稻田反硝化速率测定方法研究进展

反硝化作用是淹水稻田肥料氮损失的主要途径之一.采用合适的反硝化测定方法是开展稻田反硝化作用研究的前提.然而,由于反硝化过程主要产物N2的大气背景值较高,以及反硝化作用具有高度时空异质性,淹水稻田反硝化作用损失氮量难以准确量化一直是阻碍科学评价稻田气态氮损失的关键难题.本文综述了研究稻田反硝化作用的4种方法(乙炔抑制法、...

Methods for Measuring Denitrification in Flooded Rice Paddies: A Review

Denitrification is a microbially facilitated process where nitrate (NO₃^-) is reduced and ultimately produces dinitrogen(N₂) through a series of intermediate nitrogen oxide products, i.e., nitrite, nitric oxide, nitrous oxide. Denitrification has long been considered as one of the major pathways of nitrogen (N) loss when N fertilizer is applied to flooded rice paddies. However, due to the high atmospheric background concentrations of N₂, the main denitrification product, and the high spatio-temporal heterogeneity of denitrification, it is difficult to accurately quantify denitrification rates in flooded rice paddies, which hinders the scientific evaluation of N loss from paddies. The selection of appropriate methods for determination of denitrification is the basis for studying denitrification in paddies. In this paper, four approaches developed to measure denitrification in flooded rice paddies were reviewed, i.e., acetylene inhibition technique, ¹⁵N tracing method, helium environment-direct N₂ quantification, and N₂/Ar ratio-membrane inlet mass spectrometry, and the advantages, disadvantages and feasibility of these methods were discussed, and some suggestions were proposed in order to promote the future research of denitrification in paddies.