Leaching and degradation of corn and soybean pesticides in an Oxisol of the Brazilian Cerrados

Laabs, Volker; Amelung, Wulf; Pinto, Adílson Luiz; Altstaedt, A.; Zech, Wolfgang

doi:10.1016/s0045-6535(99)00546-9

Cited by 119 publications

(95 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Corrêa et al (2003) observaram, em condições de campo em Piracicaba, SP, que o endossulfam não lixiviou abaixo de 20 cm de profundidade e atribuíram este fato às características lipofílicas do endossulfam (K OC > 5700 mL g -1 ), o que proporciona sua alta afinidade pelas partículas do solo. Da mesma forma, Laabs et al (2000) observaram que o α-endossulfam ficou imóvel no solo após aplicação em uma área agrícola de Mato Grosso.…”

Section: Methodsunclassified

“…Nos primeiros 41 dias após a aplicação o endossulfam se concentrava na camada superficial do solo e a temperatura média máxima do ar observada neste período foi de 32 °C com precipitação total igual a 233 mm. Estudos têm mostrado evidências de volatilização intensa de agrotóxicos em condições tropicais brasileiras (Laabs et al, 2000;Nogueira et al, 2012;Scorza Júnior & Regitano, 2012). Laabs et al (2000) observaram TD 50 para α-endossulfam igual a 2,5 dias após sua aplicação em condições de campo em Mato Grosso.…”

Section: Methodsunclassified

“…Estudos têm mostrado evidências de volatilização intensa de agrotóxicos em condições tropicais brasileiras (Laabs et al, 2000;Nogueira et al, 2012;Scorza Júnior & Regitano, 2012). Laabs et al (2000) observaram TD 50 para α-endossulfam igual a 2,5 dias após sua aplicação em condições de campo em Mato Grosso. Este pequeno valor de TD 50 indica uma rápida dissipação do α-endossulfam logo R. Bras.…”

Section: Methodsunclassified

See 2 more Smart Citations

Persistência de endossulfam e seu metabólito sulfato de endossulfam em condições de campo e laboratório

Júnior

Franco

Moraes

2013

Rev. bras. eng. agríc. ambient.

View full text Add to dashboard Cite

RESUMOObjetivou-se, neste trabalho, avaliar a persistência e a lixiviação de endossulfam no campo e sua degradação e formação do metabólito sulfato de endossulfam em condições de laboratório. Visando ao experimento da persistência e à lixiviação no campo, amostras de solo até a profundidade de 100 cm foram coletadas aos 0, 41, 74 e 125 dias após aplicação. Em laboratório amostras de solo nas profundidades de 0-30 e 50-70 cm foram incubadas a 30 ± 2 °C e 80% da capacidade de campo e os resíduos de endossulfam e sulfato de endossulfam foram quantificados em função do tempo para ajuste dos modelos de cinética de primeira ordem e do modelo bifásico. Observou-se, no campo, que o endossulfam não lixiviou para menos de 10 cm de profundidade e houve uma rápida dissipação resultando em uma quantidade remanescente no perfil do solo (100 cm) inferior a 1% da dose aplicada aos 41 dias após a aplicação. Em laboratório os valores de TD 50 para o endossulfam variaram de 17 a 26 dias e para o sulfato de endossulfam de 26 a 59 dias. O modelo de degradação bifásico mostrou-se superior ao de cinética de primeira ordem para descrever a degradação do endossulfam em laboratório. Palavras-chave: degradação, meia-vida, lixiviação, dissipaçãoPersistence of endosulfan and its metabolite endosulfan sulfate under field and laboratory conditions ABSTRACT This study aimed to evaluate endosulfan leaching and persistence in the field as well as its degradation and formation of the metabolite endosulfan sulfate under laboratory conditions. For the persistence experiment and leaching in the field, soil samples until 100 cm depth were collected at 0, 41, 74, and 125 days after application. In the laboratory, soil samples of 0-30 cm and 50-70 cm depth were incubated at 30 ± 2 ºC and 80% field capacity and endosulfan residues were quantified as a function of time for adjusting the first order kinetics and biphasic models. In the field, it was observed that endosulfan did not leach beyond 10 cm depth and there was a rapid dissipation resulting in a quantity in the soil profile (100 cm) less than 1% of the applied dose at 41 days after application. In laboratory TD 50 values for endosulfan ranged from 17 to 26 days and endosulfan sulfate 26-59 days. The biphasic decay model was superior to the first-order kinetics to describe the degradation of endosulfan in the laboratory.

show abstract

Section: Methodsunclassified

See 1 more Smart Citation

Persistência de endossulfam e seu metabólito sulfato de endossulfam em condições de campo e laboratório

Júnior

Franco

Moraes

2013

Rev. bras. eng. agríc. ambient.

