水稻冠层叶片SPAD数值变化特征及氮素营养诊断

Characteristics and diagnosis of nitrogen nutrition for rice canopy leaf SPAD value changes

建立水稻Oryza sativa氮营养诊断模型,实时反映水稻植株氮素营养状况,对水稻田间管理至关重要。于2015年在浙江省德清市开展田间试验,选择‘甬优538’‘Yongyou 538’和‘秀水134’‘Xiushui 134’作为代表品种,设置5个施氮水平0(N0),70.0(N1),140.0(N2),210.0(N3),280.0(N4)kg·hm-2,通过研究不同施氮水平下2个水稻品种冠层叶片作物分析仪器开发值(SPAD)变化规律,探究5个不同施氮水平下植株氮质量分数的变化趋势,并利用归一化SPAD指数(INDSPAD14)估算植株氮质量分数。结果表明:顶4叶相较其他叶片更能指示水稻植株氮质量分数,归一化SPAD指数与N0~N4所有不同施氮量组别之间冠层叶片氮质量分数呈显著正相关(P<0.05),‘甬优358’水稻品种决定系数为0.69~0.96,‘秀水134’品种决定系数为0.64~0.94。该指数可以对水稻冠层叶片氮质量分数快速估测。

Nitrogen(N)is important for rice growth.To establish a rice(Oryza sativa)nitrogen nutrition diagnostic model that could reflect the N status of a rice organism and that could be convenient for rice field management,a rice community test was conducted in Deqing City,Zhejiang Province in 2015.Oryza sativa‘Yongyou 538’and‘Xiushui 134’were taken as the representative cultivars.Five levels of N were established:0(N0)(ck),70.0(N1),140.0(N2),210.0(N3),and 280.0(N4)kg·hm-2.Measurement of rice SPAD(soil and plant analyzer development)values were made using a portable SPAD-502 meter and followed by a correlation analysis.Results showed that the fourth leaf from the top was a good indication of plant nutrition status.There was a significant positive correlation between the normalized SPAD index(INDSPAD14)and N content in canopy leaves with the N0-N4 treatments.The coefficients of determination for‘Yongyou 358’r2=0.69-0.96 and for‘Xiushui 134’r2=0.64-0.94.By analyzing the relationship between INDSPAD14 and plant N content,a diagnostic model of rice N concentration was established.