Abstract:

In field experiment, ‘Liangyu 188’ was used as material, four nitrogen treatments and three phosphorus treatments were set, and a total of 12 combinations were obtained. Photosynthetic characteristics of maize leaves at jointing stage and filling stage were determined and the agronomic and yield characters in the ripening period were measured, to maximize fertilizer efficiency by exploring the optimal ratio of nitrogen and phosphorus. The results showed that under the condition of N₃₀₀P₂₄₀, the stomatal conductance of ‘Liangyu 188’ increased by 10.75%, the net photosynthetic rate decreased by 61.5%, the transpiration rate increased by 64.24%, water use efficiency decreased by 85.66%. It can be found that under the combined treatment of nitrogen and phosphorus, the number of grains per panicle and the weight of 100-grain increased with the increase of fertilizer application. When the nitrogen application amount was 300 kg/hm ² and the phosphorus application amount was 240 kg/hm ², the plant height of maize was 233 cm, the ear height was 82.33 cm, the kernel number was 582.67, and the 100-grain weight was 41.65 g, the grain yield reached the maximum of 9076.05 kg/hm ². The results showed that when the nitrogen application rate was 300 kg/hm ² and the phosphorus application rate was 240 kg/hm ², the maize variety ‘Liangyu 188’ had the best photosynthetic efficiency, better agronomic traits such as plant height, ear height and grain number per ear, and the yield increase effect was the best.

Key words: Maize, Combined Application of Nitrogen and Phosphorus, Photosynthetic Characteristics, Agronomic Traits, Yield