View full text Add to dashboard Cite

show abstract

“…A 10 μg mL -1 atrazine working solution in 40 mmol L -1 BR buffer at pH 2.0 was studied in presence of 0.050, 0.10, 0.25, and 0.50 mol L -1 NaNO 3 . These experiments were performed using a frequency of 60 Hz, flow rate of 2.70 mL min -1 and Hg drop radius of 0.46 mm.…”

Section: Concentration Of Supporting Electrolyte and Hg Drop Radiusmentioning

confidence: 99%

“…Nowadays, atrazine and simazine are the most used triazines around the world. [2][3][4] Significant amounts of atrazine may be stored in soil after application. The amount and persistence of the herbicide bound to soil particles is dependent on many factors.…”

Section: Introductionmentioning

confidence: 99%

Developing a continuous flow-square wave voltammetry method for determination of atrazine in soil solutions using the hanging mercury drop electrode

Santos

Abate

Masini

2006

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

Este trabalho descreve o desenvolvimento de uma metodologia para a determinação de atrazina em solução de solo, utilizando Voltametria de Onda Quadrada em condições de Fluxo Contínuo, empregando o eletrodo de gota pendente de mercúrio. Para uma freqüência de 350 Hz e vazão de 0,47 mL min -1 , obteve-se a maior relação sinal/ruído, sendo que a curva analítica obtida em solução de solo na presença de tampão BR 40 mmol L -1 e NaNO 3 0,25 mol L -1 apresentou faixa linear entre 0,10 e 2,0 μg mL -1 , com limites de detecção e quantificação de 0,030 e 0,10 μg mL -1 , respectivamente. A metodologia proposta proporcionou significativo aumento da velocidade analítica em comparação à metodologia em batelada, além de proporcionar baixo consumo de amostra, sendo possível determinar 72 amostras por hora consumindo apenas 341 μL por análise. Os resultados foram similares aos obtidos por HPLC, mas o método proposto tem menor tempo de análise e não emprega solventes orgânicos.This work describes the development of a Continuous Flow-Square Wave Voltammetry method for determination of atrazine using the hanging mercury drop electrode. The best signal to noise ratio was obtained at the square wave frequency of 350 Hz and flow rate of 0.47 mL min -1 . Under these conditions, the analytical curve obtained in 0.010 mol L -1 CaCl 2 soil extracts in presence of 40 mmol L -1 BR buffer and 0.25 mol L -1 NaNO 3 was linear for atrazine concentrations between 0.10 and 2.0 μg mL -1 , with detection and quantification limits of 0.030 and 0.10 μg mL -1 , respectively. The proposed method increased the analytical throughput in comparison with the batch methodology, allowing a sampling frequency of 72 h -1 to be accomplished. Besides, the sample consumption is significantly reduced, and only 341 μL are necessary for each analysis. The results obtained were similar to the ones obtained by HPLC, but the proposed method is faster and does not use organic solvents. Keywords: continuous flow, atrazine, soil solution, square wave voltametry IntroductionThe use of pesticides has increased in the world because of the increasing food production. Brazil occupies the 5 th position in the ranking of the countries with the largest consumption of these chemicals. Despite of this fact, monitoring of pesticide residues in soils and waters is not frequent in the country. 1 Triazines have been used in several crops as pre and post emergence herbicides. Nowadays, atrazine and simazine are the most used triazines around the world. [2][3][4] Significant amounts of atrazine may be stored in soil after application. The amount and persistence of the herbicide bound to soil particles is dependent on many factors. These include the type of soil, percent of organic matter, amount of clay, soil pH, and soil structure. 5 Walker 6 showed that atrazine adsorption is directly related to the concentration organic matter and humidity of soils.A significant amount of atrazine may also be lost to surface runoff and into the groundwater via leaching from agricultural land. 5 In US...

show abstract

Stream‐valley systems of the Brazilian Cerrado: impact assessment and conservation scheme

Wantzen

Siqueira

Cunha

et al. 2006

Aquatic Conservation

View full text Add to dashboard Cite

1. The Cerrado, a seasonal savanna vegetation, is one of the largest biomes in the Neotropics. Conversion of Cerrado into agroecosystems has caused severe alterations in the species composition, functioning and habitat structure of streams and rivers. 2. As a case study for the Cerrado, the environmental quality of stream-valley systems was investigated in the catchment of the Tenente Amaral River near the city of Jaciara, Mato Grosso, Brazil. 3. Interpreting a Landsat-7 image of the area, and using a rapid assessment protocol with airborne and field observations, 481 first-order streams were identified in the catchment area (875.36 km2), equivalent to an average of 0.55 springs per square kilometre. The total stream density was 0.83 km km-2. 4. Only the uppermost headwater zones of the streams were unimpaired (8.5% of the stream channels). The largest part of the studied stream sectors were moderately (59.3%) or strongly (32.2%) impaired. 5. The greatest impact was caused by erosion. Sediments released by gully erosion alone were calculated as 2.6 × 106 m3 of sediments in the upper zone of one tributary of the Tenente Amaral River. The sediments had deleterious effects on fauna and flora. 6. The highly erosion-prone stream valleys in the Cerrado require full protection. In the transition area between agroecosystems and hillslopes, buffer zones consisting of a replanted interfluvial Cerrado tree vegetation and a vegetated buffer strip should be planted. Apart from erosion protection, these strips can provide valuable income for the farmers through selling non-wood products. 7. The legal situation providing the baseline for the protection of the Cerrado streams is reviewed, including the efforts of the Brazilian states and collaboration of UNESCO. 8. We suggest that it is possible to transfer this management strategy to similar biomes in the seasonal tropics provided that the tree species lists are carefully adapted to the regional flora

show abstract

Leaching and degradation of corn and soybean pesticides in an Oxisol of the Brazilian Cerrados

Cited by 119 publications

References 28 publications

Persistência de endossulfam e seu metabólito sulfato de endossulfam em condições de campo e laboratório

Persistência de endossulfam e seu metabólito sulfato de endossulfam em condições de campo e laboratório

Developing a continuous flow-square wave voltammetry method for determination of atrazine in soil solutions using the hanging mercury drop electrode

Stream‐valley systems of the Brazilian Cerrado: impact assessment and conservation scheme

Contact Info

Product

Resources

About