氮密调控对冬小麦籽粒产量及氮素利用效率的影响

为探究氮肥用量和种植密度对冬小麦籽粒产量和氮素利用效率的互作效应,2017—2018年在大田定位试验条件下,以‘矮抗58’为试验材料,设置112.5、150、187.5 kg/hm² 3个种植密度,0、180、240、300 kg/hm²4个施氮水平,研究了氮肥用量和种植密度对小麦干物质积累转运、籽粒产量及氮素利用效率的影响。结果表明,同一种植密度下,花后贮藏干物质的转运量及对籽粒产量的贡献率随施氮量的增加呈先升后降趋势,而花前趋势相反;冬小麦群体分蘖数、穗数、穗粒数和产量随施氮量的增加呈升高趋势,然而千粒重和氮肥利用效率随施氮量的增加呈降低趋势。可以通过提高种植密度来减小施氮量降低对小麦产量和氮素利用效率的负面影响。因此,适宜氮肥用量与种植密度可提高小麦籽粒产量和氮素利用效率。在本试验条件下,施氮量240 kg/hm²与种植密度150 kg/hm²相匹配是获得更高产高效的最优组合。

The Effect of Density and Nitrogen Fertilizer on Wheat Yield and Nitrogen Use Efficiency of Winter Wheat

The paper aims to explore the interaction effects of nitrogen application rate and planting density on yield and nitrogen use efficiency of winter wheat. Under the condition of field positioning experiment in 2017 and 2018, ‘Aikang 58’ was used as experimental material to study the effects of planting density and nitrogen application rate on dry matter accumulation and transport, yield and nitrogen use efficiency of wheat, with three sowing densities of 112.5, 150 and 187.5 kg/hm² and four nitrogen application levels of 0, 180, 240 and 300 kg/hm². The results showed that under the same sowing density, the transport amount of dry matter stored after anthesis and its contribution rate to grain yield increased first and then decreased with the increase of nitrogen application level, while the trend before anthesis was opposite; the population tiller number, spike number, grain number per spike and yield of winter wheat increased with the increase of nitrogen application level, but the thousand seed weight and nitrogen use efficiency decreased with the increase of nitrogen application level. In addition, the negative effects of reducing nitrogen application rate on wheat yield and nitrogen use efficiency could be offset by increasing planting density. Therefore, the reasonable combination of nitrogen application rate and planting density can improve wheat yield and nitrogen use efficiency. The recommended nitrogen application rate for winter wheat is 240 kg/hm² and the planting density is 150 kg/hm².