播期调整对陇东黄土高原春玉米产量及品质影响

Effects of Sowing Date Adjustment on Spring Maize Yield and Quality in the Loess Plateau of Eastern Gansu

  • 摘要: 基于2022—2024年甘肃省庆阳市西峰农业气象试验站春玉米分期播种试验, 在品种、土壤及栽培管理一致条件下, 分析播期差异引发的光、温、水资源配置变化对春玉米生长发育、物质积累、产量及籽粒品质的调控效应。结果表明:播期调整显著改变春玉米发育进程与气候资源配比, 随播期推迟, 发育期时长缩短, 全生育期平均气温升高, 降水量与日照时数减少, 光温水匹配格局重塑调控植株生长节奏;播期通过改变灌浆速率与干物质积累动态调控产量形成, 其中推迟播种10 d处理产量最优, 早播处理因苗期光温水配比失衡, 干物质积累不足导致产量受限;气象要素对产量的影响存在阶段特异性, 全生育期活动积温、平均气温和降水量与产量呈正相关, 七叶-拔节期、乳熟-成熟期为春玉米光温水响应关键敏感期;播期显著调控籽粒氨基酸、淀粉、脂肪合成积累, 降水量主导脂肪积累与氨基酸组成, 温度主要调控淀粉和脂肪合成。

     

    Abstract: To clarify response rules of spring maize yield and grain quality to climate change in the Loess Plateau of eastern Gansu and optimize the high-yield and high-quality cultivation technology system for local spring maize, field experiments of spring maize with different sowing dates conducted at Xifeng Agrometeorological Experimental Station from 2022 to 2024 are adopted in this study. Under identical test varieties, soil conditions and cultivation management measures, regulating effects of variations in light, temperature and water resources caused by different sowing dates on growth process, grain-filling dynamics, dry matter accumulation, yield components and grain quality of spring maize are systematically analyzed. Key meteorological limiting factors for spring maize production and the regulation mechanism of optimal sowing date in rain-fed agricultural areas in the Loess Plateau of eastern Gansu are determined. Results show that the growth process of spring maize and the allocation of light, temperature and water resources are significantly altered by sowing date adjustment. With the delay of sowing date, the duration of growth period is shortened, the average air temperature at each growth stage is increased, while the total precipitation and sunshine hours during the whole growth period are decreased. The growth rhythm of maize is further affected by the changed matching pattern of light, temperature and water. Yield formation is affected by sowing date through regulating grain-filling rate and dry matter accumulation. The highest yield is obtained in the treatment with sowing date delayed by 10 d (Treatment B2). Insufficient dry matter accumulation is observed in the early sowing treatment (Treatment B1) due to the uncoordinated allocation of light, temperature and water at the seedling stage. Effects of meteorological factors on yield are stage-specific. Yield is positively correlated with precipitation, accumulated temperature above 0 ℃ and average temperature throughout the growth period. Stages from seven-leaf stage to jointing stage and from milk-ripening stage to maturity stage are identified as the most sensitive periods of maize responding to light, temperature and water factors. Grain quality formation is also significantly affected by sowing dates, and contents of tyrosine, cystine, glutamic acid and other components are obviously changed. Precipitation is regarded as the core climatic factor regulating fat accumulation and amino acid composition, while temperature mainly dominates the synthesis of starch and fat. In this study, response mechanisms of yield and grain quality of spring maize to sowing-date-induced variations in meteorological factors in the Loess Plateau of eastern Gansu are elucidated. Key theoretical basis and technical support are provided for rational sowing arrangement, stress resistance, stable yield and high-efficiency quality cultivation of spring maize in the target region.

     

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