Ecotoxicological assessment of Fluazuron: effects on Folsomia candida and Eisenia andrei.

The cattle production in Brazil has increased considerably in the last years, mainly due to the control of parasite infestation of the animals, which cause loss of productivity to the sector. Fluazuron is an active ingredient (a.i.) of the benzoylurea class used to control ticks in cattle. As this a.i. has been found unchanged in animal feces, which may present a risk to edaphic organisms, this study aimed to assess the effects of fluazuron on survival, reproduction, and behavior of the soil invertebrates Folsomia candida and Eisenia andrei, through ecotoxicological assays. We carried out bioassays in a tropical artificial soil (TAS) spiked with increasing doses of the insecticide. Earthworm mortality was found only at the highest tested fluazuron concentration (LOEC = 160 mg a.i. kg-1 dry soil and NOEC = 80 mg kg-1), while the reproduction of F. candida and E. andrei was reduced at lower fluazuron concentrations (EC50 = 4.48 mg kg-1 and EC50 = 20.8 mg kg-1, respectively). Avoidance behavior was detected for both species at lower concentrations than those that caused impacts on reproduction, indicating that the substance may affect the soil habitat function. Since the possible adverse effects of fluazuron on edaphic fauna are still unknown or neglected, this study also warns about the possible harmful effect of veterinary pharmaceutical products on edaphic fauna.

Economic and soil quality indicators in soybean crops grown under integrated crop-livestock and winter-grain cultivation systems / Relação entre indicadores econômicos e edáficos de qualidade do solo em lavouras de soja com ILP ou produção de grãos no inverno

ABSTRACT: This study aimed to evaluate the relationship between economic indicators of soybean crops ( Glycine max L.) cultivated with Crop-Livestock Integration (CLI) or with grain production in winter, and the chemical, physical and biological attributes of the soil. It was selected ten agricultural sites in Santa Catarina to measure economic results and edaphic attributes, data was submitted to a Principal Components Analysis (PCA). Results indicated that soybean production in the summer and grain production in the winter yielded better economic results compared with summer soybean and CLI in winter. This reflects the higher productivity of the crops (9.1%) and the improved chemical, physical, and biological attributes of the soil (with the exception of organic matter content and macroporosity, which were better under the soybean system with CLI).

RESUMO: O estudo teve como objetivo avaliar a relação entre resultados econômicos de lavouras de soja ( Glycine maxL.) cultivadas com Integração Lavoura-Pecuária (ILP) ou produção de grãos no inverno e atributos químicos, físicos e biológicos do solo. Foram selecionadas dez propriedades rurais, consideradas referência em Santa Catarina, para a determinação dos resultados econômicos das lavouras de soja e dos atributos edáficos, que foram submetidos à análise de componentes principais (ACP). Os resultados indicam que o sistema de produção de soja no verão e grãos no inverno apresentou melhores resultados econômicos em comparação com o sistema de soja no verão e ILP no inverno. Este resultado decorre da maior produtividade das lavouras (9,1%), devido às melhores condições químicas, físicas e biológicas do solo, com exceção do teor de matéria orgânica e da macroporosidade, que ficaram mais associadas ao sistema soja com ILP.