Abstract
The roots are a vital organ for plant growth and health. The opaque surrounding environment of the roots and the complicated growth process means that in situ and non-destructive root phenotyping face great challenges, which thus spur great research interests. The existing methods for root phenotyping are either unable to provide high-precision and high accuracy in situ detection, or they change the surrounding root environment and are destructive to root growth and health. Thus,we propose and develop an ultra-wideband microwave scanning method that uses time reversal to achieve in situ root phenotyping nondestructively. To verify the method’s feasibility, we studied an electromagnetic numerical model that simulates the transmission signal of two ultra-wideband microwave antennas. The simulated signal of roots with different shapes shows the proposed system’s capability to measure the root size in the soil. Experimental validations were conducted considering three sets of measurements with different sizes, numbers and locations, and the experimental results indicate that the developed imaging system was able to differentiate root sizes and numbers with high contrast. The reconstruction from both simulations and experimental measurements provided accurate size estimation of the carrots in the soil, which indicates the system’s potential for root imaging.
Highlights
Publisher’s Note: MDPI stays neutralAs one of the plant’s three major organs, the root system provides functions that are central to plant fitness, such as nutrient absorption, fixation, water transmission, synthesis and storage [1]
The microwave imaging method is a promising nondestructive evaluation technique that can provide a quantitative measure of the lossless or low-loss dielectric materials profile
A Vivaldi antenna array operating at ultra-wideband frequency from 3 to 10 GHz and providing high gain and symmetric beam-patterns was designed in accordance with [39] to detect roots buried in the soil in situ based on the properties of Time Reversal (TR)
Summary
As one of the plant’s three major organs, the root system provides functions that are central to plant fitness, such as nutrient absorption, fixation, water transmission, synthesis and storage [1]. A better understanding of root phenotype in situ and non-destructively is important for the research of soil and plant science, earth system science and others. The long-term radiation effects on the plant root growth and the complexity and inconvenience of the equipment makes the neutron radiography method inapplicable for in situ root phenotyping. Since 2000, high-precision optical instruments and digital imaging methods have greatly improved the accuracy of root imaging technology and made non-destructive root phenotyping possible. The X-ray computed tomography method can achieve non-destructive, high resolution, high accuracy and fast 3D root phenotyping [17–19]. The hyperspectral imaging method [9] are all limited to real soil as the laser scanner is. The microwave imaging method is a promising nondestructive evaluation technique that can provide a quantitative measure of the lossless or low-loss dielectric materials profile
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.
