Application of the DNDC model to estimate N2O emissions under different types of irrigation in vineyards in Ningxia, China.

Furrow irrigation, which can be combined with fertilisation by dissolving solid fertilisers in irrigation water, is the most common practice in vineyards in the Ningxia Hui Autonomous Region, and drip irrigation and fertigation have been employed in some areas. These irrigation methods and their corresponding fertilisation schemes may affect nitrous oxide (N 2 O) emissions from the soil. Therefore, it is important to use a model to simulate differences in N 2 O emissions and identify farmland management methods that limit N 2 O emissions. During the July–August 2012 and July–September 2013 growing seasons, the denitrification and decomposition (DNDC) model was tested against experimental N 2 O emissions data from vineyards in Yuquanying, Yongning, Yinchuan, Ningxia. After model validation, the simulated differences in emissions between furrow irrigation and drip irrigation were 9.86 ± 0.845 and 0.966 ± 0.464 kg ha −1 a −1 in 2012 and 2013, respectively. Thus, the emissions were reduced by approximately 72.5% and 52.4% in 2012 and 2013. In the regional simulation, the Global Warming Potential (GWP) of the annual N 2 O emission reductions reached 27,749,760 ± 5,489,160 kg CO 2 -equivalents after the vineyards in the Ningxia Autonomous Region were converted from furrow irrigation to drip irrigation. In conclusion, the DNDC model, which proved to be a powerful tool for addressing the efficacy of alternative management practices in vineyards, revealed that N 2 O emissions can be reduced by adopting drip irrigation systems rather than traditional furrow irrigation systems. [ABSTRACT FROM AUTHOR]