|
|
|
|
|
|
Study on Moisture Content of Soybean Canopy Leaves under Drought Stress Using Terahertz Technology |
ZHAO Xu-ting1, 2, 3, ZHANG Shu-juan1, LI Bin2, 3, 4*, LI Yin-kun5 |
1. College of Engineering, Shanxi Agricultural University, Taigu 030801, China
2. Beijing Research Center for Information Technology in Agriculture, Beijing 100097, China
3. Key Laboratory of Quantitative Remote Sensing in Agriculture, Ministry of Agriculture, Beijing 100097, China
4. Beijing Key Lab of Digital Plant, Beijing 100097, China
5. Beijing Research Center of Intelligent Equipment for Agriculture, Beijing 100097, China |
|
|
Abstract With the increasingly serious situation of water resources shortage, the shortage of agricultural irrigation water in some areas has resulted in reduction of crop and damages the farmers’ interests. Soybean is kind of crop with high water requirement. Once the water deficiency will directly affect the morphology and growth, the quality and the yield will be reduced. Because water status of soybean leaves can truly reflect the degree of soil water deficit, a tool for water content measurements is in great need. The strong attenuation of terahertz radiation in water makes it a contactless probe, which can be used to detect the water status of leaves quickly. As a result, terahertz spectroscopy technology was studied to rapidly and conveniently estimate water content in soybean canopy leaf, so as to monitor the health status in real time. Zhong-huang 13 soybean cultivars were cultivated in our experiment. In order to simulate the drought stress of different degrees in the field, 5 different gradients of flowering soybean were carried out: normal watering, mild drought stress and moderate drought, severe drought, more severe drought stress (accounted for 80%, 65%, 50%, 35%, 20% of the maximum water holding capacity in the field, respectively) and 3 repetitions were set per gradient. The artificial weighing method combined with the portable soil moisture measuring instrument was used to regulate soil moisture content to meet the requirements of the various water gradients . Then, the experimental soybean were transported to the laboratory, and the samples were scanned by terahertz time domain spectrometer. 18 canopy leaves for each gradient, a total of 90 samples were collected. It was divided into calibration set and prediction set at 2∶1 ratio. After obtaining the time domain spectral data of each sample, the absorption coefficient spectrum and the refractive index spectrum of each sample were calculated by the data processing method of Dorney and Duvillaret. The changes of time domain spectroscopy, absorption coefficient and refractive index with water drought stress were qualitatively analyzed. It was found that the peak value of time domain spectrum was decreasing with the degree of water stress decreasing, which was lower than the reference value. At the same time, there was a significant time delay. The number of absorption coefficient gradually decreased with the aggravation of drought stress, and the refractive index value the same decreased. Moreover, partial least squares (PLS) and multiple linear regression (MLR) were used to quantitatively study the correlation between time domain spectrum, absorption coefficient, refractive index spectrum data and leaf water content, respectively. The results showed that, terahertz was sensitive to differences of leaf water content. And the MLR model based on maximum and minimum values in time domain spectral performed the best, in which correlation coefficient (rP) and root mean square error of prediction set (RMSEP) were -0.939 3 and 0.049 5, respectively. This study showed that the application of terahertz technology in leaf water content estimation has good feasibility. It will provide a new detection tool and experimental basis for rapid monitoring of water content in soybean canopy and scientific water-saving irrigation management.
|
Received: 2017-12-26
Accepted: 2018-04-12
|
|
Corresponding Authors:
LI Bin
E-mail: lib@nercita.org.cn
|
|
[1] RUAN Ying-hui, DONG Shou-kun, LIU Li-jun,et al(阮英慧, 董守坤, 刘丽君, 等) . Soybean Science(大豆科学), 2012, 31(3): 385.
[2] LI Meng-qi, TAN Zhi-yong, QIU Fu-cheng,et al(李孟奇, 谭智勇, 邱付成, 等) . Acta Optica Sinica(光学学报), 2017, 37(6): 0611004.
[3] SHI Jing, WANG Xin-ke, ZHENG Xian-hua,et al(石 敬, 王新柯, 郑显华, 等). Chinese Optics(中国光学), 2017, 10(1): 131.
[4] Ralf G, Martin K. Plant Methods, 2015, 11(1): 15.
[5] Gente R, Born N, Voss N, et al. Journal of Infrared Millimeter and Terahertz Waves, 2013, 34(3-4):316.
[6] Castro-Camus E, Palomar M, Covarrubias A A. Scientific Report, 2013, 3: 2910.
[7] LONG Yuan, ZHAO Chun-jiang, LI Bin(龙 园, 赵春江, 李 斌). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2017, 37(10): 3027.
