Abstract: By using the CERES-Maize crop model and Century soil model in Decision Support System of Agrotechnology Transfer (DSSAT) model, this paper studied the effects of crop management parameters, fertilizer N application rate, soil initial N supply, and crop residue application on the maize growth, crop-soil N cycling, and soil organic C and N ecological balance in black soil (Mollisol) zone of Jilin Province, Northeast China. Taking 12000-15000 kg·hm^-2 as the target yield of maize, the optimum N application rate was 200-240 kg N·hm^-2. Under this fertilization, the aboveground part N uptake was 250-290 kg N·hm^-2, among which, 120-140 kg N·hm^-2 came from soil, and 130-150 kg N·hm^-2 came from fertilizer. Increasing the N application rate (250-420 kg N·hm^-2)induced an obvious increase of soil residual N (63-183 kg·hm^-2); delaying the N topdressing date also induced the increase of the residual N. When the crop residue application exceeded 6000 kg·hm^-2, the soil active organic C and N could maintain the supply/demand balance during maize growth season. To achieve the target maize yield and maintain the ecological balance of soil organic C and N in black soil zone of Jilin Province, the chemical N application rate would be controlled in the range of 200-240 kg N·hm^-2, topdressing N should be at proper date, and the application amount of crop residue would be up to 6000 kg·hm^-2.

Key words: DSSAT model, soil nitrogen cycling, sensitivity analysis, crop nitrogen uptake