Improving Integration of Micro-spraying Irrigation and Nitrogen Fertilization to Increase the Lodging Resistance of Summer Maize

Abstract

【Objective】 Micro-spraying hose irrigation is easy to manage and has been increasingly used in arable crops. The purpose of this paper is to study experimentally the impact of its integration with nitrogen fertilization on lodging resistance of summer maize in Huang-Huai-Hai Plain, China. 【Method】 The experiment was conducted in a field and compared two irrigation schedules: irrigating at the beginning of sowing, jointing, beg bell and heading stage, respectively (W1); and irrigating at sowing and big bell stage only (W2). Associated with each irrigation were two nitrogen applications: 210 kg/hm2 (N1) and 150 kg/hm2 (N2). For each treatment, we measured the crop traits, mechanical and lodging resistance index of the third internode, in-situ lodging resistance, inclination angle at different growth stages, as well as the grain yield. 【Result】 N1 was optimal in reducing plant height at heading and dough stage, as well as the center of the gravity height at heading and filling stage; it also improved the bending strength, puncture strength and radial compressive strength at the filling stage, as well as the lodging resistance index and critical loading resistance at the filling and dough stages, all at significant level. Compared to W2+N2, W1+N1 increased the lodging resistance at heading, filling and dough stage by 68.56%, 15.01% and 28.23%, respectively, and the associated critical loading resistance by 44.03%, 48.40% and 30.49%, respectively. Overall, W1+N1 was most effective to improve lodging resistance, including lodging resistance index and critical lodging resistance, as well as the grain yield. W2+N2 was the worst. In terms of loading resistance index, critical loading resistance and grain yield, W1+N1 and W2+N1 were more effective than W1+N2 and W2+N2. 【Conclusion】 Optimal scheduling irrigation and nitrogen fertilization in the micro-spray irrigation system can improve the lodging resistance and grain yield of summer maize in northern China. Our experimental results showed that increasing irrigation frequency and N fertilizer application can achieve this goal.

Keywords

• summer maize
• micro-spraying irrigation
• water and nitrogen management
• stem lodging resistance