Nitrous oxide emissions from terrestrial ecosystems in China

Abstract

N₂O emissions from agricultural, forest and grassland ecosystems in China were in situ measured by closed chamber method, and estimation of total annual N₂O emissions from these ecosystems and a technique mitigating N₂O emission from agricultural soil were reported. The results showed: (1) the annual emissions of N₂O from rice, maize, soybean and wheat field, temperate forest and temperate grassland in China were 1.08–2.99, 0.47–4.51, 1.98, 1.02–2.93, 0.28–1.28 and 0.27–0.61 kg $\text{N}{}_2\text{O}\text{–}\text{N}\text{ha}{}^{\mathrm{-1}}$, respectively. The total annual N₂O emissions from agricultural, forest and temperate grassland ecosystems in China were estimated as 152.49, 94.10 and 112.13 Gg N, respectively. Industrially co-crystallized ammonium bicarbonate (AB) with dicyandiamide, substituting for ammonium bicarbonate in China, decreased N₂O emission significantly from a meadow brown soil in laboratory (80.2% at soil moisture 12% and 40.0% at soil moisture 22%, respectively) and upland field condition (74.0%).