soil environments due to human activities, thereby damaging soil ecosystems. In this study, extension of a previously developed algae-soaked disc seeding assay for periodic evaluation of subsoil contamination over time was described. The assay can be used in different contamination configurations of silver nanoparticles in combination with examination of cell morphology, esterase activity, oxidative stress, and membrane permeability. In addition, we periodically attempted to repeat the algae-soaked disc seeding assay every three weeks. We evaluated applicability of this algae-soaked disc seeding assay using alga Chlamydomonas reinhardtii exposed to heterogeneous silver nanoparticle-contaminated soils. The results demonstrated that this assay is applicable for monitoring a change of subsoil contamination by periodic evaluation over time. The developed assay was identified as a periodically rapid in situ biomonitoring technique to measure subsoil contamination over time.
... Taken into account, few previous studies documented the residue behavior of cymoxanil. In a previous study, Tebuconazole and cymoxanil have been detected at concentrations of up to 3.2 µg L-1 and 0.9 µg L-1 in surface and ground waters, respectively, from La Rioja region (Spain) that exceed the European Union limit (0.1 µg L−1) [20]. The dissipation and residue of metalaxyl and cymoxanil in pepper and soil were evaluated in another previous study and their residues were below the standard limits of European Union (EU) [3]. ...
Evaluating potential adverse health impacts caused by pesticides is an important parameter in human toxicity. This study focuses on the importance of subchronic toxicity assessment of cymoxanil fungicide in rats with special reference to target biochemical enzymes and histopathological changes in different tissues. In this regard, a 21-day toxicity study with repeated cymoxanil oral doses was conducted. It has been shown that low doses (0.5 mg/kg) were less effective than medium (1 mg/kg) and high (2 mg/kg) doses. Moreover, high dose dose-treated rats showed piecemeal necrosis in the liver, interstitial nephritis and tubular degeneration in the kidneys, interstitial pneumonia and type II pneumocyte hyperplasia in the lungs, gliosis, spongiosis, and malacia in the brain, and testicular edema and degeneration in the testes. Cymoxanil significantly increased AST, ALT, and ALP in serum and liver, indicating tissue necrosis and possible leakage of these enzymes into the bloodstream. Creatinine levels increased, indicating renal damage. Similarly, significant inhibition was recorded in brain acetylcholinesterase, indicating that both synaptic transmission and nerve conduction were affected. Importantly, these histopathological and biochemical alterations were dose-dependent. Taken together, our study reported interesting biochemical and histopathological alterations in different rat tissues following repeated toxicity with oral doses of cymoxanil. Our study suggests future studies on different pesticides at different concentrations that would help urge governments to create more restrictive regulations concerning these compounds’ levels.
... Meanwhile, daphnia is an aquatic Crustacean species, which is phylogenetically close to insects than zebrafish. Therefore, daphnia has been recognized as a good aquatic invertebrate model for insecticide/pesticide toxicity assessment [25,48,49]. In this study, we provided data to support this idea. ...
Pesticides are widely used to eradicate insects, weed species, and fungi in agriculture. The half-lives of some pesticides are relatively long and may have the dire potential to induce adverse effects when released into the soil, terrestrial and aquatic systems. To assess the potential adverse effects of pesticide pollution in the aquatic environment, zebrafish (Danio rerio) and Daphnia magna are two excellent animal models because of their transparent bodies, relatively short development processes, and well-established genetic information. Moreover, they are also suitable for performing high-throughput toxicity assays. In this study, we used both zebrafish larvae and water flea daphnia neonates as a model system to explore and compare the potential toxicity by monitoring locomotor activity. Tested animals were exposed to 12 various types of pesticides (three fungicides and 9 insecticides) for 24 h and their corresponding locomotor activities, in terms of distance traveled, burst movement, and rotation were quantified. By adapting principal component analysis (PCA) and hierarchical clustering analysis, we were able to minimize data complexity and compare pesticide toxicity based on locomotor activity for zebrafish and daphnia. Results showed distinct locomotor activity alteration patterns between zebrafish and daphnia towards pesticide exposure. The majority of pesticides tested in this study induced locomotor hypo-activity in daphnia neonates but triggered locomotor hyper-activity in zebrafish larvae. According to our PCA and clustering results, the toxicity for 12 pesticides was grouped into two major groups based on all locomotor activity endpoints collected from both zebrafish and daphnia. In conclusion, all pesticides resulted in swimming alterations in both animal models by either producing hypo-activity, hyperactivity, or other changes in swimming patterns. In addition, zebrafish and daphnia displayed distinct sensitivity and response against different pesticides, and the combinational analysis approach by using a phenomic approach to combine data collected from zebrafish and daphnia provided better resolution for toxicological assessment.
... Papadopoulou et al., 2016). Previous studies reported that the strong sorption of these fungicides might slow mineralization by reducing their availability to microorganisms (Herrero-Hern andez et al., 2011;Passeport et al., 2011). Furthermore, the formation of NER maintains a proportion of desorbable mobile residues (Passeport et al., 2011). ...
Pesticide inputs into surface waters may cause harmful effects on aquatic life communities and substantially contribute to environmental pollution. The present study aimed at evaluating the input pathways in the Querne/Weida catchment (central Germany) to efficiently target mitigation measures of pesticide losses. Relevant pesticide substances were measured in surface waters in agricultural and urban surroundings and in soil samples within the catchment area. Pesticides application data from farmers were analyzed. Additionally, batch tests were performed to determine sorption and degradation of relevant pesticides for site specific soil properties. Frequency of detection, number of pesticides and maximum concentrations were much higher in the surface water samples in mainly urban surroundings compared to those in agricultural surrounding. The most frequently detected substances were glyphosate, AMPA, diflufenican and tebuconazole in surface water samples and diflufenican, boscalid, tebuconazole and epoxiconazole in the topsoil samples. Glyphosate and AMPA contributed to the highest concentrations in surface water samples (max. 58 μg L⁻¹) and soil samples (max. 0.19 mg kg⁻¹). In most cases, pesticide detections in surface water and soil were not consistent with application data from farmers, indicating that urban sources may affect water quality in the catchment area substantially. However, it was observed that pesticide substances remain in the soil over a long time supported by sorption on the soil matrix. Therefore, delayed inputs into surface waters could be suspected. For the implementation of reduction measures, both urban and agricultural sources should be considered.
Novel findings of the study: pesticide detections were not consistent with application data from farmers, urban sources contributed substantially to pesticide pollution of surface waters.
... Tebuconazole is commonly used in agriculture because of its efficiency in inhibiting target fungi and its low cost (Berger et al., 2017). However, the frequent agricultural use of tebuconazole has resulted in environmental persistence in soils and water for periods of up to several months (Herrero-Hernandez et al., 2011;Papadopoulou et al., 2016;Ribas et al., 2016). Tebuconazole has toxic effects on non-target organisms (Chmist et al., 2019;Raby et al., 2019) and selects for resistance in fungal pathogens due to its site-specific targets and exposure levels (Price et al., 2015;Berger et al., 2017). ...
... Tebuconazole demonstrates medium to high lipophicity (Log Kow = 3.7) and it is easily absorbed by soil particles (Čadková et al., 2012). Nevertheless, this fungicide has relatively long persistence in soil with half-lives ranged from several weeks to more than one year depending on the soil properties and its concentrations (Herrero-Hernández et al., 2011;Muñoz-Leoz et al., 2011;Strickland et al., 2004). The non-target effects of tebuconazole on soil environment have raised several concerns. ...
Tebuconazole is a widely used fungicide that may impair soil health. Presently, limited
information is available on the bioremediation of tebuconazole-contaminated soil using
biochar as a carrier for bacteria. In this study, we firstly isolated a tebuconazoledegrading strain and identified it as Alcaligenes faecalis WZ-2. Then, we used wheat
straw-derived biochar as carrier to capture strain WZ-2 to assemble microorganismimmobilized composite. Finally, we investigated the effects of strain WZ-2 and biocharimmobilized WZ-2 on tebuconazole biodegradation, microbial enzyme activities and
community composition in the contaminated soil. Results showed that, as compared to
control, the strain WZ-2 and biochar-immobilized WZ-2 accelerated the degradation of
tebuconazole, while reducing the half-life of tebuconazole from 40.8 to 18.7 and 13.3
days in soil, respectively. However, biochar alone than control slightly retarded the
degradation of tebuconazole in soil. Though tebuconazole (10 mg/kg) negatively
affected the soil enzyme activities (urease, dehydrogenase, and invertase) and
microbiome community structure, the biochar-immobilized WZ-2 not only accelerated
the degradation of tebuconazole but also restored native soil microbial enzyme
activities and microbiome community composition. Our results suggest that a
compatible combination of bacteria with biochar is an attractive and efficient approach
for remediation of pesticide-contaminated soil and improvement of soil biological
health
... Toxicity of the pesticides may be influenced by processes like leaching, run-off, degradation, adsorption, volatilization, and plant uptake (Pose-Juan et al. 2017). These processes also influence the amount of pesticide in the soil that is bioavailable for affecting microorganisms (Jacobsen and Hjelmsø 2014), which may be altered by the application of organic residues (Herrero-Hernández et al. 2011). ...
