Effects of Water and Nitrogen Coupling on the Economic Yield and Water and Nitrogen Use Efficiency of Cabbage

The study aimed to explore the effects of different water and nitrogen coupling on the economic yield, economic benefit, nitrogen use efficiency and water productivity of cabbage, in order to optimize the water and nitrogen management measures in the field of cabbage. By taking Cabbage Zhonggan No. 15 as the research object, two irrigation modes the conventional irrigation (W1), water-saving irrigation (W2, 70% of conventional irrigation) and four nitrogen application levels 0 kg·hm⁻² (N0), 119.94 kg·hm⁻² (N1), 239.88 kg·hm⁻² (N2), and 359.82 kg·hm⁻² (N3) were set to analyze the effects of different water and nitrogen coupling on the economic yield, economic benefit, nitrogen use efficiency and water productivity of cabbage. The results showed that: The nitrogen application rate and irrigation mode had significant effects on the economic yield, nitrogen use efficiency and water productivity of cabbage (P＜0.05). The economic yield and water productivity increased first and then decreased with the increase of nitrogen application rate. Under the same nitrogen application rate, the nitrogen use efficiency was higher under the water-saving irrigation mode. he economic yield, economic benefit and water productivity of cabbage treated with W2N2 were the highest, which were 16.11 t·hm⁻², 16544.73 yuan·hm⁻² and 4.88%, respectively, and significantly increased by 14.34%, 11.50% and 64.31% compared with W1N1 treatment, respectively. Therefore, the optimal water-nitrogen coupling mode for cabbage formation was as follows: 330 t·hm⁻² of irrigation amount and 239.88 kg·hm⁻² of nitrogen application amount under the water-saving irrigation mode. The appropriate and moderate water-nitrogen coupling mode had the potential of increasing the production, high efficiency and water saving.