Abstract
The root system plays an important role in the growth and development of cotton, and root growth is closely related to shoot growth, both of which are affected by N availability in the soil. However, it is unknown how N affects root growth and the root–shoot relationship under various N rates in the Yellow River Basin, China. Thus, the aim of this study was to assess the impacts of the application rate of N on root growth and the root–shoot relationship, to provide insight into the N regulation of root and shoot growth and N efficiency from the perspective of the root system. A field experiment conducted in 2014 and 2015 was used to determine the effects of N rates (0, 120, 240, and 480 kg ha–1) on root morphology, root distribution, the root–shoot relationship, and cotton yield. A moderate N fertilization rate (240 kg ha–1) increased root length, root surface area, and root biomass in most soil layers and significantly increased total root growth and total root biomass by more than 36.06% compared to the 0 kg ha–1 treatment. In addition, roots in the surface soil layers were more strongly affected by N fertilization than roots distributed in the deeper soil layers. Total root length, total root surface area, and root biomass in the 0–15 cm layer were significantly correlated with shoot biomass and boll biomass. In the 60–75 cm layer, total root length, total root surface area, and root length were significantly positively correlated with seed cotton yield. The application of a moderate level of N markedly increased total shoot biomass, boll biomass, and seed cotton yield. Our results show that increased shoot and boll biomasses were correlated with a significant increase in the root system especially the shallow roots in the moderate N treatment (240 kg ha–1), leading to an increase in cotton seed yield.
Highlights
The root system is the main organ for nutrient absorption in plants, and it can synthesize and transport physiological activators (Tian et al, 2009; Mohd et al, 2013)
This study revealed how N affects cotton root morphology and distribution, as well as how the root system affects shoot biomass and cotton seed yield
We showed that root systems were larger under moderate and high N fertilization rates than under other treatments
Summary
The root system is the main organ for nutrient absorption in plants, and it can synthesize and transport physiological activators (Tian et al, 2009; Mohd et al, 2013). Nitrogen Fertilization Increases Root Growth and development (King et al, 2003; Fahong et al, 2004). Shootto-root mobile CEPD-like 2 evalutaes shoot N status to systemically regulate nitrate uptake in Arabidopsis (Ota et al, 2020). Moderate N treatment (240 kg ha−1) coordinate root and shoot development. Grain yield and N use efficiency are positively correlated with the active absorption area, and negatively correlated with the root-to-shoot ratio, after the midtillering stage in rice (Xu et al, 2018). The root system has attracted increasing attention (Lynch, 2007; Ren et al, 2018), with studies focusing on the factors which affect root growth and distribution (Nacry et al, 2013) and the changes in the root-shoot system due to irrigation, fertilization, and straw management K. et al, 2018), among which N fertilization has been regarded as the key factor in root system development
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