Heterotrophic system for carbon sequestration is gaining importance in the recent decades. Carbonic anhydrase (CA) is a major enzyme involved in carbon sequestration and biomineralization process. In this paper, we evaluate the effect of pesticide on CA activity using inhibitory assay. 2,4-D, being one of the most extensively used pesticide, being deleterious to soil health, its usage should be minimized to regain the soil health. Maximum inhibitory constant (Ki) was observed for 5% 2,4-D (49.53 mM) followed by 5% glyphosate (43.92 mM). The maximum Km increase with increase in pesticide concentration by 3.05-fold was in case of glyphosate which was higher than that of 2,4-D (2.08-fold) and dichlorvos (2.38-fold). Moreover, we evaluated the carbon sequestration using CA enzyme in the soil microcosm. In the present study, we identified the negative impact of 2,4-D on carbonic anhydrase produced by Bacillus halodurans PO15. The inhibition was a mixed type and had significantly lowered the carbon reduction to about 2.38 ± 0.17% in a soil microcosm study. Based on the molecular docking, the inhibition was contributed due to weak H-bonding interaction with amino acid residues (Gly65, Gly95, Val147, Ser150 and Gly65, Ser146 and Ser150).
... SMS had thus become one of the major agriculture wastes. Except for a few examples of SMS being used for returning to the field [14], feedstuffs [15], cultivation [16], fuel and energy materials [17], the vast majority of SMS was abandoned and caused environmental pollution. Because of the abundant surface hydroxyl, carbonyl, and carboxyl groups in SMS [12], SMS could be considered as a potentially useful low-cost bio-adsorbent for dyeing wastewater treatment. ...
Dyeing wastewater is very hard to treat, and adsorption could be a good choice. Spent substrate of Pleurotus eryngii (SSPE) was first used to adsorb malachite green, safranine T and methylene blue from aqueous solutions, and the corresponding adsorption isotherm, thermodynamics and dynamics models were simulated. More than 93% of the dyes were removed with solutions with 100 mg/L of initial dye concentration, 1 g of SSPE and pH of 6.0 after adsorption for 4 h. Freundlich isotherm models fit better the adsorption data than Langmuir models. Adsorption of the dyes onto SSPE was a spontaneous exothermic process based on an adsorption thermodynamics model. SSPE could adsorb the dyes rapidly, and a second-order kinetics model fit better with the adsorption data than a pseudo first-order kinetics model. Accordingly, SSPE could be a good bio-adsorbent for the removal of malachite green, safranine T and methylene blue from the aqueous solution.
... Moreover, it is economic technique to implement in the field. A few studies conducted in the field shed the light on the suitability of spent mushroom substrate for adsorption of pollutants (Herrero-Hernández et al. 2011). ...
Due to increasing environmental pollution, there is a need for cheap and effective methods to remove pollutants from water. Mushrooms can be used as a green adsorbent in modified and natural forms to remove pollutants such as dyes and heavy metals. The use of edible mushrooms is not judicious because edible mushrooms have good nutritive and medicinal properties. Alternatively, the use of spent mushroom substrates is advised. This review discusses the potential of spent mushroom substrate as a source of immobilized mushroom mycelium, which is produced in large amounts after harvesting of mushroom fruit bodies. In laboratory conditions, Agaricus, Pleurotus, Lentinus, Calocybe and their spent mushroom substrates are efficient adsorbents allowing 70–90% of removal of pollutants. The efficiency of spent mushroom is similar to that of mushroom. Chemisorption and physisorption processes are involved in the adsorption process. Langmuir isotherms reveal the involvement of monolayer adsorption irrespective of the use of mushroom fruit bodies or spent mushroom substrate. Fourier-transform infrared (FT-IR) analysis reveals the presence of carboxyl, hydroxyl, amino group in the adsorption of pollutants, dyes and heavy metals.
... days and 6.5-24.7 days, respectively. Several previous studies showed that the half-lives of tebuconazole in agricultural soil were various from several days to one month depending on years, soil types, climate, dosage levels and commercial formulation (Dong and Hu, 2014;Herrerohernández, Andrades, Marínbenito, Sánchezmartín, & Rodríguezcruz, 2011;Patyal et al., 2013). Sun, Duan, Wang, Dong, and Gao (2013) have reported that the half-lives of tebuconazole in grape were 9.8-12.2 ...
An efficient method was developed and validated for simultaneous determination of tebuconazole, thiophanate-methyl and its metabolite carbendazim in grape and soil using QuEChERS procedure and liquid chromatography-tandem mass spectrometry. The average recoveries of the method were 83.2% - 105.4%, the limit of detection (LOD) ranged from 2.1 × 10⁻⁵ to 8.7 × 10⁻⁴ mg L⁻¹, and the limit of quantitation (LOQ) was 0.1 mg kg⁻¹. The field results showed that tebuconazole and thiophanate-methyl in soil and grape were rapidly dissipated with half-lives less than 24.7 days. The terminal residues of all analytes in grape were lower than the maximum residue limit (MRL) set by China (2 mg kg⁻¹ for tebuconazole; 3 mg kg⁻¹ for both thiophanate-methyl and carbendazim). Risk assessment showed that tebuconazole, thiophanate-methyl and its metabolite would be unlikely to cause health problems. However, carbendazim, the higher active metabolites of thiophanate-methyl, should receive more concerns.
... Its racemic form has been commercially available since 1988 and is also used now as growth factor and biocide. It is fairly persistent in soils, in particular due to its rather high lipophilic properties, with half-lives of weeks to years (DT 50 = 49-610 days) according to the soil characteristics and initial tebuconazole concentrations [11][12][13][14][15]. Nevertheless this fungicide can reach the aquatic environment mainly via surface runoff, erosion or drift from agricultural soils but also via wastewater treatment plants (WWTP). ...
The use of triazole fungicides in various fields ranging from agriculture to therapy, can cause long-term undesirable effects on different organisms from various environmental compartments and lead to resistance phenomena (even in humans) due to their extensive use and persistence. Their occurrence in various water bodies has increased and tebuconazole, in particular, is often detected, sometimes in high concentration. Only a few bacterial and fungal strains have been isolated and found to biotransform this fungicide, described as not easily biodegradable. Nevertheless, the knowledge of efficient degrading-strains and metabolites potentially formed could improve bioremediation process and global overview of risk assessment. Therefore, a broad screening of microorganisms, isolated from various environmental compartments or from commercially-available strain collections, allowed us to find six bacterial strains able to biotransform tebuconazole. The most efficient one was studied further: this environmental strain Bacillus sp. 3B6 biotransforms the fungicide enantioselectively (ee = 18%) into two hydroxylated metabolites, one of them being transformed in its turn to alkene by a biotic dehydration reaction. This original enantioselective pathway shows that racemic pesticides should be treated by the environmental risk assessment authorities as a mixture of two compounds because persistence, biodegradation, bioaccumulation and toxicity often show chiral dependence.
... The fungicide tebuconazole belongs to the chemical group of triazoles and is used in agriculture to control fungi (Andrei 2017). Tebuconazole formulated fungicides are persistent in the environment (Herrero-Hernández et al. 2011), and may cause adverse effects on aquatic organisms (Sancho et al. 2016). Tebuconazole's adsorption coefficient is 2500 mL/g, the half-life is 403 days in the soil, and it has the potential to be transported in water associated with sediment because of its high affinity with organic matter. ...
Brazil is the largest consumer of pesticides in the world. However, knowledge on how these pesticides affect wildlife is scarce. Among the vertebrates, amphibians are particularly important in research to assess the impact of pesticides because of the correlation between pesticide and the decline of these species. This study aimed to evaluate the acute and chronic toxicity of commercial formulations of pesticides, i.e., atrazine (herbicide), cypermethrin (insecticide), and tebuconazole (fungicide) in Physalaemus cuvieri tadpoles. Eggs were collected in nature and cultivated under controlled conditions in the laboratory. Toxicity tests were carried out under standard conditions to determine the lethal concentration (LC50) after 96 h of exposure and to determine the effect of sublethal concentrations after 7 days. In addition, we performed swimming activity tests on tadpoles exposed to sublethal concentrations. The lethal concentration (LC50) was 19.69 mg/L for atrazine, 0.24 mg/L for cypermethrin and 0.98 mg/L for tebuconazole. In the acute test, atrazine showed lower toxicity than cypermethrin and tebuconazole for P. cuvieri. Swimming activity was affected at sublethal doses of atrazine and cypermethrin, but was not after exposure to tebuconazole. Cypermethrin was the insecticide that most altered the swimming activity of the individuals tested. The risk evaluation analysis indicated risks for tadpoles exposed to three tested pesticides, specially cypermethrin.
... The determined half-lives of isoproturon and diuron were comparable to previous studies. 13 −15 In previous studies tebuconazole showed biphasic degradation kinetics, 17 and a half-life of 800 days 18 and also for propiconazole half-lives of 200 days to more than a year have been determined previously, 19,20 while the two triazoles showed no degradation within the time frame of the present study. ...
