Effects of nitrogen application rate on summer maize (Zea mays L.) yield and water–nitrogen use efficiency under micro–sprinkling irrigation in the Huang–Huai–Hai Plain of China

ABSTRACT

To improve the grain yield (GY) and water–nitrogen (N) use efficiency of summer maize, a 2–year field experiment was conducted using micro–sprinkling irrigation water–fertilizer integration. Surface irrigation and N application methods were applied in the control (CK, irrigation at sowing; 300 kg N ha⁻¹). Under water–fertilizer integration, N was applied at five rates (0, 120, 180, 240, and 300 kg N ha⁻¹, N applied at sowing, jointing, and tasseling and ratio of 1:1:1; designated WN₀, WN₁₂₀, WN₁₈₀, WN₂₄₀, and WN₃₀₀, respectively). The leaf area index and dry matter accumulation increased with increasing N application rate, with a slower rate of increase when N application rate ≥180 kg N ha⁻¹. Compared with CK, the GY of WN₃₀₀, WN₂₄₀, WN₁₈₀, and WN₁₂₀ was not significantly different,but WN₁₂₀ significantly decreased by 7.16% and 5.47% than WN₂₄₀ and WN₃₀₀.The evapotranspiration,irrigation amount,and N application rate in WN₁₈₀ were 9.86%–16.40%, 47.11%–52.23%, and 40% lower,respectively,than in CK,while the water use efficiency and N partial factor productivity was 3.38%–15.14% and 32.04%–60.43% higher.Thus,application of 180 kg N ha⁻¹ with water–fertilizer integration can achieve high GY and improve resource–use efficiency.

KEYWORDS:

• Water–fertilizer integration
• micro–sprinkling irrigation
• summer maize
• grain yield
• water–nitrogen use efficiency

Acknowledgements

We thank the anonymous reviewers and editors for their constructive comments on this manuscript.

Disclosure of potential conflicts of interest

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was funded by the Major Scientific and Technological Innovation Project of Shandong Province(2019JZZY010716), the Key Research and Development Program of Shandong Province (2018GNC111007), and the Special Fund for Agro–scientific Research in the Public Interest(201503130).