Developing Functional Relationships between Soil Waterlogging and Corn Shoot and Root Growth and Development.

Charles Hunt Walne,K. Raja Reddy

doi:10.3390/plants10102095

Abstract

Short- and long-term waterlogging conditions impact crop growth and development, preventing crops from reaching their true genetic potential. Two experiments were conducted using a pot-culture facility to better understand soil waterlogging impacts on corn growth and development. Two corn hybrids were grown in 2017 and 2018 under ambient sunlight and temperature conditions. Waterlogging durations of 0, 2, 4, 6, 8, 10, 12, and 14 days were imposed at the V2 growth stage. Morphological (growth and development) and pigment estimation data were collected 15 days after treatments were imposed, 23 days after sowing. As waterlogging was imposed, soil oxygen rapidly decreased until reaching zero in about 8–10 days; upon the termination of the treatments, the oxygen levels recovered to the level of the 0 days treatment within 2 days. Whole-plant dry weight declined as the waterlogging duration increased, and after 2 days of waterlogging, a 44% and 27% decline was observed in experiments 1 and 2, respectively. Leaf area and root volume showed an exponential decay similar to the leaf and root dry weight. Leaf number and plant height were the least sensitive measured parameters and decreased linearly in both experiments. Root forks were the most sensitive parameter after 14 days of waterlogging in both experiments, declining by 83% and 80% in experiments 1 and 2, respectively. The data from this study improve our understanding of how corn plants react to increasing durations of waterlogging. In addition, the functional relationships generated from this study could enhance current corn simulation models for field applications.

Highlights

Waterlogging is a severe abiotic stress occurring when the soil profile surrounding a plant’s root system becomes oversaturated with excess water
Air temperature and soil temperature were warmer, and daily solar radiation was higher during Exp. 2
This study examined the impact of increasing durations of waterlogging from 0 to 14 days on corn’s early season growth and development

Summary

Introduction

Waterlogging is a severe abiotic stress occurring when the soil profile surrounding a plant’s root system becomes oversaturated with excess water. Waterlogging is part of the broader stress of flooding, which encompasses both situations where the soil profile is oversaturated and when visual ponding occurs above the soil surface [1]. Waterlogging can occur anytime soil moisture levels rise above the field capacity. Water inputs exceed a soil’s ability to move water off the soil surface and drain internally. Excessive moisture levels result in the aerated pore space filling with water. A water-filled pore space leads to soil oxygen levels rapidly depleting as the transfer of oxygen and other gasses is blocked between the soil and the atmosphere. Oxygen diffuses 10,000 times more slowly in water than in air [2,3]

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