Abstract:

To optimize the drip irrigation scheme and explore the effect of drip irrigation amount on the yield and quality of edible sweet potato under medium fertility conditions in Beijing, a field experiment was carried out in Taishizhuang Village Experimental Station of Taishitun Town in Miyun from 2021 to 2022. The conventional flood irrigation was used as the control (CK), 'Yanshu 25' variety was selected as test material, and six drip irrigation treatments with varying water volumes were set. The results showed that drip irrigation applied before transplanting, during root-establishing and seedling-slowdown stage, and branching and tuber-setting stage, with water volumes of 375-450 m³/hm², saved 25%-38% water compared to conventional irrigation. Within this irrigation range, the ratio of above-ground fresh weight to underground fresh weight (T/R) per plant was 0.6-0.7, the sweet potato yield reached 46881.5-47699.4 kg/hm² (54.0%-56.7% higher than that of conventional irrigation), and the commercial tuber yield was 42214.0-43271.6 kg/hm². Different treatments had minor effects on crude protein content, fresh fiber content and soluble sugar content of sweet potato, but relatively greater impacts on dry matter weight. The results approve that under the condition of medium fertility in Beijing, the drip irrigation amount of 375-450 m³/hm² in the key growth period of 'Yanshu 25' is a suitable irrigation scheme to achieve high yield and high efficiency. This scheme can significantly save water resources while ensuring yield and quality, and provide scientific basis for precise irrigation of sweet potato.

Key words: sweet potato, drip irrigation, irrigation amount, yield, water use efficiency, agronomic traits