氮肥运筹和播种密度对晚播小麦群体总茎数及产量的影响

Effects of Nitrogen Application and Density on Population Dynamics and Yield of Late-sown Wheat

为给安徽淮北地区晚播小麦的高产高效栽培提供技术支撑,以近年来淮北地区主导小麦品种济麦22为试验材料,研究了淮北地区晚播条件下不同氮肥运筹和播种密度对小麦群体总茎数、产量及其构成要素的影响。结果表明,不同播种密度下晚播小麦群体的总茎数变化一致,呈明显的单峰变化趋势,除返青期外,总茎数均以基本苗525万/hm2(以D525表示,下同)处理最大;晚播小麦的籽粒产量以D450最高,为8 823.3 kg/hm2,但不同密度间的产量差异不显著;进一步分析表明,随着播种密度的增加,穗数升高,穗粒数降低,千粒质量变化不明显;不同氮肥运筹方式下晚播小麦群体总茎数的变化与不同密度处理表现趋同,即亦呈单峰变化趋势,同时适当延迟氮肥追施时间有助于稳定晚播小麦生育后期的群体总茎数;不同氮肥运筹间晚播小麦的穗粒数、生物学产量、经济系数的差异均未达到显著水平,但籽粒产量以基追比为4∶6(孕穗期)处理最高,为8 618.0 kg/hm2,除与10∶0(基施)处理间差异显著外,与其他施肥处理间的差异并未达到显著水平。

With a medium gluten wheat variety Jimai 22 as the test material,a field experiment was carried out at Mengcheng of Anhui Province to study the effects of nitrogen application and density on the all stems and yield of late-sown wheat. The amount of all stems of the tested variety under different densities were all increased after emergence,reached the highest at jointing stage,and decreased afterwards,showing single peak curves for all densities, and the treatment of D525has the largest stems at all growth stages expect seedling. The D450has the highest grain yield,being 8 823. 3 kg / ha,while no significant difference compared with other densities. With the increase of planting density,grain number per spike decreased,spike number increased,but no obvious change on 1000-grain weight. The number of all stems changed in different nitrogen applications was the same as densities; appropriate delaying nitrogen topdressing time contributes to the stability of late-sown wheat stems. The differences among different nitrogen applications of late-sown wheat spike number,biological yield,economic coefficient were not significant,but the grain yield of 4∶ 6（ Booting stage） treatment was the highest,being 8 618. 0 kg / ha,which showed no significant difference with others but the exception of 10∶ 0（ Basal） treatment.