Abstract: To clarify the effects of nitrogen application on the growth, yield, and grain quality of spring maize under drought conditions, an experiment was conducted under moderate drought stress (relative moisture 45%±5%) and four nitrogen addition levels of 0, 120, 240 and 270 kg·hm^-2 at the two key developmental stages (jointing and tasseling) of spring maize (cultivar Danyu 405). We analyzed the responses of spring maize growth, yield component and grain quality to the interaction of drought and nitrogen application. The results showed that compared with the control treatment of suitable water and no nitrogen application, nitrogen application under drought during the jointing stage increased plant height, ear length, bald tip ratio, amino acids content, and crude protein content of spring maize, while decreased leaf area index, biomass, ear diameter, 100-kernel weight, theoretical yield, grain water content, fat content, and starch content of spring maize. The effects of nitrogen application under drought during the tasseling stage were similar to that during the jointing stage, but with negative impact on ear length. Compared with the nitrogen application under drought during the jointing stage, leaf area index, bald tip ratio, grain water content, fat, starch, amino acids, and crude protein content were increased by 18.5%, 116.7%, 4.9%, 8.6%, 1.4%, 8.8%, and 28.0% during the tasseling stage, respectively, while plant height, biomass, ear length, ear diameter, 100-kernel weight, and theoretical yield were decreased by 2.9%, 2.4%, 20.1%, 7.7%, 4.3%, and 40.8%, respectively. With increasing nitrogen application levels under drought, plant height, biomass, ear length, bald tip ratio, grain water content, and starch content increased, while leaf area index, ear diameter, 100-kernel weight, theoretical yield, fat, amino acids, and crude protein content decreased. The yield components of spring maize were negatively correlated with grain quality. Nitrogen application had an inhibitory effect on maize yield under drought, but improved grain quality to a certain extent. Our results provide scientific basis for the production management and stress control of spring maize in Liaoning Province.

Key words: drought, nitrogen application, growth, yield component, grain quality