不同氮肥管理对吉林春玉米生长发育和养分吸收的影响

针对吉林春玉米氮肥施用中存在氮肥用量偏大，且具盲目性的现状，采用田间试验研究农民习惯施氮量和推荐施氮量下氮肥不同施用方式对春玉米干物质积累、子粒产量、氮素吸收和利用效率的影响。结果表明，推荐施氮量下，苗期和灌浆期春玉米干物质积累量显著高于习惯施肥，有机无机配合提高了春玉米干物质积累速率。施氮处理与不施氮相比均显著增加玉米子粒产量，增产11.2%～16.8%; 推荐施氮量下玉米子粒产量与习惯施氮量相当，但显著提高氮素的偏因子生产力和农学效率。在氮磷钾用量一致的基础上，用30%有机肥氮替代化肥氮与100%化肥氮处理的产量相当，对氮素利用效率也没有影响，并降低收获期土壤无机氮含量。说明合理施用氮肥不但能够维持玉米产量，还可减少氮肥投入，提高氮肥利用效率；有机肥部分替代化肥氮是吉林春玉米氮素管理的有效途径之一。

Maize growth and nutrient uptake as influenced by nitrogen management in Jilin province

Aimed to the current problem of fertilizer application in Jilin province, e.g. excessive fertilization, one time fertilization, fewer or no use organic manure, and the lower fertilizer use efficiency, a field experiment was conducted to study the effects of various nitrogen managements in traditional and recommended nitrogen rate on growth, yield and nutrient uptake of maize. Results showed that dry matter accumulation of maize in seedling stage and grain filling stage was significantly increased under recommended nitrogen rate compared to under traditional farmer's practice. Dry matter accumulation rate was improved when fertilizer nitrogen was applied combined with organic manure. All the treatments with nitrogen applied significantly increased grain yield by 11.2%-16.8% compared with control without nitrogen application. Although nutrient managements under the recommended nitrogen rate produced similar grain yields to those of farmer's practices, partial factor productivity and agronomic efficiency of nitrogen were significantly improved. On the basis of the same amount of N, P and K, fertilizer nitrogen substitution by pig manure produced similar yield and nitrogen use efficiency and resulted in lower soil inorganic nitrogen compared with full chemical nitrogen applications. In summary, rational application of nitrogen fertilizer could not only sustain maize yield, reduced nitrogen input and also improved N use efficiency. Part of nitrogen substitution by organic manure may be a feasible way in nutrient management on spring maize in Jilin.