Biocides are common additives in building materials. In-can and film preservatives in polymer-resin render and paint, as well as wood preservatives are used to protect facade materials from microbial spoilage. Biocides leach from the facade material with driving rain, leading to highly polluted runoff water (up to several mg L⁻¹ biocides) being infiltrated into the soil surrounding houses. In the present study the degradation rates in soil of eleven biocides used for the protection of building materials were determined in laboratory microcosms. The results show that some biocides are degraded rapidly in soil (e.g. isothiazolinones: T1/2 < 10 d) while others displayed higher persistence (e.g. terbutryn, triazoles: T1/2 >> 120 d). In addition, mass balances of terbutryn and octylisothiazolinone were determined, including 9 (terbutryn) and 7 (octylisothiazolinone) degradation products, respectively. The terbutryn mass balance could be closed over the entire study period of 120 d and showed that relative persistent metabolites were formed, while the mass balances for octylisothiazolinone could not be closed. Octylisothiazolinone degradation products did not accumulate over time suggesting that the missing fraction was mineralized. Microtox-tests revealed that degradation products were less toxic towards the bacterium Aliivibrio fischeri than their parent compounds. Rain is mobilizing these biocides from the facades and transports them to the surrounding soils; thus, rainfall events control how often new input to the soil occurs. Time intervals between rainfall events in Northern Europe are shorter than degradation half-lives even for many rapidly degraded biocides. Consequently, residues of some biocides are likely to be continuously present due to repeated input and most biocides can be considered as “pseudo-persistent”-contaminants in this context. This was verified by (sub)urban soil screening, where concentrations of up to 0.1 µg g⁻¹ were detected for parent compounds as well as terbutryn degradation products in soils below biocide treated facades.
... The impact of pesticides on a soil microbial community depends on their toxicity, which determines hazard, and on their fate in the soil, which is governed by several processes such as adsorption, leaching, run-off, degradation, volatilization, plant uptake, etc. These processes control the amount of pesticide in the soil that is bioavailable for affecting microorganisms (Jacobsen and Hjelmsø, 2014), and they could be modified by the application of organic residues (Herrero-Hernández et al., 2011). ...
The effect of organic amendments and pesticides on a soil microbial community has garnered considerable interest due to the involvement of microorganisms in numerous soil conservation and maintenance reactions. The aim of this work was to assess the influence on a soil microbial community of the simultaneous application of the herbicide triasulfuron at three doses (2, 10, and 50 mg kg-1), with an organic amendment [sewage sludge (SS) or green compost (GC)]. Dissipation kinetics, soil microbial biomass, dehydrogenase activity (DHA) and respiration, and the profile of phospholipid fatty acids (PLFAs) extracted from the soil, were determined in unamended (S) soil and amended (S+SS and S+GC) ones. Triasulfuron dissipation followed the single first-order kinetics model. Half-life (DT50) values were higher in the amended soils than in the unamended one for the 10 and 50 mg kg-1 doses. The dissipation rates were lower in the S+GC soil for the three herbicide doses applied. In general, soil biomass, DHA and respiration values increased in SS- and GC-amended soils compared to the unamended one. DHA values decreased (S and S+SS) or increased (S+GC) with the incubation time of soil with herbicide at the different doses applied. Respiration values increased with the herbicide doses applied and decreased with the incubation time, although maximum values were obtained for soils treated with the highest dose after 70 days of incubation. PLFA analysis indicated different effects of triasulfuron on the soil microbial community structure depending on the organic amendments. While the increasing triasulfuron doses resulted in deeper alterations in the S soil, the time after triasulfuron application was the most important variation in the S+SS and S+GC soils. The overall results indicate that the soil amendment has an effect on herbicide dissipation rate and the soil microbial community. Initially, a high dose of triasulfuron had detrimental effects on the soil microbial community, which is important in the case of the long-term use of this compound.
... These agricultural wastes have shown good properties for heavy metals sorption (Chen et al. 2005;Tapia et al. 2010). However, Herrero-Hernández et al. (2011, 2012 reported mobilization of heavy metals after SMS applications to soil. The behavior of SMS is not always predictable because of the heterogeneity of its components (Paredes et al. 2009). ...
The use of agricultural wastes as biosorbents is gaining importance in bioremediation of heavy metal-polluted water and soils, due to their effectiveness and low cost. This work assesses the Cd, Pb and Cu adsorption capacity of the raw materials used in the production of substrates for mushroom production (Agaricus bisporus and Pleurotus ostreatus) and the spent mushroom composted (SMC), based on the functional groups of their organic carbon. The raw materials studied included agricultural wastes (wheat straw, wheat and rice poultry litter, grape pomace) and inorganic substances (gypsum and calcareous sand). Organic carbon from wastes and their composting products were characterized by CP-MAS ¹³C NMR. Langmuir adsorption isotherms of metals were plotted for each raw material, composting step, spent A. bisporus and P. ostreatus substrates and the final SMC. The maximum adsorption capacities of SMC were 40.43, 15.16 and 36.2 mg g⁻¹ for Cd, Pb and Cu, respectively. The composting process modified the adsorption properties of raw materials because of the enhanced adsorption of Cd and Cu and decreased adsorption capacity of Pb. CP-MAS ¹³C NMR and potentiometric titration were used to identify the functional groups of the organic carbon responsible for the metal adsorption. The content of cellulose was correlated with Pb adsorption (p < 0.001), alkyl and carboxyl carbon with Cd adsorption (p < 0.001), and N-alkyl (p < 0.001) and carboxyl (p < 0.010) groups with Cu adsorption. These results are valuable to develop new biosorbents based on agricultural wastes and demonstrate the high potential of SMC to adsorb heavy metals from polluted environments.
... Literature data also suggest that dehydrogenases Kucharski and Wyszkowska 2008;Bacmaga et al. 2014Bacmaga et al. , 2015a is the most susceptible parameter to pesticides application. Though Herrero- Hernández et al. (2011) reported the stimulatory effect of tebuconazole on dehydrogenase activity under laboratory condition in unamended and amended soil, but Muñoz-Leoz et al. (2011) reported the decreased dehydrogenase activity in tebuconazole-treated soil, particularly at higher concentrations. Bending et al. (2007) reported that tebconazole application to soil had mixed effect on the dehydrogenase activity, and the effect was dependent on Environ Earth Sci (2016) 75:558 ...
Field experiments in peanut (Arachis hypogaea L.) soil ecosystem were conducted during the summer seasons (February–June) of the year 2013 and 2014 in black clay soil treated with tebuconazole at field rate (FR), 2-times FR (2FR) and 10-times FR (10FR) as foliar spray to determine the impact of tebuconazole on soil microbial properties and enzymatic activities. Tebuconazole application at FR and 2FR resulted in a short-lived and transitory toxic effect on soil microbial properties and enzymatic activities. The duration of this disturbance was slightly longer at 10FR. Incorporation of tebuconazole in soil resulted in stimulating the soil microbial activity as evidenced by increased ammonification and nitrification rates and increased soil microbial biomass at later stage. However, it was more toxic to soil ergosterol which is the indicator of the presence of viable fungi. Soil enzymatic activities like fluorescein diacetate-hydrolyzing activity, urease, phosphatase and aryl sulfatase are either unaffected or shortly inhibited and then recovered. However, dehydrogenase and nitrate reductase activity decreased more drastically and can be used as valuable indicator to assess the impact of tebuconazole application on soil health. The results indicated that instead of single assays, a broad spectrum analysis of soil microbial and enzymatic activities gives a better insight about the impacts of pesticide on soil health. From this study, it is also concluded that the application of tebuconazole at 10FR had adverse effects on the microbial variables and the effect on long-term application should be studied further.
... The literature search revealed that studies reporting TCZ dissipation often ignored the occurrence of potential TPs and mainly followed targeted analytical approaches (Sehnem et al., 2010;Woo et al., 2010). It is noteworthy that non-target approaches resulted in the detection of previously unknown TPs in studies looking at the degradation of TCZ in bacterial or fungal cultures (Obanda and Shupe, 2009), during photolysis (Calza et al., 2002), in field studies (Herrero-Hernandez et al., 2011;Potter et al., 2005), in microcosm studies (Strickland et al., 2004;White et al., 2010) and in fruit (Schermerhorn et al., 2005). Additional information was found in regulatory documents mainly citing unpublished or confidential studies reporting TPs in soil and crops, partially based on MS and NMR spectroscopy (EFSA, 2008;FAO, 1994;U.S. EPA, 1990). ...
... diferentes enmiendas orgánicas en la disipación de pesticidas (Dolaptsoglou et al., 2009;Herrero-Hernández et al., 2011). ...
The changes of physicochemical and biochemical parameters of a silty loam (S1) and sandy loam (S2) vineyard soils added with spent mushroom substrate (SMS) or SMS composted with ophite (OF) as rock dust (SMS + OF) were studied. Two doses of SMS or SMS + OF (25 and 100 Mg ha-1) were applied for two consecutive years (2020-2021) and changes of soil physicochemical parameters, and dehydrogenase activity (DHA), respiration (RES), microbial biomass (BIO), and the phospholipid fatty acids (PLFAs) profile were assayed on a temporal basis. The results showed an increase in soil organic carbon (OC) content, total and mineralised N, P, and K, especially when the highest SMS dose was applied to soils. Repeated application caused OC content over time up to 2.3 times higher than initial content in the silty loam soil. This increase was not observed in sandy soil, possibly due to a higher bioavailability of OC, as indicated by the evolution of extractable humic acid/fulvic acid pools. In both soils, all biochemical parameters increased after amendment, being favoured both by the OC and by the presence of. Significant positive correlations were found between DHA, RES and BIO, and OC content especially in the first part and then levelled off after the second dose application. Total bacterial or fungal PLFAs patterns reflected the variation of BIO by SMS application. The higher growth of fungi vs. bacterial community in amended soils was recorded after the first SMS application, although the opposite effect occurred after the second application, with similar results in both soils. The findings indicate that the application of SMS or SMS + OF in vineyard soils could be an appropriate agronomic management practice for maintaining soil sustainability, although doses and application times of these amendments should first be evaluated depending on soil texture.
