Exploring the Fate of Substituted 1,2,3-Triazoles: Unraveling the Soil Degradation Pathways of a Novel Class of Nitrification Inhibitors
Sidhu, P. K., & Wille, U., Exploring the Fate of Substituted 1,2,3-Triazoles: Unraveling the Soil Degradation Pathways of a Novel Class of Nitrification Inhibitors, ACS Agricultural Science & Technology. DOI: https://doi.org/10.1021/acsagscitech.5c00452
Nitrification inhibitors are used in agriculture to maintain ammonium (NH4+) available for crops for longer periods while reducing leaching of nitrate (NO3–) and emission of the potent greenhouse gas nitrous oxide (N2O). Unfortunately, the current commercial inhibitors exhibit inconsistent performances across various agroecosystems, underscoring the need for the development of new inhibitors to increase agriculture’s environmental sustainability. We recently presented 1,4-disubstituted 1,2,3-triazoles as a novel class of nitrification inhibitors (NIs), which can outperform the commercial ‘gold standard’ 3,4-dimethylpyrazole phosphate (DMPP) in laboratory soil incubations. In this work, we explored the stability of two 1,4-disubstituted 1,2,3-triazoles in relation to their effectiveness as nitrification inhibitors in an agricultural soil. By measuring the concentration–time profiles for these NIs in the presence of N fertilizer as well as for NH4+-N loss and NO3–-N formation, it was found that a threshold concentration in the soil is required for nitrification inhibition. Both NIs undergo degradation through the oxidation of the substituents and successive shortening of the hydrocarbon chains, leaving the triazole ring intact. These reactions occur in both nonsterilized and sterilized soil, suggesting that abiotic processes are responsible for the degradation, which likely proceeds via radical intermediates.
