Field experiments were conducted to study the effect of different nitrogen application rates on maize yield, nitrogen uptake and utilization under different soil fertilities in Jilin province. The results showed that, the highest N application rates under maximum yields were N 251 and 206 kg/ha for Fanjiatun and Yushu respectively,and the economic optimum N application rates under economic optimum yields were N 227 and 134 kg/ha for Fanjiatun and Yushu respectively. The maximum N absorption rate and total N uptake were significantly improved with the increasing N application rates, and the date of the maximum N absorption rate occurred earlier in Fanjiatun site. The residual nitrate nitrogen in 0 -30 cm soil profile increased with N application rates, and nitrate accumulation in 0-30 cm soil profile was observed higher in Yushu than that in Fanjiatun. The nitrogen agronomic efficiency, nitrogen recovery efficiency and nitrogen partial factor productivity in Fanjiatun with lower soil fertility were higher than those in Yushu with higher soil fertility. In summary, it was suggested that for the site like Fanjiatun with lower soil fertility, the high yield could be reached by increasing N application rate, while for the site like Yushu with higher soil fertility, N application rate should be controlled in order to increase the yield and improve N use efficiency.%采用田间试验,研究了吉林省高、低肥力条件下不同氮肥用量对春玉米产量及氮素吸收和利用的影响.结果表明,范家屯和榆树试验点的最高产量施氮量分别为N 251和206 kg/hm2,最佳经济施氮量分别为N 227和134kg/hm2.两试验点的最高产量和最佳经济产量均表现为范家屯试验点高于榆树试验点.适宜增加施氮量可显著提高范家屯低肥力试验点玉米氮素最大吸收速率和吸收总量,提前最大吸收速率出现的天数.玉米收获后0-30cm土层残留的硝态氮呈现出随着施肥量的增加而增加的趋势,其中榆树高肥力试验点土壤硝态氮积累明显高于范家屯低肥力土壤.范家屯低肥力试验点氮素的农学利用率、表观回收率和偏因子生产力高于榆树高肥力试验点.范家屯低肥力条件下可通过增施氮肥提高产量;而榆树高肥力条件下则可通过控制氮肥用量达到提高产量和氮肥利用率的双重目标.
展开▼
