02601naa a2200301 a 450000100080000000500110000800800410001902400410006010000190010124501260012026000090024652017340025565000130198965000150200265000210201765000130203865000190205165000200207065000140209065000090210465300280211365300220214165300210216365300230218470000220220770000180222977300520224721791662025-12-01       2025    bl uuuu     u00u1 u    #d7 ahttps://doi.org/10.1071/SR242252DOI1 aNOVOTNY, E. H.  aLong-term experiments on atrazine adsorption in biochar-amended soils in Brazilian tropical areas.h[electronic resource]  c2025  aBiochar has been recommended to improve soil fertility. Biochar may alter the sorptive properties of soil due to its high sorption capacity for organic molecules. However, there is relatively little information in the literature on the medium- and long-term impacts of biochar on soil sorptive capacity based on in situ field experiments. The aim of this study was to evaluate the long-term effect of biochar on atrazine adsorption in field trials. Adsorption isotherms were measured in two field experiments, up to 6 years following a single 16 Mg ha−1 biochar application. Compared to the control, the Freundlich solid–water distribution coefficient was higher in the biochar-amended soils. This effect decreased with time, but remained significantly higher compared with the control treatment up to 5 years after the single biochar application. Biochar increased the soil sorption capacity, with a residual effect observable 5 years after a single biochar application. The decrease in sorption capacity of biochar-treated soils over time is likely attributable to the obstruction and/or saturation of biochar sorption sites by clay and indigenous soil organic matter, in addition to pore occlusion. The enhancement of soil sorption capacity with biochar is important for reducing atrazine pollution, a pesticide with high soil mobility and environmental persistence. The biochar’s residual effect indicates its efficacy in regulating the mobility of atrazine. However, the negative effects of increased soil sorption capacity due to biochar must also be considered. Pesticide efficacy may decrease, necessitating higher dosages, while the environmental persistence of organic contaminants could potentially increase.  aCharcoal  aPesticides  aResidual effects  aSorption  aContaminação  aEfeito Residual  aPesticida  aSolo  aFreundlich coefficients  aLong-term kinetic  aPyrogenic carbon  aSoil contamination1 aRESENDE, M. F. de1 aMADARI, B. E.  tSoil Researchgv. 63, n. 5, SR24225, Aug. 2025.