Received: Sep 03, 2020 / Published: Dec 31, 2021
Crop management practices in intensive vegetable production can influence nitrous oxide (N2O) emissions from soils. This study quantified seasonal N2O emissions and N2O emission intensities, and investigated the factors driving emissions in different vegetable management practices. Emissions from four typical vegetable crops (two choy sums, a mustard, and a cabbage) were intensively measured over the 2016 autumn season on farms in Van Noi and Dang Xa communes in the Hanoi peri-urban area. Different N2O emissions were observed in the four leafy vegetable crops. The average daily emissions varied from 12.15 g to 40.08 g N2O-N ha-1 and the autumn season N2O emissions varied from 1.13 kg to 8.45 kg N2O-N ha-1 across the four crops. The greatest daily and season emissions were from cabbage, and the lowest were from mustard. Emission intensities varied among the types of vegetables and was the lowest at the mustard farm (37 kg CO2-e t-1), indicating that the crop management practices increased the mustard yield but retained a low N2O emission rate. Practices responsible for high N2O emissions were overuse of nitrogen fertilisers and furrow irrigation. An improvement in the farmers’ adoption of best practices in fertiliser application and irrigation could reduce N2O emissions without affecting crop productivity.