[8] YANG Hang, ZHAO Hong-wei, ZHANG Jian-bing,et al(杨 航, 赵红卫, 张建兵, 等). Journal of Infrared Millimeter Waves(红外与毫米波学报), 2014, 33(3): 263.
[9] MA Pin, YANG Yu-ping(马 品, 杨玉平). Journal of Terahertz Science and Electronic Information Technology(太赫兹科学与电子信息学报), 2107, 15(1): 26. |
[1] |
CHEN Ying1, ZHAO Zhi-yong1, HE Lei1, HAN Shuai-tao1, ZHU Qi-guang2, ZHAI Ying-jian3, LI Shao-hua3. Resonance Spectral Characteristic and Refractive Index Sensing Mechanism of Surface Coated Waveguide Grating[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2018, 38(07): 2320-2324. |
[2] |
LUO Wei1,2, SUN Feng-long1,2, LIU Jia-rui3, HOU Jun-wu1,2, WANG Ben-gan1,2, HUANG Xiao-ping1,2. Matrix Measurement of Glucose Concentration Based on Surface Plasmon Resonance Sensor[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2018, 38(06): 1982-1986. |
[3] |
ZHANG Xiao-xuan1, CHANG Tian-ying1, 2*, GUO Qi-jia1, LIU Ling-yu2, CUI Hong-liang1. Terahertz Optical Parameters Measurement and Error Analysis of Special Engineering Plastic[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2018, 38(05): 1368-1374. |
[4] |
ZHANG Hai-wei1, 2, ZHANG Fei1, 2, 3*, ZHANG Xian-long 1, 2, LI Zhe1, 2, Abduwasit Ghulam1, 4, SONG Jia1, 2. Inversion of Vegetation Leaf Water Content Based on Spectral Index[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2018, 38(05): 1540-1546. |
[5] |
YAN Fang, ZOU Liang-hui*,WANG Zhi-chun*. Detection of Adsorption for Heavy Metals Ions Based on Terahertz Time Domain Spectroscopy[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2018, 38(04): 1044-1048. |
[6] |
JIANG Qiang1,WANG Yue2*,WEN Zhe3,WANG Ji-hua4. Moisture Content Determination of Transformer Oil by Using Terahertz Time-Domain Spectroscopy[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2018, 38(04): 1049-1052. |
[7] |
CHEN Xi-ai1,2,3, WU Xue1, ZHANG Song1, WANG Ling1. Study of Plant Growth Regulators Detection Technology Based on Terahertz Spectroscopy[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2018, 38(03): 665-669. |
[8] |
QI Hai-jun1, 2, Karnieli Arnon2, LI Shao-wen1*. Predicting Soil Available Nitrogen with Field Spectra Corrected by Y-Gradient General Least Square Weighting[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2018, 38(01): 171-175. |
[9] |
GUAN Ai-hong1,2, LI Zhi1,2, GE Hong-yi1,2. The Qualitative and Quantitative Detection of Potassium Alum in Sweet Potato Starch Based on Terahestz Time-Domain Spectroscopy[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2018, 38(01): 267-270. |
[10] |
ZHANG Qi, FANG Hong-xia, ZHANG Hui-li, QIN Dan, HONG Zhi, DU Yong*. Terahertz Spectroscopy and Density Functional Theory Investigation of 2-Thiobarbituric Acid Polymorphs[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2017, 37(12): 3677-3682. |
[11] |
WU Zhi-kui, BAO Ri-ma*, WANG Fang, MIAO Xin-yang, FENG Cheng-jing. Application of Terahertz Time-Domain Spectroscopy in Fluid Inclusion Study[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2017, 37(12): 3689-3692. |
[12] |
ZHANG Qi, FANG Hong-xia, ZHANG Hui-li, QIN Dan, HONG Zhi, DU Yong*. Vibrational Spectroscopic Characterization of the Co-Crystal and the Forming Condition between γ-Aminobutyric Acid and Benzoic Acid[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2017, 37(12): 3786-3792. |
[13] |
LI Le, HU Yi-hua*, GU You-lin,ZHAO Yi-zheng, YU Lei, HUANG Bao-kun. Infrared Extinction Performance of Biological Materials[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2017, 37(11): 3430-3434. |
[14] |
HUANG Yu1, SUN Ping1*, ZHANG Zheng1, JIN Chen1, LIU Wei2, WANG Wen-ai2. Experimental Study on Terahertz Spectrum of Lacidipine
[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2017, 37(08): 2356-2359. |
[15] |
LI Bin1, 2, 3, LONG Yuan1, 2, 3, LIU Hai-shun4, ZHAO Chun-jiang1, 2, 3, 5*. The Determination of Glucose Based on Terahertz Spectroscopy[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2017, 37(07): 2165-2170. |
|
|
|
|