Abstract: 【Objective】 To investigate the effects of partial substitution of conventional chemical fertilizer with different proportions of organic fertilizer on potato yield and apparent nitrogen loss.【Methods】 Using potato variety V7 as experimental material,six treatments were established in 2023 and 2024：no nitrogen fertilizer （CK）,conventional chemical fertilizer alone （CF）,and chemical fertilizer substituted by 20%（OF1）,40%（OF2）,60%（OF3）,and 80%（OF4） organic fertilizer. Differences in soil nitrogen content in the plough layer（0-30 cm）,potato biomass,nitrogen content,nitrogen uptake,yield,agronomic nitrogen use efficiency,and apparent nitrogen loss were analyzed under different treatments.【Results】 During the tuber bulking stage,the soil nitrate nitrogen content in the plough layer under OF1 treatment was significantly increased by 26.22%-39.48% compared to the CF treatment（P<0.05）;at mature stage,the soil ammonium nitrogen content was significantly increased by 32.81%-77.78% compared to CF treatment （P<0.05）. From the tuber bulking stage to mature stage of potato,the biomass,nitrogen content,and nitrogen uptake under the OF1 treatment were increased by 7.45%-33.10%,0.17-0.58 percentage points,and 42.29%-53.20%,respectively,compared to the CF treatment. Over the two years,the potato yield under the OF1 treatment was increased by 6.71%-10.61% compared to the CF treatment;the agronomic nitrogen use efficiency and partial factor productivity of nitrogen fertilizer for the OF1 treatment were 132.39,138.69 kg/kg,and 263.85,257.45 kg/kg,respectively,both significantly higher than the CF treatment（P<0.05）;the apparent nitrogen loss under the OF1 treatment was reduced by 34.64% and 23.65%,respectively,compared to the CF treatment.【Conclusion】 Substituting chemical fertilizer with 20% organic fertilizer can significantly increase potato yield and agronomic nitrogen use efficiency,and reduce apparent nitrogen loss.

Key words: Potato, Organic fertilizer, Yield, Agronomic nitrogen use efficiency, Apparent nitrogen loss