The production of wine dates to ancient civilization and has heavily influenced different landscapes around the globe. Nowadays, wine is still an important sector in terms of land use and income source in many countries, more specifically in the European Mediterranean region. However, to control pests and regulate wine growth, the extensive use of pesticides is common. The effects and persistence of agrochemicals in the environment is well known and defined in scientific literature as well as the environmental and human health risks of these compounds. The purpose of this review was to do a state of art of worldwide production of academic literature using bibliometric principles and analysis to identify thematic areas of this type of agriculture, and its challenges in a changing world. For this review, the focus is on current practices to see what may evolve for more sustainable viticulture. It was found that the three main producers of wine, i.e., Spain, France, and Italy, are also three top producers of scientific literature on this topic. The use of bibliometric methodologies defined the main thematic areas on this subject as follows: soil–plant transfer of agrochemicals, heavy metal accumulation in vineyard soils, management practices in viticulture, water pollution transport, effects of viticulture on the living part of soil, sustainable alternatives to pesticides. We found that Spain, France, and Italy work the most on developing sustainable alternatives for agricultural practices; however, sustainable alternatives and practices were also the least developed thematic in general.
Zoxamide is a benzamide fungicide applied to control diseases caused by oomycete fungi. Fertilizers are important agricultural supplies to adjust soil properties and increase nutrition. To investigate the impact of zoxamide and seven fertilizers urea, phosphate fertilizer, potash fertilizer, compound fertilizer, organic fertilizer, vermicompost and soya bean cakes on the soil environment, the enantioselective dissipation characteristics of zoxamide, soil enzyme activities, pH and N, P nutrition changes were comprehensively analyzed in our present study. The enantioseparation method was successfully validated to quantify the zoxamide enantiomers in soil by HPLC using Chiral NQ (2)-RH column. Our results demonstrated that the R-(−)- and S-(+)-zoxamide half dissipated in the range of 10.88–17.81 and 8.05–14.41 days, respectively. S-(+)-zoxamide disappeared faster in soil. The vermicompost accelerated the dissipation rate of S-(+)-zoxamide, while urea, phosphate, organic and vermicompost fertilizer increased the dissipation selectivity. Zoxamide and fertilizers other than urea caused soil acidification during 80 days. Zoxamide was beneficial to soil catalase, instead inhibited soil urease, dehydrogenase activities and available phosphorus content. No significant effects on sucrase activity and available nitrogen content were found by zoxamide. Vermicompost and soya bean cakes had lasting and outstanding performance in efficiently improving soil enzyme activity and N, P nutrition. The comprehensive understanding of the ecological impact induced by chiral pesticide enantiomers and fertilizers on soil is vital to ensure the sustainable development and safety of agricultural production.
Agricultural development and the sustainability of agrosystems are two topics of great current interest. The typical model of intensive or conventional agriculture provides highly productive agrosystems, but at an important environmental cost. Therefore, new cropping systems, soil management and/or agricultural practices are being put in place to ensure sustainable agricultural production and reduce the environmental impact, as a challenge facing agriculture both now and in the future. However, the use of pesticides remains necessary even in this new approach to agricultural management, as well as tracking their fate in these systems because it has generally been studied under conventional practices. Some laboratory-scale studies have reported the effects of these practices, but few studies have been conducted under field conditions. Accordingly, this chapter conducts a review of current studies including pesticide persistence, dissipation and mobility in soils according to conservation agricultural practices, such as the soil application of organic amendments, conservation tillage systems or crop rotation. The chapter also includes a review of existing models to simulate pesticide behaviour under these management practices. Finally, a summary with research gaps and recommendations is proposed for the future development of modelling under conservation practices as tools for predicting possible long-term soil and/or water pollution.
Tebuconazole is one of the most commonly used active substances from the group of triazoles, that exhibits high efficacy in plant protection against fungal diseases. It’s too frequent use may, however, pose risk to soil ecosystems, leading to changes in their biological diversity. This study was aimed at evaluating the effect of tebuconazole on population numbers, diversity, and structure of bacterial communities, and on the enzymatic activity of soil. Tebuconazole was introduced into the soil (sandy loam with pH 7.0) in the following doses in mg kg⁻¹ DM (dry matter) of soil: 0.00 (C), 0.02 (O), and 10.0 (T). It caused changes in the population numbers of diversity of bacteria as well as in the biochemical activity of soil. It stimulated the proliferation of organotrophic bacteria and inhibited that of actinobacteria. The r-strategists were found to predominate among both the organotrophs and actinobacteria in the soil with tebuconazole addition. The amplicon sequencing of the 16S encoding gene (SSU rRNA) demonstrated tebuconazole to elicit changes in the structure of bacterial communities. In all soil samples, the prevailing taxon at the Phylum level turned out to be Proteobacteria, followed by Firmicutes and Actinobacteria, whereas the lowest counts were noted for Verrucomicrobia. The relative abundance of the bacteria at the Phylum level decreased in the soil under the influence of tebuconazole. The most sensitive to the effect of tebuconazole applied in a dose of 10.0 mg kg⁻¹ turned out to be Acidobacteria, whereas the most resistant were Verrucomicrobia. The predominating taxon at the class level was Alphaproteobacteria, followed by Bacilli. Tebuconazole ensured favorable conditions for the development of bacteria from Kaistobacter and Bacillus genera as their OTUs were the highest in the soil treated with tebuconazole at 10.0 mg kg⁻¹. In turn, Phenylobacterium and Rhodoplanes were sensitive to soil treatment with tebuconazole at doses of 0.02 mg kg⁻¹ and 10.0 mg kg⁻¹. Tebuconazole proved to be a strong inhibitor of urease and catalase activities, while in turn it enhanced activities of dehydrogenases, acid phosphatase, alkaline phosphatase, and arylsulfatase.
The accumulation of agronomic wastes has caused several environmental problems, such as air and soil contamination, and insect and pathogen proliferation, among others. To mitigate this, studies have evaluated the use of these wastes as substrates for the cultivation of Pleurotus mushrooms, a low-cost/nutritionally important crop. This study aimed to evaluate the use of corn stubble and rice straw as substrates for the in vitro production of oyster mushrooms (Pleurotus ostreatus Jacq.) and the productive characterization (biological efficiency, production rate, earliness, daily productive capacity) of four isolated strains. The strains PO/A01, PO/A02, PO/A03, and PO/A04 were grown in Potato-Dextrose-Agar medium until complete colonization. The experiment was evaluated under a completely randomized design with 6 replications. Subsequently, the corn stubble and rice straw were disinfected, inoculated, bagged, incubated, and subjected to induction-fructification. The productive period ended after three harvests. At this stage, the experiment was conducted under a completely randomized design with a 4 × 2 factorial arrangement with 8 replications. The P. ostreatus strains inoculated in the corn stubble, compared to rice straw, showed 93.93% biological efficiency and a 2.07% production rate, representing increases of 30% and 50%, respectively. The strains PO/A03 and PO/A04 showed higher biological efficiency and organic matter loss. The PO/A02 strain showed greater earliness, with approximately 10 days to harvest. This study concluded that the isolated strains of P. ostreatus allow for the efficient use of corn stubble and rice straw, and can contribute to the management of agronomic wastes.
Graphic abstract
The use of reclaimed water in crop irrigation helps to mitigate water shortage. The fertilization of arable soils with sewage sludge, biosolids, or livestock manure reduces extensive application of synthetic fertilizers. However, both practices lead to the introduction of pharmaceutical active compounds (PhACs) in arable soil, known to host a wide range of living organisms, including microorganisms which are supporting numerous ecosystem services. In soils, the fate of PhACs is governed by different abiotic and biotic processes. Among them, soil sorption and microbial transformation are the most important ones and determine the fate, occurrence, and dispersion of PhACs into the different compartments of the environment. The presence of PhACs in soils can compromise the abundance, diversity, and activity of the soil microbial community which is one of the key players in a range of soil ecosystem services. This chapter reviews the current knowledge of the effects of PhACs, commonly found in wastewater effluents and derived organic fertilizers, on the soil microbial community.
Addition of organic residues to soil is a current farming practice but it is not considered in the modelling studies for pesticide risk assessment at regulatory level despite its potential impact on the pesticide dynamics in soil. Thus, the objective of this work was to examine and to compare the ability of PRZM and MACRO pesticide fate models to simulate soil water content, and bromide (Br-, tracer), chlorotoluron and flufenacet concentrations in the soil profiles (0-100 cm) of one agricultural soil, unamended (control soil, S), amended with spent mushroom substrate (S + SMS) or amended with green compost (S + GC). Based on a two-year field-scale dataset, the models were first calibrated against measurements of water and solutes contents in the soil profiles (first year) and then tested without any further model calibration by comparison with the field observations of the second year. In general, the performance of MACRO to simulate the whole dataset in the three soil treatments was higher than that of PRZM. MACRO simulated satisfactorily the water dynamics along the soil profiles whereas it was poorly described by the capacity model PRZM. Both models predicted very well the Br- mobility in control and amended soils after dispersion parameters were fitted to observations. No calibration was necessary to reproduce correctly herbicides vertical distribution in the control soil profile. In the amended soils, MACRO simulations were highly correlated to the observed vertical distribution of flufenacet and chlorotoluron, but calibration of the Kd of chlorotoluron was needed. On the contrary, modelling with PRZM required calibration of Kd and DT50 of both herbicides to obtain an acceptable agreement between observations and predictions in the amended soils. Kd and DT50 calibration was based on the initial dissolved organic carbon contents (DOC) of amended soils. It allowed to take into account the processes that decrease the herbicides sorption on the soil and enhance their bioavailability, but that are not described in PRZM and MACRO (such as the formation of herbicide-DOC mobile complexes). This work showed that models such as PRZM and MACRO are able to simulate the fate of pesticides in amended soils. However, before using these models as predictive tools in large amended soil conditions, and especially in the regulatory context, further modelling studies should focus on other pedoclimatic-pesticides-organic residues combinations, and on longer periods.
