不同地力和施氮水平下水稻叶片SPAD值及产量的分析

以Q优6号为材料,分析了不同地力条件下不同施氮水平对水稻叶片SPAD值和产量的影响。结果表明,水稻产量与表观供氮量存在极显著的曲线相关,且当表观供氮量在575.27 kg/hm~2时,Q优6号产量较高;不同处理下各生育时期SPAD值大小顺序为抽穗期拔节期成熟期,且差异主要表现在抽穗期和成熟期;拔节期和抽穗期不同地力和施氮水平下水稻冠层4张叶片各自的差异主要表现在顶3叶和顶4叶上,可以利用两者的SPAD值作为参数进行氮素营养诊断;SPAD值与表观供氮量之间存在显著线性相关,且采用SPAD_(L3×L4/mean)进行拟合时效果更好,均达到极显著水平。获取水稻叶片SPAD值次级指标可以实现对田块速效氮含量的估计。

Analysis of SPAD Value of Rice Leaf and Yield Under Different Soil Fertility and Nitrogen Application

SPAD value of rice canopy leaves and yield under different soil fertility and nitrogen application were analyzed, Qyou 6 as material. The results showed that the curve relationship between yield and apparent nitrogen supply was very significant, and there was a higher yield for Qyou 6 when apparent nitrogen supply was 575.27 kg/hm 2. The SPAD value of every growth stage under different soil fertility and nitrogen application was heading stage>jointing stage>maturity stage, and the difference of SPAD value were mainly at head-ing stage and maturity stage. The differences of SPAD value of four rice canopy leaves of different soil fertility and nitrogen application were mainly in third leaf and fourth leaf. Their SPAD values could be used as parameter to diagnose the nutritional status of nitrogen. The linear relationship between SPAD value and apparent nitrogen supply was significant, and the matching effect of adopting SPAD L3×L4/mean was best. The secondary index of SPAD value obtained from rice canopy leaves could estimate available nitrogen of soil.