Nitrification inhibitors and their relationship with N2O emission in sugarcane (Saccharum spp.) cultivation in Colombia

Abstract

Nitrous oxide (N₂O) is a greenhouse gas (GHG) with a global warming potential 277 times stronger than CO₂, is emitted as a by-product of microbial activity during the anaerobic phase of the nitrogen cycle. The objective of this work was to analyze the influence of the use of nitrification inhibitors during nitrogen fertilization and its relationship with N₂O emission under specific conditions for sugarcane cultivation typical of the Cauca River valley. A randomized complete block experimental design was used with a 2X3 factorial arrangement with 4 replications, the first factor corresponds to the fractionation of the dose (single or fractionated dose), the second corresponds to the use of inhibitors (without inhibitor; N-[n-butyl] thiophosphoric triamide or mixture of NBPT with dicyandiamide), a total of 7 treatments were evaluated. For monitoring N₂O emissions, manual stationary cameras were used for field sampling and the gas chromatography technique was used to determine the N₂O concentration of these samples. Differences between treatments were observed, the N₂O emissions generated during the application of a fractional dose without inhibitors; single dose + NBPT and single dose without inhibitors were significantly higher compared to the other treatments. This research improves our ability to understand the benefits of using nitrification inhibitors during fertilizer applications on sugarcane crops in this region. N₂O emissions in most of the treatments with nitrification inhibitor application were lower. Further research is needed on the mechanisms of action of the inhibitors to increase their efficiency and other possible effects on the agroecosystem.