Pesticide contamination is one of the most serious threats for agricultural soils. Excessive pesticide levels in soil can exert negative effects on soil-dwelling organisms by decreasing their bioavailability and, consequently, lowering soil quality. This study aimed to evaluate the effect of a mixture of spiroxamine, tebuconazole, and triadimenol (S + Te + Tr) on the biological activity of soil determined based on the proliferation of microorganisms and their diversity, enzymatic activity of soil, and resistance of Triticum aestivum L. A pot experiment was performed on sandy loam (pH 7.0) treated with four doses of the tested active ingredients: 0.000, 0.092, 2.76, 13.80, and 27.60 mg kg−1. Soil without the fungicide served as the control sample. The tested fungicide induced changes in the biological activity of soil. When administered to the soil in the highest dose (27.60 mg kg−1 DM of soil), it inhibited its biological activity. It significantly inhibited the proliferation of organotrophs, actinomycetes, and fungi, but still the most susceptible to its effects turned out to be fungi. Fungicide dose of 27.60 mg kg−1 decreased counts of organotrophic bacteria, actinomycetes, and fungi by on average 0.009 log, 0.100 log, and 0.282 log, respectively, compared to the control sample. Administration of the S + Te + Tr mixture to soil decreased also values of colony development index (CD) determined for all tested groups of microorganisms. Values of the ecophysiological diversity index (EP) decreased in the case of organotrophs and actimomycetes and increased in the case of fungi. The S + Te + Tr mixture inhibited activities of dehydrogenases, urease, and acid phosphatase. Significant changes were also reported in the growth of spring wheat. The resistance index (RS) calculated based on plant yield demonstrated spring wheat to be very susceptible to the tested preparation administered to soil in doses of 13.80 and 27.60 mg kg−1.
Soil is a non-renewable resource, and its degradation compromises human health, natural ecosystems, and even the climate. The application of organic amendments and herbicides is commonplace in agriculture, and their impact on soil fertility needs to be evaluated. Therefore, the objective was to evaluate the effect on soil microbial activity and structure of amendments, sewage sludge (SS) and green compost (GC), and the rate of herbicide pethoxamid applied (2, 10 and 50 mg kg ⁻¹ ). Herbicide dissipation kinetics, soil dehydrogenase activity (DHA) and the profile of phospholipid-derived fatty acids (PLFAs) extracted from the soil have been determined in unamended (S) and amended (S + SS and S + GC) soils. The dissipation curves of pethoxamid applied at the three rates closely fitted a single first order kinetics model in all the soils. The dissipation rate decreased with the rate applied in the order 2 mg kg ⁻¹ > 10 mg kg ⁻¹ > 50 mg kg ⁻¹ in unamended and amended soils. However, the half-life or time required for 50% dissipation (DT 50 ) of pethoxamid was not significantly different in unamended and amended soils when applied at 2 and 10 mg kg ⁻¹ , but it was lower in the amended soils than in the unamended one when the herbicide was applied at the highest rate. The highest DHA mean values were obtained in S + GC treated with pethoxamid at 2, 10 and 50 mg kg ⁻¹ ; however, DHA was lower in S + SS than in S. Peak DHA values were observed in S and S + GC soils treated with pethoxamid at 2 mg kg ⁻¹ at 15 days of incubation, and in S, S + GC and S + SS treated with the herbicide at 10 and 50 mg kg ⁻¹ at 35 days of incubation. These peak DHA values are close to 50% of herbicide dissipation. A statistical analysis of the PLFA results has revealed significant effects for sampling time in all the soils, for the pethoxamid rate, and for the interaction between time and pethoxamid rate only in S + GC and S + SS. The application of organic 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 on the soil microbial community.
Phenthoate is a widely used organothiophosphate insecticide during
cultivation of various crops such as red pepper, green onion, cucumber, and
tomato. This study investigated the dissipation characteristics of phenthoate in
grain and straw of minor crop millet after spraying phenthoate 47.5%
emulsifiable concentrate (EC) formulation. For field trial, the pesticide was
treated on 4 plots (Plot1; 40/30 days, Plot 2; 30/21 days, Plot 3; 21/14 days
and Plot 4; 14/7 days before harvest) by three replicates. The residue of the
pesticide was analyzed by LC-MS/MS and method limit of quantitation
(MLOQ) were 0.01 mg/kg. The linearity (r2) of calibration curve was ≥ 0.999
at the calibration range of 0.005-0.5 grade g/mL. After harvest, maximum
phenthoate residues in plot 1 were 0.02 mg/kg in both of grain and straw. In
plot 2 the residues were 0.15 mg/kg (grain) and 0.04 mg/kg (straw), while the
residue in plot 3 were 0.61 and 0.18 mg/kg in grain and straw, respectively. In
plot 4, 0.72 mg/kg (grain) and 0.38 mg/kg (straw) of residue were observed.
These results will be used for establishing pre-harvest interval (PHI) of
phenthoate during cultivation of millet. The dissipation pattern and half-life of
phenthoate in soil was also evaluated in laboratory condition. Ten grams of
soils which were fortified with phenthoate standard solution at the
concentration of 0.75 mg/kg were incubated at 25℃ in the dark condition.
The soil samples were collected at 0 hr, 2 hr, 6 hr, 12 hr, 24 hr (1 days), 48 hr
(2 days), 72 hr (3 days), 120 hr (5 days), 168 hr (7 days), 336 hr (14 days), and
672 hr (28 days) after treatment. The residue of the pesticide was analyzed by
GC-μECD (Agilent-7890). The MLOQ was 0.005 mg/kg. The linearity (r2) of
calibration curve was ≥ 0.999 at the calibration range of 0.005-0.5 μg/mL. The
phenthoate was dissipated rapidly in soil with the dissipation curve of y=556.09e-0.009x (r2=0.9796) while the 77.0 hours (3.2 days) of 1º-half-life was
determined.
Cette étude s'est portée sur l'évaluation du pouvoir épurateur de dispositifs rustiques de filtration des eaux de drainage, mis en place dans le cadre de la Zone Atelier Moselle. Actuellement, quatre dispositifs ont été installés en Lorraine (Broussey-en-Woëvre (57), Jallaucourt (55), Manoncourt-sur-Seille (54) et Ollainville (88), France). Cinq pesticides (2 herbicides : isoproturon et napropamide ; 3 fongicides : boscalid, prochloraze et tébuconazole) ont été sélectionnés en fonction de leur fréquence d'application et des quantités utilisées sur les parcelles agricoles alimentant les dispositifs et suivant des paramètres physico-chimiques variés. Quatre substrats, prélevés au sein des dispositifs, ont été utilisés (sols (2), sédiment et paille). La minéralisation du carbone organique a été suivie par mesure du CO2 dégagé. Une diminution de la minéralisation a été observée pour deux modalités par rapport à des témoins non traités. Les cinétiques de dégradation des pesticides en mélange ont été suivies en milieu anoxique et à des concentrations proches de celles observées dans les eaux de drainage (300 ng.l-1) durant 45 jours en conditions de laboratoire. L'extraction des molécules a été réalisée par ASE pressurisé et dosé par UHPLC. Au terme de 45 jours d'incubation, les teneurs en résidus de pesticides extractibles ont montré aucune diminution significative pour l'ensemble des molécules et des modalités. Dans le but de préciser cette étude, des isothermes d'adsorption et de désorption devront être réalisées afin évaluer le pouvoir de sorption des dispositifs ainsi que des cinétiques de dégradation à des teneurs en eau plus faible afin évaluer le pouvoir épurateur en conditions de ressuyage.
Herbicides are essential in agricultural systems for maintaining crop yields, as weeds compromise grain production. Furthermore, the application of organic amendments to soil is an increasingly frequent agricultural practice for avoiding irreversible soil degradation. However, this practice could modify the behaviour of the herbicides applied, with implications for their absorption by weeds. This study evaluated the dissipation, persistence and mobility of the herbicides triasulfuron and prosulfocarb in a sandy clay loam soil unamended and amended with green compost (GC) in a field experiment using single or combined commercial formulations of both herbicides. The study was carried out in experimental plots (eight treatments × three replicates) corresponding to unamended soil and soil amended with GC, untreated and treated with the herbicide formulations Logran®, Auros® and Auros Plus® over 100 days. The half-life (DT50) of triasulfuron applied individually was 19.4 days, and increased in the GC-amended soil (46.7 days) due to its higher adsorption by this soil, although non-significant differences between DT50 values were found when it was applied in combination with prosulfocarb. Prosulfocarb dissipated faster than triasulfuron under all the conditions assayed, but non-significant differences were observed for the different treatments. The analysis of the herbicides at different soil depths (0-50 cm) after their application confirmed the leaching of both herbicides to deeper soil layers under all conditions, although larger amounts of residues were found in the 0-10 and 10-20 cm layers. The application of GC to the soil increased the persistence of both herbicides, and prevented the rapid leaching of triasulfuron in the soil, but the leaching of prosulfocarb was not inhibited. The influence of single or combined formulations was observed for triasulfuron, but not for prosulfocarb. The results obtained highlight the interest of obtaining field data to design rational joint applications of GC and herbicides to prevent the possible decrease in their effectiveness for weeds or the risk of water contamination.
