叶绿素仪和硝酸盐反射仪对大白菜氮素营养诊断的比较研究

Comparison of Chlorophyll Meter and Nitrate Reflectrometer of Nitrogen Nutrition Diagnosis of Chinese Cabbage

摘要:

本文在6个氮肥处理下,利用叶绿素仪和硝酸盐反射仪对大白菜的氮素营养诊断进行研究,筛选出适合的诊断方法,并根据诊断指标建立大白菜的氮肥推荐施肥模型。结果表明,大白菜莲座期和结球期的叶片SPAD值和叶柄硝酸盐浓度与施氮量、植株全氮含量均有较好的相关性,SPAD值和叶柄硝酸盐浓度都能反映大白菜氮素营养状况,但相关系数SPAD值高于叶柄硝酸盐浓度,叶绿素仪法更适合大白菜氮素营养快速诊断。在大白菜莲座期和结球期,叶片SPAD临界值分别为38.57、40.36,基于叶片SPAD值的氮肥推荐模型能够进行大白菜各生育时期的推荐氮肥施用。

Abstract:

Under six nitrogen fertilizer treatments, nitrogen nutrition diagnosis of Chinese cabbage was studied by chlorophyll meter and nitrate reflectometer. The aim of the study was to build Chinese cabbage nitrogen fertilization recommendation model by using the most suitable diagnosis approach. The results indicated that SPAD value of leaves and nitrate concentration of petioles at rosette and heading stage of Chinese cabbage were well correlated with nitrogen application rate and total nitrogen content of plants. SPAD value of leaves and nitrate concentration of petioles can reflect nitrogen nutrition status of Chinese cabbage, however the correlation coefficient of SPAD value of leaves was better than nitrate concentration of petioles. Chlorophyll meter is more suitable for rapid diagnosis of nitrogen nutrition of Chinese cabbage. The critical SPAD values of leaves were 38.57 and 40.36, respectively in two growth stages of Chinese cabbage. Nitrogen recommendation model based on SPAD value of leaves can be used to recommend nitrogen fertilizer application in different growth stages of Chinese cabbage.