Effects on Water Quality of Pesticide use in Farmland Under Intensive Soil Management in Southern Brazil
Lúcio Fábio Lourençato
Department of Soil Science and Agricultural Engineering, Federal University of Paraná, Rua dos Funcionários, 1540, 80035-050, Curitiba, Brazil
Nerilde Favaretto *
Department of Soil Science and Agricultural Engineering, Federal University of Paraná, Rua dos Funcionários, 1540, 80035-050, Curitiba, Brazil
Fabrício Augusto Hansel
Embrapa-Forestry, Estrada da Ribeira km 111, Caixa Postal 319, CEP 83411-000, Colombo,Paraná, Brazil
Agnes de Paula Scheer
Department of Chemical Engineering, Federal University of Paraná, Prédio das Usinas Piloto, Bloco B, Caixa Postal 19083, Jardim das Américas, CEP 81531-990,Curitiba, PR, Brazil
Luiz Fernando de Lima Luz Junior
Department of Chemical Engineering, Federal University of Paraná, Prédio das Usinas Piloto, Bloco B, Caixa Postal 19083, Jardim das Américas, CEP 81531-990,Curitiba, PR, Brazil
Luiz Cláudio de Paula Souza
Department of Soil Science and Agricultural Engineering, Federal University of Paraná, Rua dos Funcionários, 1540, 80035-050, Curitiba, Brazil.
Jeferson Dieckow
Department of Soil Science and Agricultural Engineering, Federal University of Paraná, Rua dos Funcionários, 1540, 80035-050, Curitiba, Brazil
Andressa Cristhy Buch
Department of Soil Science and Agricultural Engineering, Federal University of Paraná, Rua dos Funcionários, 1540, 80035-050, Curitiba, Brazil
*Author to whom correspondence should be addressed.
Abstract
Poor soil management and intensive use of pesticides causes serious damage to soil and water quality in Brazil. To confirm this, two studies were conducted in an area with intensive farming in Southern Brazil with objectives to evaluate the level of pesticides in the river adjacent to the farmland during different seasons (river study) and to know the potential contamination resulting from surface runoff (runoff study). The river study was performed with samples from river water and riverbed sediment obtained over one year period with three months sampling period intervals (different seasons) on dry days (base flow effect). The runoff study was performed in the laboratory with simulated rainfall after recent pesticide application. The pesticides analyzed were Tebuconazole, Metalaxyl, Deltamethrin, Chlorothalonil, Glyphosate and its Metabolite-aminomethylphosphonic acid. They represented the most commonly used pesticides in the studied region. None of the pesticides tested were found in the river water or riverbed sediment samples at any sampling period. The detection limit in river water samples for Glyphosate and its metabolite was 5μg L-1 while it was 1 μg L-1 for the other pesticides. The runoff study (one hour rainfall) demonstrated that all the pesticides were present at high levels. It was 36μg L-1 for Tebuconazole, 3.24 μg L-1 for Metalaxyl, and 5.74 μg L-1 for Chlorothalonil in runoff samples, suggesting a high probability of contamination in downstream environments during intense rainfall events after recent pesticides application. The results highlight the importance of good management practices to prevent pesticides contamination of downstream environments due to runoff from agricultural lands.
Keywords: Agrochemical, catchment, land use, riverbed sediment, runoff, water quality