This chapter provides a spectrum of the research investigations on the use of spent mushroom substrate (SMS). It outlines characteristics of spent substrate, and presents the following uses for spent substrate: bioremediation, crop production, reuse in the cultivation of mushrooms, food for animals and fish, and pest management. Bioremediation is the use of living organisms such as bacteria, fungi, or green plants, to remove or neutralize unwanted contaminants in air, soil, or water. SMS has been assessed as a partial solution to environmental contaminations. Mushrooms are cultivated on organic substrates, naturally suitable for agricultural crops. Spent substrate of Agaricus bisporus has been explored for the production of various vegetable crops, including asparagus, beetroot, cauliflower, cabbage, capsicums, celery, cucumber, lettuce, green gram, mustard, onion, potato, radish, snap bean, spinach, sugar beet, tomato, and zucchini. Mushrooms are proteinaceous and the substrate formulations may include cereal straws and various grains that are components of animal diets.
Citrus fruit-packaging plants (FPP) produce large wastewater volumes with high loads of fungicides like ortho-phenylphenol (OPP) and imazalil (IMZ). No methods are in place for the treatment of those effluents and biobeds appear as a viable alternative. We employed a column study to investigate the potential of spent mushroom substrate (SMS) of Pleurotus ostreatus, either alone or in mixture with straw and soil plus a mixture of straw /soil to retain and dissipate IMZ and OPP. The role of P. ostreatus on fungicides dissipation was also investigated by studying in parallel the performance of fresh mushroom substrate of P. ostreatus (FMS) and measuring lignolytic enzymatic activity in the leachates. All substrates effectively reduced the leaching of OPP and IMZ which corresponded to 0.014-1.1% and 0.120-0.420% of their initial amounts respectively. Mass balance analysis revealed that FMS and SMS/Straw/Soil (50/25/25 by vol) offered the most efficient removal of OPP and IMZ from wastewaters respectively. Regardless of the substrate, OPP was restricted in the top 0-20cm of the columns and was bioavailable (extractable with water), compared to IMZ which was less bioavailable (extractable with acetonitrile) but diffused at deeper layers (20-50, 50-80cm) in the SMS- and Straw/Soil-columns. PLFAs showed that fungal abundance was significantly lower in the top layer of all substrates from where the highest pesticide amounts were recovered suggesting an inhibitory effect of fungicides on total fungi in the substrates tested. Our data suggest that biobeds packed with SMS-rich substrates could ensure the efficient removal of IMZ and OPP from wastewaters of citrus FPP.
The application of different organic residues as a soil amendment is an agricultural practice used to improve soil fertility by increasing the soil organic matter (OM). However, the OM from these residues can influence the behavior of pesticides applied jointly to the soil. Modification of the pesticide bioavailability in soils is of special interest since it can affect the activity and/or functioning of soil microbial community. Accordingly, the dissipation kinetics of mesotrione in unamended soil (S) and soils amended with sewage sludge (S+SS), green compost (S+C) and commercial pellets (S+P) and its possible effects on the soil microbial communities were studied. Soil biological parameters were determined as indicators of the soil microbial activity, functioning and structure: microbial biomass, dehydrogenase activity, respiration, and analysis of the phospholipid fatty acid (PLFA) profile extracted from the soil. Dissipation was more rapid in unamended soil than in amended soils and half-life (DT50) values followed the order S+SS > S+C % S+P > S. The biomass values increased in the amended soils with the exception of the P-amended soil. However, mesotrione had different effects on this parameter depending on the soil treatment. In general, dehydrogenase activity was stimulated by the addition of the amendment and herbicide to soil. Initially, respiration was higher in the unamended soil (control and treated soils) than the amended soils and mesotrione did not have any effect on this parameter. PLFAs analysis indicated that the overall structure of active microbial communities as well as the relative abundance of certain groups of microorganisms clearly changed according to the type of amendment and the incubation time, but remained unaffected by the application of mesotrione.
An increase of organic waste coming from different humans and productive activities is a continuous concern, and their application in soil is proposed many times as a solution to disposal problem. In agricultural soil, this practice is actually more popular because of its contribution as a fertilizer and soil enhancement. Recently, increased interest has been focused on assessing the influence of organic waste added to the soil related to pesticides behavior. The studies carried out show that addition of organic matter and nutrient mainly can affect the adsorption, movement, and biodegradation of pesticides. This review shows the factors involved, trend, and result obtained with pesticide behavior in soil amendment. Contradictory trends are reported in the literature on the pesticides' fate. These are mainly because soil type differences, pesticide characteristics, and source amendment are difficult to organize in a tendency pattern, and can significantly complicate the understanding of pesticides fate.
Tebuconazole is a widely used fungicide. The formation of by-products on irradiated titanium dioxide as a photocatalyst was evaluated. Several species derived from tebuconazole degradation were identified and characterized by HPLC/MS(n). A pattern of reactions accounting for the observed intermediates is proposed. Different parallel pathways are operating (and through these pathways the transformation of the molecule proceeds), leading to a wide range of intermediate compounds. All these molecules are more hydrophylic than tebuconazole. The main steps involved are (1) the hydroxylation of the molecule with the formation of three species having [M + H](+) 324; the hydroxylation occurs on the C-1 carbon and on the aromatic ring in the two ortho-positions; (2) the cleavage of a C--C bond with the release of the tert-butyl moiety and the formation of a species having m/z 250; analogously to step 1, also on this species a further hydroxylation reaction occurs; (3) through the loss of the triazole moiety with the formation of a structure with m/z 257.
Adsorption-desorption studies of metalaxyl in fifteen agricultural soil samples from Southern Portugal and Spain were performed following a batch equilibration method. Very high sorption was observed on a clay soil of high content in altered illite, but, when this soil was excluded from regression analysis, organic matter (OM) was the most important single soil property affecting sorption at low concentrations of metalaxyl. At higher concentrations, no correlation was observed with any soil property. The relevance of OM on sorption was also corroborated by the increase in sorption coefficients when soil OM was increased artificially by the addition of an organic amendment. Sorption studies with the colloidal fraction of selected soils also revealed the importance of mineral surfaces in metalaxyl sorption. Sorption of metalaxyl in most of the soil samples was hysteretic. Selected soil samples were incubated in the dark, sampled periodically and extracted for their fungicide content. Metalaxyl half-lives increased with sorption and OM content of the soil, and were specially high in the amended soil. Leaching studies in hand-packed columns under saturated/unsaturated flow conditions showed an inverse relation between leaching and sorption. Recoveries from the soil columns were close to 80% of the metalaxyl applied, except for the soil which OM was artificially increased, in which recovery was lower and this has been attributed to the much higher irreversibility of metalaxyl sorption in the amended soil.
The fungicide tebuconazole is widely used to control soil-borne and foliar diseases in peanuts and other crops. No published data are currently available on the extent and rate at which this compound degrades in soil. Unpublished data summarized in registration documents suggest that the compound is persistent, with 300-600 days half-life. We conducted a 63-day laboratory incubation to evaluate tebuconazole's dissipation kinetics and impact on soil microbial activity in Tifton loamy sand. Tifton soils support extensive peanut production in the Atlantic Coastal Plain region of Georgia and Alabama. Products containing tebuconazole are applied to an estimated 50% of the peanut acreage in the region. At the end of the incubation, 43 (+/-42)% of the parent compound was recovered in soil extracts. The first-order kinetic model, which gave a good fit to the dissipation data (r2 = 0.857), yielded a soil half-life (t1/2) of 49 days. This is 6-12 times more rapid than t1/2 values described in unpublished tebuconazole registration documents. Four degradates were identified. Tentative structural assignments indicated that degradates were derived from hydroxylation of the parent compound and/or chlorophenyl ring cleavage. Cleavage products showed a steady increase during the incubation, and on a molar basis were equal to 63% of the time zero tebuconazole concentration. No significant effect on soil microbial biomass was observed, indicating that when the compound is applied at normal agronomic rate it does not impact soil metabolic activity. Use of the soil-half life data derived in this study should improve the accuracy oftebuconazole fate assessments for Coastal Plain peanut production. The study also indicated that environmental assessment of selected degradates may be needed to fully evaluate risks of tebuconazole use.
Repeated application may increase rates of pesticide dissipation in soil and reduce persistence. The potential for this to occur was investigated for the fungicide, tebuconazole (alpha-[2-(4-chlorophenyl)ethyl]-alpha-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol), when used for peanut (Arachis hypogaea L.) production. Soil samples were collected from peanut plots after each of four tebuconazole applications at 2-wk intervals. Soil moisture was adjusted to field capacity as necessary and samples were incubated in the laboratory for 63 d at 30 degrees C. Untreated plot samples spiked with the compound served as controls. Results indicated accelerated dissipation in field-treated samples with the time to fifty percent dissipation (DT50) decreasing from 43 to 5 d after three tebuconazole applications. Corresponding increases in rates of accumulation and decay of degradates were also indicated. Best-fit equations (r2 = 0.84-0.98) to dissipation kinetic data combined with estimates of canopy interception rates were used to predict tebuconazole and degradates concentration in soil after each successive application. Predicted concentrations compared with values measured in surface soil samples were from twofold less to twofold greater. Use of kinetic data will likely enhance assessments of treatment efficacy and human and ecological risks from normal agronomic use of tebuconazole on peanut. However, the study indicated that varying soil conditions (in particular, soil temperature and water content) may have an equal or greater impact on field dissipation rate than development of accelerated dissipation. Results emphasize that extension of laboratory-derived kinetic data to field settings should be done with caution.
