Soil Factors Effects on the Mineralization, Extractable Residue, and Bound Residue Formation of Aminocyclopyrachlor in Three Tropical Soils

Abstract

Abstract:Aminocyclopyrachlor is an herbicide that belongs to the new class of chemicals known as the pyrimidine carboxylic acids, which are used to control broadleaf weeds and brush. However, the environmental behavior and fate of aminocyclopyrachlor are not fully understood. The aim of the present study was thus to evaluate the mineralization, extractable residue and bound residue formation of aminocyclopyrachlor in three tropical soils with different physico-chemical properties. 14 C-labeled [pyrimidine-2-14 C] aminocyclopyrachlor was used to assess the fate of this herbicide in soil placed in biometer culture flasks. Total mineralization (accumulated 14 CO 2 ) of aminocyclopyrachlor was found to be <10% in all soils, decreasing in the following order: Oxisol-Typic Hapludox (clay) > Oxisol-Typic Hapludox (loamy sand) > Plinthosol-Petric (sandy clay). Overall, constant rate of mineralization (k) values for all soils were very low (0.00050% to 0.00079% 14 CO 2 day −1 ), with mineralization half-life times (MT50) consequently very high (877 to 1376 days), suggesting potential long persistence in soil. The amount of extractable residues decreased from~31% to 50% in all soils after 126 days of incubation, indicating an increase in bound residue formation from~5.0-to 7.5-fold compared to evaluation immediately after herbicide application, suggesting that degradation herbicide is involved in the formation of bound residues. Extractable residues are important factors that control mineralization and bound residue formation from aminocyclopyrachlor in the soil. The present study is the first to assess the fate, distribution, and formation of bound residues of aminocyclopyrachlor in soils. Aminocyclopyrachlor residues were predominantly associated with the OM and clay contents of soil. This effect of soil physico-chemical properties should be considered in environmental risk assessment of aminocyclopyrachlor and its application in the field for weed control.

Aplicación conjunta del consorcio microorganismos benéficos y FitoMas-E® incrementan los indicadores agronómicos del frijol

“…Los frijoles son las leguminosas de grano más importantes para el consumo humano, porque son una fuente de proteína y ricos en minerales, especialmente, hierro, zinc y vitaminas (Campa et al 2018;Calero Hurtado et al 2020c). La agricultura, se enfrenta a graves problemas de degradación de la tierra (Singh et al 2020); sistemas de cultivo intensivo, así como el desequilibrio en el uso de fertilizantes, son los factores principales que provocan desbalance de nutrientes, disminuyen la fertilidad del suelo, bajan la productividad y reducen la calidad de los alimentos (Francisco et al 2018).…”

Disipación de herbicidas en un suelo enmendado con residuos orgánicos: ensayos en campo e impacto en las comunidades microbianas del suelo

“…En la literatura actual puede encontrarse un gran número de estudios de degradación de diferentes herbicidas en suelos con diferentes propiedades en condiciones controladas. Francisco et al (2018) estudiaron el comportamiento del herbicida aminociclopiracloro en tres suelos con propiedades fisicoquímicas diferentes. Evaluaron la mineralización, los residuos extractables y la formación de residuos enlazados utilizando el herbicida marcado con 14 C en condiciones de laboratorio.…”