Plastic response of leaf traits to N deficiency in field-grown maize

Abstract

Nitrogen (N) utilization for crop production under N deficiency conditions is subject to a trade-off between maintaining specific leaf N content (SLN) important for radiation-use efficiency (RUE) versus maintaining leaf area (LA) development, important for light capture. This paper aims to explore how maize deals with this trade-off through responses in SLN, LA, and their underlying traits during the vegetative and reproductive growth stages. In a ten-year N fertilization trial in Jilin province, Northeast China, three N fertilizer levels have been maintained: N-deficiency (N0), low N supply (N1), and high N supply (N2). We analyzed data from years 8 and 10 of this experiment for two common hybrids. Under N deficiency, maize plants maintained LA and decreased SLN during vegetative stages, while both LA and SLN decreased comparably during reproductive stages. Canopy SLA (specific leaf area, cm 2/g) decreased sharply during vegetative stages and slightly during reproductive stages, mainly because senesced leaves in the lower canopy had a higher SLA. In the vegetative stage, maize maintained leaf area at low N by maintaining leaf biomass (albeit hence having N content/mass) and slightly increasing SLA. These responses to N deficiency were stronger in maize hybrid XY335 than in ZD958. We conclude that the main strategy of maize to cope with low N is to maintain leaf area, mainly by increasing SLA throughout the plant but only during the vegetative growth phase.

Coupling Effects of Optimized Planting Density and Variety Selection in Improving the Yield, Nutrient Accumulation, and Remobilization of Sweet Maize in Southeast China

“…Nitrogen (N), phosphorus (P), and potassium (K) are the three essential nutrients for maize growth and development, playing an important role in maize yield formation [24][25][26]. The yield of maize is significantly positively correlated with the accumulation and remobilization of N, P, and K nutrients.…”