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Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
Volume 14, issue 16
Biogeosciences, 14, 3851–3858, 2017
https://doi.org/10.5194/bg-14-3851-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.

Special issue: Ecosystem processes and functioning across current and future...

Biogeosciences, 14, 3851–3858, 2017
https://doi.org/10.5194/bg-14-3851-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 29 Aug 2017

Research article | 29 Aug 2017

Morphological plasticity of root growth under mild water stress increases water use efficiency without reducing yield in maize

Qian Cai1,2, Yulong Zhang1, Zhanxiang Sun2, Jiaming Zheng2, Wei Bai2, Yue Zhang3, Yang Liu2, Liangshan Feng2, Chen Feng2, Zhe Zhang2, Ning Yang2, Jochem B. Evers4, and Lizhen Zhang3 Qian Cai et al.
  • 1College of Land and Environment, Shenyang Agricultural University, Shenyang, 110161, Liaoning, China
  • 2Tillage and Cultivation Research Institute, Liaoning Academy of Agricultural Sciences, Shenyang, 110161, Liaoning, China
  • 3College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China
  • 4Wageningen University, Centre for Crop Systems Analysis (CSA), Droevendaalsesteeg 1, 6708 PB Wageningen, the Netherlands

Abstract. A large yield gap exists in rain-fed maize (Zea mays L.) production in semi-arid regions, mainly caused by frequent droughts halfway through the crop-growing period due to uneven distribution of rainfall. It is questionable whether irrigation systems are economically required in such a region since the total amount of rainfall does generally meet crop requirements. This study aimed to quantitatively determine the effects of water stress from jointing to grain filling on root and shoot growth and the consequences for maize grain yield, above- and below-ground dry matter, water uptake (WU) and water use efficiency (WUE). Pot experiments were conducted in 2014 and 2015 with a mobile rain shelter to achieve conditions of no, mild or severe water stress. Maize yield was not affected by mild water stress over 2 years, while severe stress reduced yield by 56 %. Both water stress levels decreased root biomass slightly but shoot biomass substantially. Mild water stress decreased root length but increased root diameter, resulting in no effect on root surface area. Due to the morphological plasticity in root growth and the increase in root ∕ shoot ratio, WU under water stress was decreased, and overall WUE for both above-ground dry matter and grain yield increased. Our results demonstrate that an irrigation system might be not economically and ecologically necessary because the frequently occurring mild water stress did not reduce crop yield much. The study helps us to understand crop responses to water stress during a critical water-sensitive period (middle of the crop-growing season) and to mitigate drought risk in dry-land agriculture.

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Short summary
Large yield gaps exist in rain-fed maize in semi-arid regions caused by frequent droughts halfway through the growing period due to uneven distribution of rainfall. It can be questioned whether irrigation systems are economically and ecologically required. Maize yield was not affected by mild water stress due to the morphological plasticity in root growth. Our results help to mitigate drought risk in dry-land agriculture.
Large yield gaps exist in rain-fed maize in semi-arid regions caused by frequent droughts...
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