Characteristics of n absorption, utilization and optimum n-fertilizer rate based on a long-term fertilization experiment of oats | 燕麦氮吸收利用特性与适宜施氮量的定位研究

Chinese. 目的明确燕麦对氮的吸收利用特性以及吉林白城地区适宜氮肥用量。方法以皮燕麦白燕7号和裸燕麦白燕2号为材料，通过设置5个氮肥梯度（0、30、60、90和120 kgN#8226;hm-2），定位研究了两种燕麦氮吸收利用与产量形成的氮肥效应。结果本试验条件下，施氮量越多，燕麦不同生育阶段的氮积累量、总氮积累量、穗部氮积累量、转移量和花后吸收量越多，各处理间差异显著。氮素阶段吸收比例在低氮处理有苗期提高、灌浆后期降低的趋势，花前氮素转移率则表现为随施氮量增加先升高后降低。氮肥表观利用率、氮肥农学效率随施氮量的增加而降低。氮收获指数以中低施肥处理最高，不施肥或最高施氮处理最低。氮生理利用效率存在极显著的年际间差异，年份与品种互作效应显著。氮肥显著影响燕麦产量（P＜0.05），两种燕麦籽粒产量均随施氮水平的提高而增加，但90和120 kgN#8226;hm-2处理间差异不显著；获得最高产量的氮肥用量有随定位时间的延长而增大的趋势。结论施氮量显著影响燕麦对氮素的吸收与利用特性，品种间有差异，白燕7号较白燕2号对氮反应更敏感。4年的定位结果看，吉林白城地区氮肥用量90 kgN#8226;hm-2可以实现燕麦高产高效生产。

English. ObjectiveThe objective of this paper was to clarify the characteristics of N absorption and utilization, and determine the optimum N-fertilizer (NF) rate in oats in Baicheng, Jilin province. MethodHusked oat cultivar Baiyan 7 and naked oat cultivar Baiyan 2 were used and five NF rates (0, 30, 60, 90 and 120 kgN#8226;hm-2) were designed, a long-term fertilization experiment in which the NF rate in each plot was kept the same as its original designed amount throughout the research period was conducted in a randomized block design.ResultN amount (NA) accumulated in different growing periods or in the whole life, NA accumulated in panicle, NA transferred from vegetative organ to grain and NA absorbed after anthesis increased with the increase of NF rate, and there was a significant difference among the NF treatments. The percentage of NA accumulated in seedlings was higher but lower in late grain filling stage in no or lower NF treatment. The rate of N transferred from vegetative organ ascended firstly and then descended with the increase of NF rate. Apparent NF recovery efficiency and agronomic efficiency of applied NF declined with the increase of NF rate. The maximum N harvest index was observed in lower or medium NF treatment, and the minimum in no or the highest NF treatment. There was a significant interannual difference in N physiological use efficiency, and a significant interaction between year and cultivar was also found. N fertilization increased oats grain yield significantly (P＜0.05), but there was no significant difference between the treatments of 90 kgN#8226;hm-2 and 120 kgN#8226;hm-2. The NF rate at which the highest grain yield was harvested increased year by year in the continuous in-situ study. ConclusionThe characteristics of N absorption and utilization of oats was significantly affected by N fertilization, and there was a difference between the two cultivars. Baiyan 7 was more sensitive than Baiyan 2 in response to NF rate. A high-yielding and high N use efficiency production of oats could be achieved at the N rate of 90 kg#8226;hm-2 in Baicheng, Jilin province.