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为了给河西走廊灌区春玉米的氮素管理提供理论依据,用田间试验方法于2006—2007年研究了不同氮水平下春玉米干物质积累和氮素吸收利用动态的规律。采用自然风干法和微量凯氏定氮法测定植株干重和氮素含量。结果表明:1)不同氮水平下春玉米干物质积累与其氮素的吸收均可以用logistic方程(Y=K/(1+ea+rt)拟合;2)施氮肥可显著影响到春玉米干物质最大积累速率和氮素最大吸收速率,前者N在225 kg/hm2处理下最高,为644.6 kg/(hm2.d),后者N在300 kg/hm2处理下最高,为5.1 kg/(hm2.d);3)施氮肥对春玉米干物质最大积累速率和氮素最大吸收速率出现的天数均无规律性变化,前者平均为92.5 d,后者平均为78.1 d,后者比前者出现平均提前了15 d左右;4)随着施氮量增加,春玉米氮素吸收效率增加,于出苗后110 d达到最大吸收率,到成熟期有所下降;而其利用率随着施氮量增加而降低,随着玉米生长而增加,至玉米成熟期达到峰值。
In order to provide a theoretical basis for nitrogen management of spring maize in the irrigation area of Hexi Corridor, field experiments were conducted to study the dynamics of dry matter accumulation and nitrogen uptake and utilization of spring maize at different nitrogen levels from 2006 to 2007. The dry weight and nitrogen content of plant were determined by natural air-drying method and micro Kjeldahl method. The results showed that: 1) The dry matter accumulation and nitrogen uptake of spring maize under different nitrogen levels could be fitted by logistic equation (Y = K / (1 + ea + rt); 2) The maximum N accumulation rate and the maximum nitrogen uptake rate of N were highest at 225 kg / hm2 and 644.6 kg / (hm2.d) respectively, while N was the highest under the treatment of 300 kg / hm2 at 5.1 kg / (hm2) .d); 3) There was no regular change in the maximum accumulation rate of dry matter and the maximum nitrogen absorption rate of spring maize, with an average of 92.5 days for the former and 78.1 days for the latter, with the latter showing an average 15 days ahead of schedule. 4) With the increase of N application rate, the nitrogen uptake efficiency of spring maize increased to the maximum at 110 days after emergence and decreased to the mature stage; while the utilization rate increased with the increase of N application rate While decreasing, increasing with the growth of maize, reaching the peak of maize maturity.