To explore the response of silage maize production and soil erosion on sloping farmland to nitrogen input reduction，set N1 (300.00 kg/hm²)，N2 (225.00 kg/hm²)，N3 (150.00 kg/hm²)and N4 (75.00 kg/hm²)on 10°sloping farmland 4 different nitrogen input treatments.The results showed that the average plant height，leaf area index and yield of silage maize treated with N1 and N2 were significantly higher than those of N3 and N4 (P<0.05).On the contrary，the root biomass and root / shoot ratio of silage maize increased with the decrease of nitrogen input.For soil erosion，the total runoff of N1 and N2 treatments was significantly lower than that of N3 and N4 treatments.Similarly，the sediment yield of N1 and N2 treatments was significantly lower than that of N3 and N4 treatments (P<0.05).Moreover，there was a significantly negative correlation between plant height and root biomass，but a significantly positive correlation between plant height and leaf area index.The leaf area index and plant height of maize were negatively correlated with surface runoff and sediment yield.In summary，nitrogen input can affect the aboveground agronomic traits and root biomass distribution of silage maize，and then affect the runoff and sediment yield on red soil slope farmland.It shows that the moderate reduction of 25% nitrogen input based on the local fertilization level will not significantly reduce corn yield，nor will it aggravate soil erosion.Therefore，this study provides an important theoretical basis for a better understanding of the response of soil erosion and agricultural production to nitrogen input in sloping farmland.