Effects of different fertilizer combinations on the yield and nitrogen use efficiency of summer maize in Jiangsu Province, China

Abstract

The rational application of nitrogen (N) fertilizer plays a crucial role in promoting crop growth and increasing yields. The application of slow-release fertilizer has emerged as an important agronomic measure to further increase yield and production efficiency. In this study, a field trial with the maize hybrid Jiangyu877 was conducted to investigate the effects of six fertilizer combinations [no fertilizer (P1), common N application (P2), slow-release N application (P3), common N and slow-release N 1:1 application (P4), 1:2 application (P5), and 2:1 application (P6)] on yield and nitrogen use efficiency (NUE). Fertilization significantly increased maize yield, with the greatest increase occurring in the treatment combining common and slow-release N. Among all the treatments receiving equal N amounts, the P5 resulted in the highest yield and NUE than the other treatments did. Compared with those in the P3, the dry matter accumulation of the P5 increased by 6.6-13.7%, the N accumulation increased by 13.0-16.3%, and the NUE increased by 8.1-11.5%. In addition, compared with those in the P3, the 1000-grain weight and number of grains per cob significantly increased, the yield increased by 2.6-4.5%, and the net income increased by 17.1-80.4% over the 3 years. In conclusion, in the summer maize production in Jiangsu Province, China, under a planting density of 75,000 plants ha^-1, the recommended fertilization method involves a one-time base application of common N and slow-release N (1:2, common N at 75 kg ha^-1: slow-release N 150 kg ha^-1) to realize synergistic improvements in yield and efficiency.

Keywords: Maize; Net return; Nitrogen fertilization; Nitrogen use efficiency; Slow-release fertilizer.

Fig. 1

Nitrogen (N) release curves for slow-release nitrogen fertilizer in 25°C hydrostatic water.

Fig. 2

Effects of different fertilizer combinations on maize dry matter accumulation. The bars represent the means (n = 3). Different letters represent significant differences among different treatments at the same location. (Tukey’s HSD post hoc tests, P < 0.05). P1, no N; P2, common N; P3, slow-release N; P4, common N and slow-release N 1:1; P5, common N and slow-release N 1:2; P6, common N and slow-release N 2:1.

Fig. 3

Effects of different fertilizer combinations on nitrogen uptake. The bars represent the mean (n = 3). Different letters denote significant treatment differences (Tukey’s HSD post hoc tests, P < 0.05).P1, no N; P2, common N; P3, slow-release N; P4, common N and slow-release N 1:1; P5, common N and slow-release N 1:2; P6, common N and slow-release N 2:1.

Fig. 4

Correlation analysis of the effects of different fertilizer combinations on yield. * and ** indicate correlations significant at P<0.05 and P<0.01 level, respectively. .