Pursuing sustainable high‐yield winter wheat via preanthesis dry matter and nitrogen accumulation by optimizing nitrogen management

Abstract

Quantitative understanding of photosynthetic production of winter wheat (Triticum aestivum L.) under N fertilizer management is crucial for achieving sustainable high grain yield with less environmental risks. A 3‐yr study was conducted to evaluate dry matter and N accumulation for sustainable high grain yield with respect to preanthesis N management of winter wheat in the North China Plain. Optimal nitrogen application rate (Opt.N) was determined by subtracting soil nitrate measured at root layers from the target N‐demand for wheat. Other treatments included no N fertilizer control, conventional farmer N practice, and 70 and 130% of Opt.N. The highest grain yield (9 t ha−1) with high N use efficiency (NUE) was attained with Opt.N rate which is predominantly attributed to high dry matter (69%) and N accumulation (94%) from sowing to preanthesis. Most remarkably, N remobilization from preanthesis contributed nearly 97% of grain N accumulation. Highest dry matter production was achieved when the critical plant N concentration reached 2.90% at stem elongation stage and 1.91% at anthesis. The maximum leaf area index and photosynthetic rate needed for high dry matter production were realized with similar critical plant N concentration during preanthesis (2.55 and 2.36 for at GS31, respectively) and at GS64 (2.01 and 1.83%). Supplying additional N fertilizer over Opt.N increased neither grain yield nor grain N accumulation but heightened environmental risks from soil N surplus. These results highlight the importance of preanthesis N fertilizer optimization and provide effective N management strategy to enable high wheat yield with high NUE.

Post-anthesis Relationships Between Nitrogen Isotope Discrimination and Yield of Spring Wheat Under Different Nitrogen Levels

“…The concentration of 15 N in the ear did not decrease much with time (14 DAAmaturity) as it did in stem and leaves, except under N1 and N2 (Figure 2). Similar effects have been observed in sorghum (He et al, 2022). The ears serve as a strong N sink, impacting N accumulation in the ears throughout grain filling, whereas the shoots provide nutrients to the ears (Aranjuelo et al, 2013;Zhou et al, 2016;Sun et al, 2018).…”