Using maize hybrids and in-season nitrogen management to improve grain yield and grain nitrogen concentrations

摘要

Understanding the dynamics of biomass and nitrogen (N) accumulation in maize cultivars and the relationship of these parameters to N management is essential to improve our ability to increase maize grain yield and grain N concentration (GNC). We conducted a field experiment in 2010 and 2011, using five rates of N application and three maize hybrids (YD13, ZD958, and XY335) in Quzhou County, the North China Plain, to evaluate grain yield and GNC under different N managements and with different hybrids. The maximum grain yield in 2010-2011 averaged 8.85 and 8.90 Mg ha(-1) for ZD958 and XY335, respectively, which was approximately 45% higher than the yield of YD13 (6.10 Mg ha(-1)). GNC in XY335 was highest among the three hybrids. The maximum GNC for 2010-2011 averaged 1.62% for XY335, 1.42% for ZD958, and 1.48% for YD13. Compared to YD13, XY335 and ZD958 had higher biomass and N accumulation during the grain-filling period and at harvest, and the apparent amount of N remobilization from stover (leaf plus stem) after silking was greater in XY335 than in ZD958, which contributed to high yield and GNC in XY335. The optimal N application rate (ONR) based on in-season N management was 149 kg ha(-1), and split at the 3-leaf (V3), 6-leaf (V6), and 10-leaf (V10) stages. All maize hybrids achieved their maximum grain yield and >95% of their maximum GNC with ONR treatment. Selection of appropriate hybrids such as XY335 in combination with optimal N management can increase grain yield and GNC obtained on the North China Plain