水稻氮素及钾素叶位分布特点及诊断叶位研究

Distribution of nitrogen and potassium in different leaf positions and relationship with nitrogen and potassium diagnosis in rice (Oryza sativa)

利用盆栽试验研究水稻拔节期、孕穗期不同叶位氮素及钾素时空分布特征,并进行了不同叶位含氮、钾量与总叶片含氮、钾量以及施氮、钾量的线性相关分析。结果表明,拔节期叶位间含氮量由上而下逐级增加,孕穗期叶位间含氮量由上而下逐级递减,两个时期内叶位间含钾量均表现为由上而下逐级递减。增施氮能减少叶位间氮素的差异,但增施钾叶位间含钾量的差异无显著变化。相关分析表明,拔节期水稻顶1叶适合作为氮营养的诊断叶片,孕穗期水稻顶3叶或顶4叶适合作为氮营养的诊断叶片,顶1叶适合作为拔节期、孕穗期钾营养的诊断叶片。

Pot experiments with rice were conducted to investigate the nitrogen （N） and potassium （K） distributions in different leaf positions and growth stages. Linear correlation analysis between N, K contents in different leaves, total N, K content in leaves and the amount of N, K application were also studied. The results showed that N content increased from upper leaf position to lower position in jointing stage, while the reverse was Obvious in booting stage. K content decreased from upper leaf position to lower position in both jointing and booting stages. The differences of N content among leaf positions were mitigated following the increasing amount of N application. However, no significant change was observed in K content among different leaf positions when the amount of N application was increased. According to the correlation analysis, the first position of rice leaf was suitable for N diagnosis in jointing stage, and the third or the fourth position of rice leaf was suitable for N diagnosis in booting stage. The first position of rice leaf was suitable for K diagnosis in both jointing and booting stages.