How Does the Waterlogging Regime Affect Crop Yield? A Global Meta-Analysis.

Li-Xin Tian,Jing Li,Feng Yan,Fei-Fei Zhang,Yang Dong,Yu-Chuan Zhang,Bai-Li Feng,Peng-Liang Chen

doi:10.3389/fpls.2021.634898

Abstract

Waterlogging, an abiotic stress, severely restricts crop yield in various parts of the world. Thus, we conducted a meta-analysis of 2,419 comparisons from 115 studies to comprehensively evaluate the overall change in crop yield induced by waterlogging in the global region. The results suggested that waterlogging obviously decreased crop yield by 32.9% on average, compared with no waterlogging, which was a result of a reduced 1,000-grain weight (13.67%), biomass (28.89%), plant height (10.68%), net photosynthetic rate (Pn, 39.04%), and leaf area index (LAI, 22.89%). The overall effect of a waterlogging regime on crop yield is related to the crop type; the crop yield reduction varied between wheat (25.53%) and cotton (59.95%), with an overall average value of 36.81% under field conditions. In addition, we also found that compared with no waterlogging, waterlogging in the reproductive growth stage (41.90%) caused a greater yield reduction than in the vegetative growth stage (34.75%). Furthermore, decreases in crop yield were observed with an extension in the waterlogging duration; the greatest decreases in crop yield occurred at 15 < D ≤ 28 (53.19 and 55.96%) under field and potted conditions, respectively. Overall, the results of this meta-analysis showed that waterlogging can decrease crop yield and was mainly affected by crop type, growth stage, and experimental duration.

Highlights

Waterlogging is an identifiable phenomenon where free water overlays the soil surface of cropland (Striker, 2012)
The greatest decrease in cotton yield of 59.95% was observed under waterlogging in comparison to treatments without waterlogging, and wheat had the smallest decrease in grain yield of 25.32% in a field experiment (P < 0.05; Figure 3A)
The results indicated that crop yield decreased by an average of 32.9% under waterlogging compared to no waterlogging

Summary

Introduction

Waterlogging is an identifiable phenomenon where free water overlays the soil surface of cropland (Striker, 2012). The oxygen in waterlogged soil is rapidly exhausted, resulting in the roots changing from aerobic respiration to anaerobic fermentation, while CO2 and ethylene concentrations accumulate. This causes a severe decrease in the ATP synthesis of root cells and impacts multiple metabolic processes of plants (Sairam et al, 2009; Pampana et al, 2016; Kaur et al, 2020). The consequence of damaged root function under waterlogging is stomatal closure, which restricts water and nutrient uptake; this will hinder the influx of carbon dioxide into the leaf as well as transpiration, causing leaf wilting and senescence, in addition to the inhibition of photosynthesis, leading to lower biomass accumulation, thereby reducing kernel weight and grain yield (Ashraf, 2012; Shao et al, 2013; Voesenek et al, 2013; Arguello et al, 2016)

Methods

Results

Conclusion