Controlled‐release nitrogen fertilizer management influences grain yield in winter wheat by regulating flag leaf senescence post‐anthesis and grain filling

Abstract

Controlled‐release nitrogen fertilizer (CRNF) is expected to meet the nutrient demands for crop growth with single fertilizer application, so as to achieve high‐yield, high‐efficiency, and labor‐saving cultivation. However, under current CRNF practices, a single application of CRNF in winter wheat (Triticum aestivum L.) usually fails to achieve satisfactory effects due to insufficient nitrogen (N) supply in the later growth stage, contributing to premature leaf senescence and poor grain filling. To determine a reasonable CRNF application strategy for improving the grain weight and yield of winter wheat, the responses of leaf senescence, photosynthetic capacity, grain‐filling characteristics, and grain yield to different CRNF types [polymer‐coated urea (PCU), sulfur‐coated urea (SCU), and urea‐formaldehyde (UF)] and fertilization practices [single fertilization (P1) and twice‐split fertilization (P2)] were investigated. The results showed that, compared with P1, P2 increased the activities of catalase, peroxidase, and superoxide dismutase, alleviated the accumulation of malondialdehyde, delayed flag leaf senescence, and enhanced the net photosynthetic rate (Pn) of the flag leaves, which promoted assimilate accumulation and transport to the grains. These advantages in P2 improved the grain‐filling process of wheat, with the active filling duration (T), average filling rate (G), and maximum filling rate (Gmax) in P2 all being higher than those in P1, which significantly increased the 1000‐grain weight (TGW) and grain yield of wheat. Among the three CRNFs, PCU showed advantages in Pn at the milk‐ripe stage (Zadoks growth stage, GS75), dry matter accumulation post‐anthesis, T, Gmax, and G, which contributed to TGW and grain yield. Overall, our study suggested that the twice‐split application of CRNF could substantially delay leaf senescence post‐anthesis and increase photosynthetic capacity, thus improving grain filling and productivity in winter wheat.

The Impact of a Six-Hour Light–Dark Cycle on Wheat Ear Emergence, Grain Yield, and Flour Quality in Future Plant-Growing Systems

“…This increased competition is further confirmed by the faster leaf senescence in the HL plants compared to the LL plants following the decrease in EC to 1000 µS cm −1 . Since flag-leaf photosynthesis plays an important role in grain filling [ 37 ], faster flag-leaf senescence eventually results in less assimilate availability during grain filling [ 38 , 39 , 40 ].…”

Split application of polymer-coated urea combined with common urea improved nitrogen efficiency without sacrificing wheat yield and benefits while saving 20% nitrogen input

“…To evaluate the economic benefits of different treatments, the wheat output and net benefit were calculated by the following formula ( Equations 4 , 5 ) ( Ma et al., 2022 ):…”

“…Due to the limited of nutrient release cycle, N release from one-time application of CRNF is difficult to cover the entire wheat growth period. As a result, although one-time application of CRNF can satisfy N supply for tiller differentiation at the seedling stage, it easily leads to N deficiency in the later stage of wheat, which limits the matter accumulation and grain filling post-anthesis (Ma et al, 2022). The study on wheat grown in paddy soil by Ji et al ( 2012) also confirmed that one-time application of CRNF reduced the volatilization of NH 3 and the emissions of N 2 O in wheat fields compared to common urea, but did not significantly improve the wheat yield and NUE.…”

Ekmeklik buğdayda (Triticum aestivum L.) 15N izotopu kullanılarak çiçeklenme sonrası kuraklığın azot mobilizasyonu ve gelişimine etkileri

“…Flag leaves contribute the majority of assimilates for grains during post-anthesis stages and increased N supply results in increased leaf area, leaf nitrogen and chlorophyll content in wheat flag leaves (Tamang et al 2017). Flag leaf senescence and photosynthesis performance are highly regulated by N supply which plays a vital role in the grain-filling process and alters dry matter accumulation (Ma et al 2022). Although flag leaf δ 15 N results showed that flag leaf nitrogen increased to comparably extents under drought conditions.…”