Biochar changes the bioavailability and bioefficacy of the allelochemical coumarin in agricultural soils.

摘要: BACKGROUND Allelochemicals can act as biopesticides or enhance the action of synthetic pesticides. In this work, we assessed bioavailability allelochemical coumarin in soils amended with fresh field-aged biochars (BCs). The BC from oak wood (Fresh BC) was prepared at 550 °C and buried for aging two different places: a sandy loam soil Spain 15 months (Aged BC_1) USA six months BC_2). RESULTS Sorption experiments showed that all BCs were able to increase affinity towards coumarin, distribution coefficient following order: unamended < Aged BC_2-amended BC_1-amended Fresh BC-amended soil. All ensure greater persistence effect more pronounced high chemical dose (10 mg kg-1 ). Conversely, leaching studies columns revealed maintain within first 5 cm top-soil total amount extracted ranging between 17% 22% <1% Leaching only observed when added highest rate. Likewise, bioefficacy against lettuce enhanced 10 kg ha-1 CONCLUSIONS Biochar application agricultural is promising tool management natural compounds potential use biopesticides, such because it increases sorption, and, some cases, bioefficacy. results reveal still persists soils.