Effects of three N strategies on tillering and yield of low shoot density winter wheat

Abstract

Application of nitrogen (N) in early spring is often recommended for low shoot density winter wheat in northern temperate areas such as Sweden. Regional N-strategy field trials in such areas generally show no relationship between early N and grain yield but the effects on shoot numbers and other yield components are seldom investigated. This study quantified the effect of three N fertilization strategies on the number of tillers at GS30-31 and the grain yield of winter wheat with low shoot density in early spring, in order to evaluate the importance of early N application. The investigations were carried out from 1999Á2002 in four annual field experiments on a clay soil in south-west Sweden using winter wheat (cvs. Kosack and Tarso) with shoot densities in early spring ranging from 360Á850 shoots m (2 . A positive relationship between time of first N application as number of days before GS30 and increase in number of shoots from GS20-21 to GS30-31 was observed. The relationship was strongest in experiments with the lowest shoot density in early spring (360Á560 shoots m (2 ) and the additional increase with each day of earlier availability of N before GS30 was 11 shoots m (2 . In wheat with this low shoot density in early spring, N was needed before GS30 to avoid yield reductions. Whether N was applied and available 24 or 13 days before GS30 did not affect yield, despite significantly more shoots being present at GS30-31 with earlier N application.

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

“…These critical plant N concentrations are similar to those reported in previous studies of moderate‐yielding winter wheat systems (5–7 t ha −1 ) on the NCP (Yue et al., 2012; Zhao et al., 2014). In contrast, the critical plant N concentration at GS31 is lower than that for high‐yielding winter wheat system in Europe (Engström & Bergkvist, 2009). It could be, at least in part, due to the biomass dilution effect resulting from more tiller production.…”

Tiller development affected by nitrogen fertilization in a high‐yielding wheat production system

“…In Europe, in contrast, the critical N concentrations in high-yielding winter wheat were 3.24% at GS 31 and 1.70% at GS 64 (Justes, Mary, Meynard, Machet, & Thelier-Huche, 1994). It is likely the higher concentration values at GS 31 in Europe was due to the lower plant aboveground biomass associated with the low number of stems (Engstrom & Bergkvist, 2009;Greenwood, Neeteson, & Draycott, 1986). Similarly, the lower N concentration at GS 64 in Europe than on the NCP was likely Crop Science F I G U R E 2 Across three growing seasons (2015, 2016, and 2017), the relationship between biomass per stem and the N concentration of aboveground stems at (a-c) the beginning of the spring growth stage (Zadoks Growth Stage [GS] 25), (d-f) the stem elongation stage (GS 31), and (g-i) the anthesis stage (GS 64).…”

“…Proper fertilizer N application is an effective way to regulate population establishment of wheat, as it can exert a significant effect on tillering (Engstrom & Bergkvist, 2009;Weisz, Crozier, & Heiniger, 2001;Ye et al, 2011). Increases in N application rate can increase root-zone soil mineral N (N min ) and further increase the N concentration in wheat plants (Yue et al, 2012), which can in turn promote tiller production and increase the number of stems (Engstrom & Bergkvist, 2009). Overuse of N fertilizer to achieve high yield by increasing the number of spikes is a common practice in China, especially on the North China Plain (NCP), which accounts for >80% of national wheat production (NBSC, 2018).…”

Estimation of Winter Wheat Tiller Number Based on Optimization of Gradient Vegetation Characteristics

“…Tillering can have positive or negative effects on wheat yield, but reasonable tillering is positively associated with wheat yield [5]. Tillering of wheat is affected by external factors, and the proper application of nitrogen (N) fertilizer can significantly affect tillering and promote tillering yield [6]. The number of tillers also increases with an increase in planting density [7].…”