Remedial Application of Urea Eliminates Yield Losses in Wheat Waterlogged during Stem Elongation

Jinfeng Ding,Desheng Guo,Wenshan Guo,Dejun Liu,Mingxiao Yin,Xinkai Zhu,Chunyan Li,Peng Liang,Min Zhu

doi:10.3390/agriculture10010023

Abstract

Waterlogging remains a critical constraint to wheat production in areas with high rainfall. Exogenous application of nitrogen (N) can effectively diminish the adverse effects of waterlogging, but varies with specific events. To provide highly efficient remedial strategies, this pot study investigated the effects of urea application following 10 days of waterlogging initialing at the stem elongation stage (Zadoks growth stage, GS33). The remedial measures included foliar spray of urea solution at a single dose (0.108 g urea per pot) at the 0th day after finishing waterlogging (FU1) and twice at the 0th and 7th day (FU2), and soil surface spray of urea solution at single and double doses when soil water content was approximately 80% of field capacity (SU1 and SU2, respectively). Waterlogging significantly reduced grain yield, total N uptake, and N partial factor productivity (by 11%, 18%, and 11%, respectively), but subsequent remedial measures improved these to variable degrees. Reduction in grain yield owing to waterlogging could be effectively alleviated and even eliminated using these remediations. Grain yield and N partial factor productivity were higher under FU2 and SU2 than FU1 and SU1. Among all treatments, plants under SU2 exhibited the highest total N uptake and top-dressing N recovery. Diminished yield losses were attributed to (1) increased kernel number per spike resulting from increased spikelet fertility and kernel number per spikelet and (2) increased photosynthetic production by delaying senescence (improved chlorophyll content and maintained green leaf area) of the top leaves. This study suggests that urea application for a brief period of time following waterlogging during the stem elongation stage has remarkable remedial effects.

Highlights

Waterlogging is one of the global abiotic stresses that affect crop yield and quality [1,2]
Compared with waterlogging treatment (WA), the remedial measures (FU1, FU2, SU1, and SU2) increased grain yield by 6–17%, but significant differences were only found between FU2 and WA and SU2 and WA
Grain yields with these remedial treatments were similar or even slightly higher than that with drainage treatment (DR)

Summary

Introduction

Waterlogging is one of the global abiotic stresses that affect crop yield and quality [1,2]. Soil waterlogging frequently occurs on 12% of arable land, causing about 20% of reported yield losses [7]. Waterlogging affects 10–15 million ha of wheat annually, resulting in 20–50% yield losses [8]. With global climate change, waterlogging events have become more frequent, severe, and unpredictable [9]. The influences of waterlogging on wheat vary with soil property, meteorological condition, cultivar, growth stage, and exposure duration [10,11,12,13]. Waterlogging at the early growth stages reduces tiller number and inhibits spike development [14,15,16].

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Results

Discussion

Conclusion