Mitigation of nitrous oxide emissions using a nitrification inhibitor, alternative pasture and forage plants and gibberellic acid

Abstract

In grazed pastures, nitrous oxide (N₂O), the potent greenhouse gas, is mostly emitted from animal excreta, particularly animal urine-N retuned to the soil during grazing. N₂O is produced in the soil through nitrification or denitrification. The first step of the nitrification process, ammonia oxidation, is a critical step of the N cycle which can significantly affect N₂O emissions. It is performed by ammonia oxidising bacteria (AOB) and archaea (AOA) in the soil. N₂O emissions are affected by a number of soil and environmental factors and major research efforts have been devoted to understanding these factors and developing effective mitigation technologies. This paper reports a series of laboratory and field studies designed to assess the effectiveness of different mitigation technologies for N₂O emissions in grazed pasture and forage systems, including the use of nitrification inhibitors, alternative pasture and forage plants, and the natural plant growth hormone, gibberellic acid (GA).