The impacts of the fungicides azoxystrobin, tebuconazole and chlorothalonil on microbial properties were investigated in soils with identical mineralogical composition, but possessing contrasting microbial populations and organic matter contents arising from different management histories. Degradation of all pesticides was fastest in the high OM/biomass soil, with tebuconazole the most persistent compound, and chlorothalonil the most readily degraded. Pesticide sorption distribution coefficient (K(d)) did not differ significantly between the soils. Chlorothalonil had the highest K(d) (97.3) but K(d) for azoxystrobin and tebuconazole were similar (13.9 and 12.4, respectively). None of the fungicides affected microbial biomass in either soil. However, all fungicides significantly reduced dehydrogenase activity to varying extents in the low OM/biomass soil, but not in the high OM/biomass soil. The mineralization of subsequent applications of herbicides, which represents a narrow niche soil process was generally reduced in both soils by azoxystrobin and chlorothalonil. 16S rRNA-PCR denaturing gradient gel electrophoresis (DGGE) indicated that none of the fungicides affected bacterial community structure. 18S rRNA PCR-DGGE analysis revealed that a small number of eukaryote bands were absent in certain fungicide treatments, with each band being specific to a single fungicide-soil combination. Sequencing indicated these represented protozoa and fungi. Impacts on the specific eukaryote DGGE bands showed no relationship to the extent to which pesticides impacted dehydrogenase or catabolism of herbicides.
The effects of solid, dissolved organic matter and of pH on copper mobility in a copper-contaminated sandy soil has been studied in the laboratory as well as in the field. The soil, with pH ranging from 3.8 to 5.7, had been polluted with copper in the range from 0.13 to 1.9 mmol/kg more than 1 decade ago. Copper bound by dissolved organic matter (purified humic acid) was determined by a Cu ion selective electrode (Cu-ISE) in a pH range from 4 to 8 and a free copper range from 10-4 to 10-12 mol/L. Column experiments were carried out to investigate the mobility of DOC itself and the effect of DOC on Cu mobility. Copper binding by dissolved organic matter (DOC) as well as copper binding by (soil) solid organic matter (SOC) could be described well with the non-ideal competitive adsorption (NICA) model and with the Two Species Freundlich (TSF) model. Both models could be used to predict the copper concentration at different depths in a field using the total Cu content, pH, and solid and dissolved organic matter content. At pH 3.9 about 30% of the Cu in solution was copper bound by DOC, and at pH 6.6 CuDOC comprised more than 99%. DOC mobility was very sensitive to pH and calcium concentration.
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 raisedDHaseand urease activity tomaximumlevels (>3 mg INTF g�1 h�1 and
>47 mg NH4
+ g�1 h�1, respectively). The application of urea to the unamended and vermicompostamended
soil decreased diuron persistence from18.8 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.
This work studies the effects of wood amendments on soil microbial community functioning and on the potential of this community for linuron degradation. For this purpose, soil dehydrogenase activity and the number of live bacteria, which represent broad scale measurements of the activity and viability of soil organisms, were assessed in soil treated with linuron and either amended with pine or oak wood or unamended (sterilized and non-sterilized). The overall results show that the microbial community had a significant role in linuron degradation. The linuron half-life values indicated a slower degradation rate in pine and oak amended soils than in unamended ones. This is attributed both to the higher sorption of linuron by these soils compared to the unamended ones and a consequent lower bioavailability of the herbicide for microbial degradation, and to the use of the pine and oak as an alternative carbon source by degrading microorganisms. Linuron did not affect the microbial community in terms of dehydrogenase activity and number of live bacteria, presumably because it had adapted to the herbicide. However, the dehydrogenase activity was significantly higher in the soils amended with pine or oak than in the non-amended ones, indicating that the presence of a carbon source favoured the overall bacterial community.
The use of fungicides in agriculture, to protect plants from soil-borne pathogens, is a common practice. However, there is a dearth of information on the side-effects of fungicides on key soil ecological processes. We investigated the effects of three fungicides, benomyl, captan and chlorothalonil, on soil microbial activity (substrate-induced respiration and dehydrogenase activity), and nitrogen dynamics (NH4–N and NO3–N) in two laboratory experiments, one with captan and chlorothalonil and another with captan. In each laboratory batch incubation, soil was treated with a fungicide at approximately recommended field application rates (benomyl, 51 mg a.i. kg−1, captan,125 mg a.i. kg−1 and chlorothalonil, 37 mg a.i. kg−1) and incubated at 30°C for 8 weeks. Some soils were amended with either ground alfalfa leaves or ground wheat straw to provide additional substrates for soil microorganisms and to alter rates of nitrogen mineralization/immobilization. All three fungicides suppressed the peak soil respiration in unamended soil by 30–50%, but the three fungicides had different effects in the amended soils. Soil dehydrogenase activity was stimulated by benomyl (18–21%) and chlorothalonil (8–15%) except in the alfalfa amended soil, but was decreased by captan (40–58%) in both the straw-amended and unamended soils. The fungicide-treated soils in general had less microbial biomass N concentrations than the untreated soils. Captan-treated soils had much higher NH4 N concentrations than the control soils, with or without the organic amendments. Benomyl and chlorothalonil had little influence on soil NH4 N concentrations. Net N mineralization and nitrification rates were influenced by all fungicide treatments as well as by the addition of organic materials. N mineralization rates were significantly higher in captan-treated soils than in untreated soils. N dynamics were influenced by chlorothalonil in a similar pattern to captan but reached peak nitrification rates earlier (day 7), in the alfalfa-amended soil. The effects of the three fungicides on soil microbial activity and nitrogen dynamics depended on the quality of the organic materials added to the soil. The patterns of effects of the fungicides on soil nutrient cycling processes were not large and were specific to each fungicide. Captan appeared to have more pronounced overall effects on soil microbial activity and nitrogen dynamics than either benomyl or chlorothalonil.
The dissipation of three insecticides (pirimicarb, pyriproxyfen and buprofezin) and three fungicides (cyprodinil, fludioxonil and tebuconazole) in peppers was evaluated in a study carried out on an experimental greenhouse. Pepper samples were collected during 6 week period in which two successive applications of these pesticides were performed. Gas chromatography (GC) with nitrogen–phosphorus detection (NPD) was used to study the disappearance of these compounds in peppers. Confirmation analysis of pesticides was carried out by capillary gas chromatography coupled with mass spectrometry in the selected ion monitoring (SIM) mode. At the preharvest interval the residue levels were below the legal limit established in Spain. The disappearance rates of these compounds on peppers were described as pseudo-first-order kinetics (r between 0.953 and 0.997) and half-life in the range of 4.41 and 21.47 days. After thirty days under cold and darkness storage conditions, dissipation of buprofezin and pyriproxyfen were not observed. However, dissipation rate in pepper of pirimicarb cyprodinil, fludioxonil and tebuconazole in refrigerated were observed. This, the half-lives for these pesticides were 5–9 times greater under refrigeration.
The effects of bovine manure (BM) on the degradation of hexazinone and formation of three of its major metabolites were investigated in sandy loam soil. The degradation half-life of hexazinone was 29.6 days in unamended soil, while it decreased to 21.8 days in BM-amended soil. The major metabolites formed in unamended soil were [3-cyclohexyl-6-(methylamino)-1-methyl-1,3,5-triazine-2,4(1, 3H)-dione] (metabolite A) and [3-cyclohexyl-1-methyl-1,3,5-triazine-2,4,6(1, 3, 5H)-trione] (metabolite C), while metabolite B [3-(4-hydroxycyclohexyl)-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1, 3H)-dione] was not detected over the entire experimental period. However, in BM-amended soil, metabolite B was detected at 20 and 40 days after incubation, suggesting that BM contributed to formation of this metabolite. N-demethylation, removal of the dimethylamino group with formation of a carbonyl group at the 6-position of the triazine ring appeared to be the principal mechanisms involved in hexazinone metabolism in unamended soil. However, hydroxylation at the 4-positon of the cyclohexyl group as well as the above two modes were the principal pathways in BM-amended soil.
