Journal of Integrative Agriculture

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优化种植密度和氮肥施用可降低稻茬晚播小麦产量损失并提高籽粒品质

  

  • 修回日期:2024-03-06

Optimizing planting density and nitrogen application to mitigate yield loss and improve grain quality of late-sown wheat under rice-wheat rotation

Zhongwei Tian, Yanyu Yin, Bowen Li, Kaitai Zhong, Xiaoxue Liu, Dong Jiang, Weixing Cao, Tingbo Dai#   

  1. Key Laboratory of Crop Physiology Ecology and Production Management of Ministry of Agriculture and Rural Affairs, College of Agrivulture, Nanjing Agricultural University, Nanjing 210095, China

  • Revised:2024-03-06
  • About author:Correspondence Tingbo Dai, Tel: +86-25-84395033, E-mail: tingbod@njau.edu.cn

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摘要： 晚播是制约稻茬小麦高产优质的关键因子，探明晚播小麦高产优质协同的生理基础及调控途径，将为晚播小麦高产优质栽培提供理论和技术支撑。两年的田间试验研究了播期、施氮量和种植密度对稻茬小麦产量、品质和群体特征的影响及其生理基础。结果表明，播期、种植密度和施氮量在调控小麦产量和品质方面存在显著的互作效应。晚播小麦产量降低主要归因于单位面积穗数和穗粒数的减少，但增加施氮量和种植密度可弥补晚播导致的产量损失。籽粒蛋白质含量和湿面筋含量随播期推迟和施氮量增加而提高，但随种植密度增加而降低。晚播小麦要达到9000和7500 kg ha-1以上的目标产量，则最晚播期分别不能迟于11月4日和11月15日；且需满足最大茎蘖数、最大叶面积指数、开花期干物质积累量分别达到150和100万ha-1、6.7和5.5、14000和12000 kg ha-1以上。晚播10和20天高产优质协调的最佳氮肥和密度组合分别为N300D225和N300D375。最佳组合处理下的小麦开花后具有较高的净光合速率、硝酸还原酶、谷氨酰胺合成酶和谷丙转氨酶活性及较低的糖/氮比，这是晚播小麦高产优质协同的重要生理基础。

Abstract: Late sowing is a critical factor that hinders achieving high-yield, good-quality wheat under rice-wheat rotation.  Understanding the physiological basis and regulatory pathways that lead to late-sown wheat of high yield and good quality is crucial for developing effective cultivation strategies.  A 2-year field experiment was conducted to investigate the effects of sowing date, nitrogen (N) application rate, and planting density on wheat yield, grain quality, population characteristics, and the underlying physiological factors.  The results revealed significant interactions among the sowing date, planting density, and N application in regulating both yield and quality. Late sowing reduced grain yield primarily by reducing the number of spikes and kernels.  However, the latter was improved by increasing N application and the planting density, thus mitigating the yield losses caused by late sowing.  Moreover, the grain protein content (GPC) and wet gluten content (WGC) increased with delayed sowing dates and higher N rates, but decreased with increased planting densities.  For wheat yields over 9,000 or 7,500 kg ha–1, the latest sowing date should not be later than Nov. 4 or 15, respectively.  In addition, specific criteria should be met, including a maximum of 1.5 and 1.0 million stems and tillers ha–1, a maximum leaf area index of 6.7 and 5.5, and a dry matter accumulation (DMA) at anthesis of 14,000 and 12,000 kg ha–1, respectively. For high-yield, good-quality late-sown wheat, the optimal combination is a 25% increase in the N rate (300 kg N ha–1) and a planting density of 2.25 million (N300D225) or 3.75 million (N300D375) plants ha–1 for 10- or 20-day delays in sowing, respectively.  These combinations result in higher leaf net photosynthetic rate; higher activities of leaf nitrate reductase, glutamine synthetase, and grain glutamic pyruvic transaminase; and a lower sugar-N ratio during post-anthesis.

Key words: wheat grown after rice , late sowing ,  , planting density ,  , nitrogen application rate ,  , grain yield ,  , grain quality