晋南冬小麦—夏玉米轮作体系的氮肥运筹

Study on Nitrogen Fertilization in Rotation of Winter Wheat and Summer Maize in Southern Shanxi

冬小麦—夏玉米轮作是晋南的主要种植制度。通过田间小区试验,研究了冬小麦—夏玉米轮作体系内氮肥分配(控制氮肥总量420 kg/hm2)对作物产量、农学效率和纯收益及肥料利用率的影响。结果表明,冬小麦—夏玉米轮作体系内氮肥分配量及比例显著影响作物产量、纯收益和氮肥的效率,冬小麦季施总氮55%(231 kg/hm2)、夏玉米季施总氮45%(189 kg/hm2)时,可获得最高的轮作总产量(13 026 kg/hm2)和最大的净收益(22 146元/hm2),氮肥的农学效率和利用率较其他分配方式均有提高,是晋南地区冬小麦—夏玉米轮作氮肥分配的适宜比例。值得指出的是,由于作物生长期间受春寒和夏旱的影响,冬小麦—夏玉米轮作体系内的氮农学效率和氮肥利用率均较低,仅分别为4.6 kg/kg和20.8%。

The rotation of winter wheat and summer maize is a major planting system in southem Shanxi. This field experiment was conducted in a randomized design with four replicates to study the influence of nitrogen distribution on yield, net return, nitrogen agronomic efficiency and nitrogen use recovery in rotation of winter wheat and summer maize based on the amount of nitrogen controlled （420 kg/hm2）. The results showed that the proportion of nitrogen distribution significantly affected the yield, net return and nitrogen use efficiency in the rotation. Under the condition of 420 kg/hm2 nitrogen fertilization, the proportion of 55% （231 kg/hm2） applied on winter wheat and 45% （ 189 kg/hm2） for summer maize could help obtain the highest production （ 13 026 kg/hm2） and net return （22 146￥/hm2）, and the agronomic efficiency and recovery of nitrogen fertilizer was increased. This indicated that the proportion of nitrogen distribution in the rotation was feasible for southern Shanxi province. It was important to point out that as crop suffered from adverse weather at growth stage, it led low nitrogen agronomic efficiency and nitrogen use recovery with the average value only 4.6 kg/kg and 20.8%, respectively.