Photographic measurement of leaf angles in field crops

Xiaochen Zou, Matti Mõttus, Priit Tammeorg, Clara Lizarazo Torres, Tuure Takala, Jan Pisek, Pirjo Mäkelä, F. L. Stoddard, Petri Pellikka

Research output: Contribution to journalArticleScientificpeer-review

38 Citations (Scopus)

Abstract

Leaf angle distribution (LAD) is one of the most important parameters used to describe the structure of horizontally homogeneous vegetation canopies such as field crops. LAD affects how incident photosynthetically active radiation is distributed on plant leaves, thus directly affecting plant productivity. Knowledge of LAD is also required for retrieval of other important biophysical variables from measurements of canopy radiation transmittance or spectral reflectance. Unfortunately, its determination is laborious and measured data is rarely available. In this study, we applied a recently developed method for determination of the inclination angles using leveled digital photography to the leaves of six cool-temperate crops: faba bean, narrow-leafed lupin, turnip rape, wheat, barley, and oat. The method, previously applied only to small and flat leaves of broadleaved trees and bushes, was extended to be applicable to the narrow and curved leaves of cereals. A reasonable match was found between the leaf angles determined by photographic measurements and the mean leaf tilt angles (MTA) measured using a LAI-2000 plant canopy analyzer for five out of the six species (R2=0.92). The error caused by assuming a spherical LAD, when calculating LAI from canopy transmittance measurements, varied between 0 and 1.5 LAI units, depending on species. Finally, we analyzed the correlation between photographically determined species-specific LADs and airborne imaging spectroscopy data acquired for the same species in a similar growth stage. The highest correlation between spectral reflectance factor and leaf mean tilt angle was found at a wavelength of 748nm (R=0.80). The high correlation between MTA and this red edge waveband can be useful for MTA determination from imaging spectroscopy.

Original languageEnglish
Pages (from-to)137-146
Number of pages10
JournalAgricultural and Forest Meteorology
Volume184
DOIs
Publication statusPublished - 15 Jan 2014
MoE publication typeA1 Journal article-refereed

Fingerprint

leaf angle
field crops
crop
canopy
tilt
transmittance
leaves
reflectance
leaf area index
spectroscopy
image analysis
spectral reflectance
Lupinus
turnips
digital images
photosynthetically active radiation
faba beans
oats
wavelengths
barley

Keywords

  • Digital camera
  • Field crops
  • Leaf angle distribution
  • Spectral reflectance

Cite this

Zou, X., Mõttus, M., Tammeorg, P., Torres, C. L., Takala, T., Pisek, J., ... Pellikka, P. (2014). Photographic measurement of leaf angles in field crops. Agricultural and Forest Meteorology, 184, 137-146. https://doi.org/10.1016/j.agrformet.2013.09.010
Zou, Xiaochen ; Mõttus, Matti ; Tammeorg, Priit ; Torres, Clara Lizarazo ; Takala, Tuure ; Pisek, Jan ; Mäkelä, Pirjo ; Stoddard, F. L. ; Pellikka, Petri. / Photographic measurement of leaf angles in field crops. In: Agricultural and Forest Meteorology. 2014 ; Vol. 184. pp. 137-146.
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Zou, X, Mõttus, M, Tammeorg, P, Torres, CL, Takala, T, Pisek, J, Mäkelä, P, Stoddard, FL & Pellikka, P 2014, 'Photographic measurement of leaf angles in field crops', Agricultural and Forest Meteorology, vol. 184, pp. 137-146. https://doi.org/10.1016/j.agrformet.2013.09.010

Photographic measurement of leaf angles in field crops. / Zou, Xiaochen; Mõttus, Matti; Tammeorg, Priit; Torres, Clara Lizarazo; Takala, Tuure; Pisek, Jan; Mäkelä, Pirjo; Stoddard, F. L.; Pellikka, Petri.

In: Agricultural and Forest Meteorology, Vol. 184, 15.01.2014, p. 137-146.

Research output: Contribution to journalArticleScientificpeer-review

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AU - Zou, Xiaochen

AU - Mõttus, Matti

AU - Tammeorg, Priit

AU - Torres, Clara Lizarazo

AU - Takala, Tuure

AU - