氮肥后移对冬小麦产量、氮肥利用率及氮素吸收的影响

Effect of postponing N application on the yield,apparent N recovery and N absorption of winter wheat

为改变小麦"一炮轰"施肥存在的弊端,通过两个田间试验,研究了不同氮肥后移模式对冬小麦产量、氮肥利用率及氮素吸收、累积的影响,旨在了解冬小麦对氮素吸收和转运规律,为实现冬小麦超高产和合理施肥提供依据。结果表明,与传统"一炮轰"施肥技术相比,氮肥后移可以提高冬小麦的子粒产量、穗数及氮肥利用率,以N4处理(50%作为基肥,50%返青后追施)最高,两个试验点产量分别达到3857和8240kg/hm^2,增产25.8%和17.3%,穗数增加6.0%和18.1%,氮肥利用率提高111.8%和107.4%。冬小麦氮素累积主要集中在返青后期至灌浆期阶段,因此在保证基肥的条件下,返青期后追施氮肥显得尤为重要。表明在本试验条件下,比较合理的氮肥施肥模式为50%作为基肥,50%返青后追施。

Two field experiments were carried out to study the effect of postponing N fertilizer application on the yield, apparent N recovery and N absorption of winter wheat. The objective of this experiment was to find the pattern of N absorption and transformation, and to give a scientific suggestion for high-yield management and optimized N application of winter wheat. The results showed that postponing N fertilizer application can increase grain yield, number of spike and apparent N recovery of winter wheat, with treatment N4 （50% basal fertilizer, 50% application in stem elongation stage） having the best results. The yield of two field experiments reached 3857 and 8240 kg/ha, increased yield by 25.8 % and 17.3%, spike number by 6.0% and 18.1%, apparent N recovery by 111.8% and 107.4%, respectively. The majority of N absorption and accumulation in winter wheat took place from regreening to filling, so on the basis of basal fertilizer application, it is very important to apply N fertilizer after regreening. Based on results from this experiment, it is recommended that 50 % of N fertilizer should be applied as basal fertilizer and 50 % should be applied after regreening.