基于DSSAT模型的吉林省黑土作物-土壤氮循环和土壤有机碳平衡

应用DSSAT模型中的CERES-Maize作物模型和Century土壤模型,分析了作物管理参数、施肥量、土壤初始氮含量和作物桔杆还田对吉林省黑土地区玉米生长、氮循环以及有机碳氮生态平衡的影响.结果表明:在玉米目标产量为12000～15000kg.hm-2条件下,最佳施氮肥量为200～240kgN.hm-2.在该氮肥用量下,玉米地上氮吸收量为250～290kgN.hm-2,其中,120～140kgN.hm-2来自土壤,130～150kgN.hm-2来自肥料;提高氮肥用量(250～420kgN.hm-2)将导致土壤残留氮明显增加(63～183kgN.hm-2);延迟追肥时间同样导致土壤残留氮增加;当玉米秸杆还田量超过6000kg.hm-2时,模拟的土壤活性有机碳、氮可以维持当年的供需平衡.建议在吉林省中部地区黑土玉米带,化肥施氮量控制在200～240kgN.hm-2,适时追肥,秸杆还田量在6000kg.hm-2以上,以确保高产和维持土壤养分生态平衡.

Crop-soil nitrogen cycling and soil organic carbon balance in black soil zone of Jilin Province based on DSSAT model

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 12,000-15,000 kg x hm(-2) as the target yield of maize, the optimum N application rate was 200-240 kg N x hm(-2). Under this fertilization, the aboveground part N uptake was 250-290 kg N x hm(-2), among which, 120-140 kg N x hm(-2) came from soil, and 130-150 kg N x hm(-2) came from fertilizer. Increasing the N application rate (250-420 kg N x hm(-2)) induced an obvious increase of soil residual N (63-183 kg x hm(-2)); delaying the N topdressing date also induced the increase of the residual N. When the crop residue application exceeded 6000 kg x 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 x hm(-2), topdressing N should be at proper date, and the application amount of crop residue would be up to 6000 kg x hm(-2).