With the aim of investigating the effects of biochar and nitrogen input on the season variation of carbon dioxide (CO₂), methane (CH₄) fluxes，we measured CO₂ and CH₄ cumulative emission, CO₂+ CH₄ emission intensity in dry farmland. A field experiment was performed over two years to measure CO₂ and CH₄ emissions by continuous observation using static chamber technique. Soil temperature and moisture were also measured at the same time. Three treatments were laid out with three replicates per experiment: C₀N₀ (no biochar, no N), C₀N₁ (no biochar, 225 kg·hm^-2), C₁N₁ (50 t·hm^-2 biochar, 225 kg·hm^-2). The results showed that：（1） the dry spring maize farmland was source for CO₂ under three treatments during the experimental period. The rates of CO₂ emission increased and peaked on the 22th June 2014 and the 1st July 2015 during the maize growing season. The rates then decreased and were maintained at a relatively low level during the fallow season. Biochar and nitrogen amendments decreased the CO₂ flux and cumulative CO₂ emission during the maize growing season. （2）The flux and cumulative CO₂ emission were significantly lower in C₁N₁ treatment than that in C₀N₀ treatment during the two spring maize growing seasons. （3）There was significantly positive correlation between CO₂ flux and soil temperature. Both exponential equation and quadratic equation could be used to simulate the relationships, of which the correlation of 10 cm temperature was better than of 0 cm temperature. The CO₂ flux had negative correlation with soil moisture. （4）The CH₄ flux was between -16.08-73.96 μg·m^-2·h^-1 for all of the treatments, and was sink for CH₄ . Biochar and nitrogen amendments increased the CH₄ flux and cumulative CH₄ emission during the maize growing season which were also affected by annual environmental factors. The CH₄ emission had positive correction with soil moisture but negative with soil temperature. The addition of biochar and nitrogen could reduce CO₂ and increase CH₄ fluxes and cumulative emission from dry farmland. Comprehensive consideration of two aspects, a reasonable addition of nitrogen and biochar would be beneficial for controlling greenhouse gas emission from dry farmland. Briefly, biochar and nitrogen amendment significantly increased the yield of maize, while reduced CO₂+CH₄ emissions intensity significantly.