Effects of different nitrogen application methods on enzyme activities in leaves at late growth stage of spring maize.

[Objective] This paper aimed at exploring the effects of different nitrogen application methods on the enzyme activities of leaves at ear position in late growth stage of maize. [Method] By pot experiment, the superoxide dismutase (SOD) activity, peroxidase (POD) activity, malonyl dialdehyde (MDA) content and soluble protein content were determined. [Result] At the filling stage and ripening stage, with the increasing of nitrogen application rate, MDA content gradually decreased, while SOD activity, POD activity and soluble protein content increased. MDA content with two topdressing nitrogen was lower than that with one top dressing nitrogen at the same nitrogen application rate, while SOD activity, POD activity and soluble protein content with two topdressing nitrogen were higher than that with one topdressing nitrogen. [Conclusion] Different nitrogen application methods have relatively significant effects on the MDA content, SOD activity, POD activity and soluble protein content, which is of certain directive significance for preventing spring maize prematuration.