Effects of Light Intensity and Nitrogen Level on the Growth, Photosynthetic Physiology and Dry Matter Accumulation of Maize

PurposeAs for light and nitrogen, the characteristics of growth and photosynthetic physiology of maize (Zea may L.) were studied, in order to provide scientific basis for alleviating low-light stress through rational fertilization.

MethodsPot experiments were conducted to study the effects of different light intensities and nitrogen levels on the growth, photosynthetic physiology and dry matter accumulation of maize.

ResultPlant height of maize under shading treatment was lower than those of natural light treatment in low and middle nitrogen levels. The areas of upper leaf, ear leaf and lower leaf at the filling stage in different nitrogen levels were decreased by 13.0%-35.9%, 6.1%-28.5% and 9.7%-26.4%, respectively, compared with the natural light treatment; the chlorophyll contents of the functional leaves at the early growth stage and net photosynthetic rate at the whole growth stage were decreased to different degrees. Soluble sugar contents in leaves at the jointing stage were decreased significantly by 11.1%-46.5%, and total biomass under shading treatment was decreased by 33.1%-49.7% in middle and high nitrogen levels. The leaf areas of different parts, net photosynthetic rate and root length of low nitrogen treatment were higher than those of high nitrogen treatment, and soluble sugar content in leaves and total biomass under shading treatment were also increased by 19.4%-108.3% and 51.1%-85.6% respectively, compared with medium and high nitrogen treatments.

ConclusionUnder shading condition, the growth and development of maize were restrained, and low nitrogen treatment was beneficial to dry matter accumulation compared with middle and high nitrogen treatments.