| To explore the impact of integrated technology of supplementary irrigation, nitrogen reduction, water and fertilizer on potato yield and water use efficiency, this study conducted an integrated potato water and fertilizer experiment in the central region of Gansu Province from 2022 to 2023. This experiment sets up four planting modes, including T1: Farmer's dry farming mode (W0N260): no irrigation and basal application of N fertilizer 260 kg N hm-2; T2: Cooperative high irrigation and high nitrogen fertilizer mode (W150N260): basal application of N fertilizer 260 kg N hm-2 and Irrigation 6 times during the growth period, with a total of 150 mm of irrigation; T3: Integrated water and fertilization treatment Ⅰ (W90FN102+98): basal application of N fertilizer 102 kg N hm-2 and drip fertilizer 98 kg N hm-2; T4: Integrated water and fertilization treatment Ⅱ (W90FN42+98), basal application of N fertilizer 42 kg N hm-2, drip fertilizer 98 kg N hm-2. The integrated water and fertilization treatments utilized an IoT smart irrigation machine during the growth period to control the surface soil moisture content of 0 ~ 20cm to not be less than 15.0%, with a total irrigation of 90 mm. The results showed that the integration of supplementary irrigation, nitrogen reduction, water and fertilizer significantly promoted the growth of leaf area index, aboveground and tuber dry matter accumulation, and significantly increased the weight of single potatoes and the rate of large potatoes (≥150 g). T2 treatment, the rate of dry matter accumulation in potatoes slows down in the later stages of growth. In 2022 and 2023, the potato tuber yield of T3 treatment increased by 100.9% and 229.4% respectively compared to T1 treatment, and increased by 30.4% and 38.5% respectively compared to T2 treatment; The potato tuber yield of T4 treatment significantly increased by 94.5% and 216.3% compared to T1 treatment in 2022 and 2023, respectively, and increased by 26.2% and 32.9% compared to T2 treatment. There was no significant difference in potato yield between T3 and T4 treatments; From 2022 to 2023, the WUE size order among all treatments was T3>T4>T2>T1 treatment; Compared with T1 treatment, T3 treatment increased by 46.9% and 148.1%, while T4 treatment increased by 43.9% and 136.8%, respectively; Compared with T2 treatment, T3 treatment increased by 50.7% and 55.9%, respectively; T4 treatment increased by 47.6% and 48.7%. The integration of water and fertilizer significantly improved the water use efficiency of potatoes. Moreover, under the same amount of topdressing nitrogen fertilizer, the yield of potatoes is not significantly affected by the amount of basal nitrogen fertilizer. Therefore, basal nitrogen fertilizer application of 42 kg N hm-2, supplementary irrigation of 90 mm during the growth period, and drip fertilizer application of 98 kg N hm-2 can be recommended as a high-yield and efficient production model for potatoes in semi-arid areas of central Gansu. |