基于SPAD值的大白菜氮素营养诊断和推荐施肥模型研究

以大白菜卵圆型品种"锦抗1号"和直筒型品种"乡情80"为试材,在6个氮肥水平下,研究了叶片SPAD值与氮素营养诊断指标、施氮量的关系以及施氮量对产量的影响。结果表明:在大白菜莲座期和结球期,2个品种的叶片SPAD值与氮素营养诊断指标及施氮量有很好的相关性;2个生育期"锦抗1号"的临界SPAD值分别为40.45、42.45,"乡情80"的临界SPAD值分别为38.57、40.36;建立了基于叶片SPAD值的大白菜氮肥推荐施肥模型。综上所述,大白菜叶片SPAD值可以作为氮素营养诊断指标,并能推荐氮肥的施用。

Nitrogen Nutrition Diagnosis and Recommended Model of N Fertilizer for Chinese Cabbage Based on SPAD Value

Different ecotype Chinese cabbage varieties of ‘Jinkang No.1’ and ‘Xiangqing 80’ were used as experimental materials.Under six nitrogen treatments,relationships between SPAD value of leaves and nitrogen nutrition diagnostic index,nitrogen application rate and the effect of nitrogen application rate on yield were studied.The results showed that there were significant correlations between SPAD value of leaves and diagnostic index of nitrogen nutrition,nitrogen application rate in rosette and heading stage of two Chinese cabbage varieties.The critical SPAD values of ‘Jinkang No.1’ were 40.45 and 42.45 respectively,and those of ‘Xiangqing 80’ were 38.57 and 40.36 respectively in two growth stages;nitrogen fertilization recommendation models for two Chinese cabbage varieties were established based on SPAD value of leaves.In conclusion,the SPAD value of Chinese cabbage leaves can be used as a diagnostic index for nitrogen nutrition to recommend the application of nitrogen fertilizer.