Pesticides are typically applied as mixtures and or sequentially to soil and plants during crop production. A common scenario is herbicide application at planting followed by sequential fungicide applications post-emergence. Fungicides depending on their spectrum of activity may alter and impact soil microbial communities. Thus there is a potential to impact soil processes responsible for herbicide degradation. This may change herbicide efficacy and environmental fate characteristics. Our study objective was to determine the effects of 4 peanut fungicides, chlorothalonil (2,4,5,6-tetrachloro-1,3-benzenedicarbonitrile), tebuconazole (α-[2-(4-chlorophenyl)ethyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol), flutriafol (α-(2-fluorophenyl)-α-(4-fluorophenyl)-1H-1,2,4-triazole-1-ethanol), and cyproconazole (α-(4-chlorophenyl)-α-(1-cyclopropylethyl)-1H-1,2,4-triazole-1-ethanol) on the dissipation kinetics of the herbicide, metolachlor (2-chloro-N-(6-ethyl-o-tolyl)-N-[(1RS)-2-methoxy-1-methylethyl]acetamide), and on the soil microbial community. This was done through laboratory incubation of field treated soil. Chlorothalonil significantly reduced metolachlor soil dissipation as compared to the non-treated control or soil treated with the other fungicides. Metolachlor DT50 was 99 days for chlorothalonil-treated soil and 56, 45, 53, and 46 days for control, tebuconazole, flutriafol, and cyproconazole-treated soils, respectively. Significant reductions in predominant metolachlor metabolites, metolachlor ethane sulfonic acid (MESA) and metolachlor oxanilic acid (MOA), produced by oxidation of glutathione-metolachlor conjugates were also observed in chlorothalonil-treated soil. This suggested that the fungicide impacted soil glutathione-S-transferase (GST) activity. Fungicide DT50 was 27–80 days but impacts on the soil microbial community as indicated by lipid biomarker analysis were minimal. Overall study results indicated that chlorothalonil has the potential to substantially increase soil persistence (2-fold) of metolachlor and alter fate and transport processes. GST mediated metabolism is common pesticide detoxification process in soil; thus there are implications for the fate of many active ingredients.
The aim of this work was to study the effect of soil application of a solid waste from olive oil production (alperujo) on diuron and terbuthylazine retention in the field. Laboratory sorption experiments of the herbicides in unamended soil and soil amended with alperujo (A) or composted alperujo (CA) were performed, and a field study was conducted for 2 consecutive years. Three subplots composed of four olive trees were randomly selected from a 50-ha olive grove (SE Spain) for three different treatments: soil without amendment (S plots), soil amended with uncomposted alperujo (S + A plots) and soil amended with composted alperujo (S + CA plots). Uncomposted alperujo was applied to S + A plots during 4 consecutive years at the rate of 18 Mg ha−1 and composted alperujo was applied to S + CA plots for the first time on April 2005 at the rate of 8 Mg ha−1. On April 2006, 15 Mg ha−1 of A was applied to S + A plots, and 13 Mg ha−1 of CA was applied to S + CA plots. Manual application of both A and CA was followed by soil tillage to a 5 cm depth. A commercial herbicide formulation (28.5% diuron and 28.5% terbuthylazine) was applied to S, S + A and S + CA subplots and soils were sampled periodically at 0–10, 10–20 and 20–30 cm depth and extracted for their herbicide content. Results from laboratory studies indicated higher herbicide sorption upon amendment with both A and CA when compared to unamended soil. Field studies revealed higher amounts of diuron and terbuthylazine in every plot and almost all sampling dates in the first 10 cm of soil. Soil amendment with alperujo gave rise to higher amounts of herbicide in the soil when compared to unamended soil, and this is specially significant in the case of the herbicide diuron and plots amended with uncomposted alperujo.
The aim of this research was to study the inhibitory effect of chlorpyrifos (CPF) on soil microbial activity and to evaluate the efficacy of different organic amendments as a biostimulation agent for sustaining the microbial activity and thereby assisting in the remediation of CPF (10 ppm) contaminated soil. Experiments were carried out under controlled conditions (37 °C) up to 74 days; CPF was analyzed by GC-ECD while dehydrogenase activity (DHA) was measured as one of the indices of soil microbial activity. Throughout the experiment, there was higher microbial activity in uncontaminated soil (S) as compared to CPF contaminated soil (SP) and overall a considerably high reduction (63.51%) in average DHA was noticed in CPF contaminated soil. Organic amendments enhanced the microbial activity over unamended CPF contaminated soil. The trend of DHA on 24th day was MS (SP + 1% Mushroom Spent) >VC (SP + 1% Vermicompost) >BS (SP + 1% Biogas Slurry) >SP (Soil spiked with 10 ppm CPF) >FM (SP + 1% Farmyard Manure). The enhancement in pesticide dissipation over the unamended soil showed the following trend VC (37%)>MS (24%) >FM (1.9%). In spite of sufficient DHA, BS could not enhance pesticide dissipation over the unamended soil (SP). These results indicate the potential of vermicompost and mushroom spent compost as suitable biostimulation agents to sustain the microbial activity in CPF contaminated soil.
Mobility of fungicides penconazole and metalaxyl in unamended and amended vineyard soils with fresh and composted spent mushroom substrates (F-SMS and C-SMS) was studied. Experiments were performed in non-incubated and incubated (outdoors for 77 days) undisturbed soil cores under non-saturated flow conditions. Breakthrough curves (BTC) of metalaxyl leaching were delayed with regard to the tracer ion, and they showed an incomplete leaching in all soil cores after the addition of 2.5-4.5 pore volumes. A decrease of the maximum peak concentration in C-SMS soils with regard to unamended soils (up to 24-fold in Viana soil) and an increase in the fungicide retention by soils (up to 8-fold in the first segment of Viana soil core) was observed. However, a decrease (up to 2.6-fold in Sajazarra soil) or an increase (up to 1.4-fold in Aldeanueva soil) of the maximum peak concentration in F-SMS soils was observed. No leaching of penconazole was observed in all cases. After fungicide incubation in soil cores, the amounts of metalaxyl retained and leached decreased significantly by 1.24-37.8-fold and 1.17-302-fold, respectively, whereas no changes were observed for penconazole. Degradation of metalaxyl occurred in non-incubated soil and increased after incubation (two metalaxyl metabolites were detected in the leachates and the soil extracts), but it was not seen for penconazole in any case. In consequence, the addition of SMS as amendment to soil (especially C-SMS) enhanced adsorption of both fungicides, although metalaxyl could be available for degradation. This effect contributes to prevent groundwater contamination by metalaxyl, but it could contribute to increase the surface water contamination by penconazole, because adsorption protects this fungicide from degradation, increasing its persistence in soils.
A simple and reliable analytical method for chlormequat residues in cotton and soil was established in this study. The residual levels and dissipation rates of chlormequat in cotton crops and soil were determined by High Performance Liquid Chromatography-Mass Spectroscopy (HPLC-MS). The limit of quantification (LOQ) was 0.05, 0.1, 0.1mg/kg for soil, cotton seeds and cotton leaves, respectively. The mean half-life of chlormequat was 4.47 days in cotton plants and was 4.34 days in soil. The final residues of chlormequat in cotton seeds were below 0.5mg/kg (the MRL of China), while the chlormequat residues could not be detected in soil. Low residues in cotton seed and soil suggest that this pesticide may be safe to use under the recommended dosage.
The contamination of agricultural soils with inorganic (Cu-based) and organic pesticides (including their residues) presents a major environmental and toxicological concern. This review summarizes available studies published on the contamination of vineyard soils throughout the world with Cu-based and synthetic organic fungicides. It focuses on the behavior of these contaminants in vineyard soils and the associated environmental and toxicological risks. The concentrations of Cu in soils exceed the legislative limits valid in the EU in the vast majority of the studied vineyards. Regarding the environmental and toxicological hazards associated with the extensive use of fungicides, the choice of fungicides should be performed carefully according to the physico-chemical properties of the soils and climatic and hydrogeological characteristics of the vine-growing regions.
The effect of the addition of fresh and composted spent mushroom substrates (F-SMS and C-SMS) to vineyard soils on the adsorption-desorption of penconazole and metalaxyl was studied under laboratory conditions. SMS is a promising agricultural residue as an amendment to increase the soil organic matter (OM) content. It may also modify the behavior of fungicides applied to vineyards. Freundlich Kf adsorption constants of both fungicides by soils and subsoils from three experimental plots unamended and amended in the field ranged between 2.78 and 13.4 (penconazole) and 0.14 and 0.67 (metalaxyl) with scant differences for unamended soil and subsoil. However, Kf values of amended soils were higher than those corresponding to subsoils and generally higher than those of unamended soils (up to 2.3 times for penconazole and 1.3 times for metalaxyl). The influence of SMS treatment (fresh or composted) was observed in the adsorption of the most hydrophobic fungicide penconazole. Simple and multiple correlations between soil and subsoil properties and adsorption constants indicated the influence of the OM on the adsorption of both fungicides, together with the clay, silt, and CaCO(3) content for metalaxyl and the pH for penconazole. The results revealed changes in the adsorption-desorption processes of these fungicides, which could give rise to a decrease in the mobility of metalaxyl (highly water-soluble) and an increase in the retention of penconazole (more hydrophobic). These effects could have an impact on surface and/or groundwater contamination.
Terbuthylazine (TA) is a herbicide that has been introduced for weed control in corn cultivations as a direct replacement for atrazine. Because incorporation of different organic amendments (OAs) is a common practice in this crop, this study investigated the effects of different OAs, including urban sewage sludge, poultry compost, and corn straw on the dissipation and metabolism of TA. A column study and a field dissipation study were used. In the column study, no residues of TA and desethyl-terbuthylazine (DETA) were detected in the leachate of amended and non-amended columns. The addition of OAs increased the persistence of TA and DETA in the upper soil layers (0-10 cm) but did not affect the mobility of TA and DETA in either experiment. Although the presence of OAs led to a significant increase in DETA production in the upper soil layers, the presence of DETA in lower depths did not significantly differ with the non-amended soil in either experiment. A gradual accumulation of DETA was evident in the soil layers amended with corn straw, whereas a rapid formation of DETA and a gradual decline thereafter was observed in the other treatments. Overall, the addition of OAs did not appear to significantly influence the mobility of TA and DETA, which did not move below the top 30 cm, thus indicating low risk for ground water contamination. In addition, the dissipation rate of TA in the field was faster than that in the column study.