春季追肥对冬小麦群体构建和籽粒灌浆进程的影响

为明确冬小麦春季合理追肥技术,以追肥时间（返青后10、25和40d）为主区,追肥量（90、120和150kg/hm²）为副区,研究春季追肥对冬小麦群体分蘖动态变化、籽粒灌浆进程、产量及氮效率的影响。结果表明,返青后25d较其他追肥时间显著提高了开花期分蘖数,追氮量为120kg/hm²时最高。返青后25d较其他追肥时间显著提高了籽粒灌浆起始势,籽粒达最大灌浆速率时间提高了1%~20%,提高灌浆过程中快增期和缓增期的灌浆速率,追氮量以120kg/hm²表现最好。返青后25d较其他追肥时间显著提高了成熟期植株干物质量及穗部结实性状,穗数、穗粒数、千粒重和产量分别提高8%~11%、7%~12%、3%~5%和8%~30%,且显著提高了氮肥偏生产力,以追氮量120kg/hm²最高。总之,返青后25d追肥可有效调控冬小麦春季分蘖消长,增加有效穗数,促进籽粒灌浆,提高粒重,且追施氮120kg/hm²实现了产量和氮效率同步提高。

Effects of Topdressing in Spring on Population Construction and Grain Filling Process of Winter Wheat

To clarify the reasonable topdressing technology in spring, the effects of topdressing time (10, 25, 40d after returning to green) and amount (90, 120, and 150kg/ha) on tiller dynamics, grain filling process, yield, and nitrogen efficiency of winter wheat population were studied. The results showed that 25d after returning to green, topdressing significantly increased the number of tillers at the anthesis stage compared with other times, and the topdressing amount of 120kg/ha was the highest. Compared with other times, topdressing at 25d after returning to green significantly increased the initial grain filling potential, increased the time to reach the maximum grain filling rate by 1%-20%, increased the grain filling rate at the rapid and slow grain filling stages, and the topdressing amount of 120kg/ha was the best. Compared with other times, topdressing at 25d after returning to green significantly improved the dry matter quality of the plant at the mature stage and seed setting characters of the spike especially increased the number of the spike, grain number of per spike, 1000-grain weight, and grain yield by 8%-11%, 7%-12%, 3%-5%, and 8%-30%, respectively, and significantly increased the partial factor productivity of nitrogenous fertilizer, the topdressing amount of 120kg/ha was the best. In conclusion, topdressing at 25d after returning to green could effectively regulate and control the growth and decline of winter wheat tillers in spring, increase the number of effective spikes, promote grain filling rate, increase grain weight, and topdressing amount of 120kg/ha could achieve the simultaneous improvement of yield and nitrogen efficiency.