利用SPAD氮饱和指数指导玉米中后期氮素诊断

研究多年份不同玉米品种各施肥处理SPAD氮素饱和指数变化规律,为寒地玉米氮素诊断提供理论数据。通过研究品种和处理两因素SPAD氮素饱和指数,利用SPAD氮素饱和指数指导玉米中后期氮素诊断,以2018～2020年最佳施肥处理SPAD氮素饱和指数为基础,建立平均年份SPAD氮素饱和指数模型,分别与2018、2019、2020年SPAD氮素饱和指数进行相关性分析。结果表明,最佳施肥产量处理为纯氮160 kg/hm²。通过多项式回归方程、指数回归方程、乘幂回归方程、线性回归方程和对数回归方程的计算,得出多项式回归方程相关性最高。对于玉米氮素诊断有较好指导作用,为寒地玉米中后期氮素诊断提供理论数据。

SPAD Nitrogen Saturation Index Was Used to Guide Nitrogen Diagnosis in Middle and Late Stage of Maize

In order to provide theoretical data for the diagnosis of maize nitrogen in the cold region, the change rule of SPAD nitrogen saturation index under different fertilization treatments of different maize varieties over many years was studied. Through research the two factors SPAD nitrogen saturation index, using SPAD nitrogen saturation index guiding maize middle nitrogen diagnosis, based on the SPAD nitrogen saturation index of the optimal fertilization treatment in 2018-2020, the SPAD nitrogen saturation index model of the average year was established, and the correlation analysis was conducted with the SPAD nitrogen saturation index in 2018, 2019 and 2020, respectively. The results showed that the optimal fertilization yield treatment was pure nitrogen 160kg/ha. By calculating the polynomial regression equation, exponential regression equation, power regression equation, linear regression equation and logarithmic regression equation, the polynomial regression equation had the highest correlation. It has a better guiding role for maize nitrogen diagnosis in the next year and provides theoretical data for maize nitrogen diagnosis in the middle and late period in the cold region.