• Spectroscopy and Spectral Analysis
  • Vol. 40, Issue 2, 535 (2020)
ZHANG Yue1, TIAN Yuan-sheng1, SUN Wen-yi1、2, MU Xing-min1、2, GAO Peng1、2, and ZHAO Guang-ju1、2
Author Affiliations
  • 1[in Chinese]
  • 2[in Chinese]
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    DOI: 10.3964/j.issn.1000-0593(2020)02-0535-08 Cite this Article
    ZHANG Yue, TIAN Yuan-sheng, SUN Wen-yi, MU Xing-min, GAO Peng, ZHAO Guang-ju. Effects of Different Fertilization Conditions on Canopy Spectral Characteristics of Winter Wheat Based on Hyperspectral Technique[J]. Spectroscopy and Spectral Analysis, 2020, 40(2): 535 Copy Citation Text show less

    Abstract

    Quantitative study of the relationship between soil nutrient content and canopy spectral characteristics of winter wheat based on hyperspectral techniques can provide theoretical basis and technical support for winter wheat nutrient abundance monitoring and scientific and rational guidance of fertilization programs. In a 35-year long-term positioning experiment, the effects of different fertilization treatments on the spectral characteristics of winter wheat canopy in different growth stages of Loess Plateau were studied. The results showed that under single fertilization conditions, compared with no fertilization (CK), from the jointing stage to the heading stage of the winter wheat, the CR500, CR670 and CR550 values of single P application were higher, while the spectral reflectance of single N and M application was significantly lower. The CR500 values of single P, N and M application in jointing stage were 1.2 times, 74.9% and 70.5% of CK; CR670 values were 1.2 times, 66.8% and 62.6% of CK; CR550 values were 1.2 times, 76.2% and 76.9% of CK, respectively. The peaks and valleys of the reflex characteristics of winter wheat were significantly enhanced at heading stage than those at jointing stage, at heading stage, the CR500 values of P, N and M application were 1.2 times, 81.0% and 53.5% of CK; the CR670 values were 1.3 times, 76.8% and 40.6% of CK; CR550 values were 1.2 times, 78.5% and 63.4% of CK, respectively. At the filling stage, the peaks and valleys of the reflex characteristics of each treatment were obviously weakened; to the maturity stage, the difference between the peaks and valleys of the winter wheat spectrum under different fertilization treatments was no longer obvious. The spectral characteristics of the red band position absorption valley under single fertilization conditions after enveloping line removal showed that, except for the maturity period, the red band absorption valley area (A), the red band absorption valley left area (AL) and the absorption peak symmetry (S) of winter wheat with single P application were higherthan CK, both with N and Mapplication were lower than CK. Under the combined fertilization conditions, the NMP, NP and NM of all nitrogen application combinations showed similar patterns, and the red, blue absorption depth and green reflection peak and the near-infrared spectral reflectance in the visible light range were significantly lower than CK; the spectral reflectance eigenvalue of the PM combined treatment was slightly lower than CK. Compared with CK, the characteristic value of spectral reflectance of PM combined treatment was slightly lower from the jointing stage to the heading stage; the difference between the spectral reflectance values of NM, NPM and NP treatment was small but significantly lower than CK. The CR500 values of NM, NPM and NP treatment were 25.85%, 27.99% and 26.07% of CK; CR670 values were 12.56%, 13.27% and 13.98% of CK; CR550 values were 33.39%, 35.38% and 37.04% of CK, respectively. The CR500, CR670 and CR550 values of PM treatment were 67.52%, 55.69% and 79.40% of CK, respectively. At grain filling stage, the peaks and valleys of each treatment were significantly weaker than those at heading stage. At maturity stage, the spectral reflectance absorption characteristics of different fertilization treatments were not significantly different, but they were significantly lower than CK. The spectral characteristics of red band absorption valley under combined fertilization conditions after enveloping line removal showed that the area of red band absorption valley (A) of the winter wheat was the largest in CK, followed by PM treatment and NM treatment.
    ZHANG Yue, TIAN Yuan-sheng, SUN Wen-yi, MU Xing-min, GAO Peng, ZHAO Guang-ju. Effects of Different Fertilization Conditions on Canopy Spectral Characteristics of Winter Wheat Based on Hyperspectral Technique[J]. Spectroscopy and Spectral Analysis, 2020, 40(2): 535
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