Abstract:
Tea garden soil is an important N
2O emission source. Understanding the N
2O emission factors of tea garden soil can provide a theoretical basis for reducing N
2O emission. Based on a global meta-analysis of tea garden soil from field
in-situ monitoring and microcosm incubation test, we quantify the annual N
2O emission of tea garden soil, and analyze the main influencing factors. Results suggested that the annual N
2O emissions from field
in situ monitoring of soil in global tea gardens averaged 16.82 kg hm
−2 (95% confidence interval is 12.99 - 21.27 kg hm
−2), while the microcosm incubation showed 0.04 mg kg
−1 d
−1(95% confidence interval is 0.02 - 0.07 mg kg
−1 d
−1). The average EF
d of tea garden soil was 2.25%, higher than the default value of Intergovernmental Panel on Climate Change (1%). The variance partition analysis (VPA) found that the amount of nitrogen application explained the maximum percentage (49.71%) of N
2O emission. The N
2O emissions from tea garden soil could be reduced 35%, 52% and 55% by application of controlled-release fertilizer, biochar and lime material, respectively. We conclude that a huge amount of N
2O emission from tea garden soil is induced by intensive fertilization, so the N
2O emission can be effectively reduced through improved fertilization measures.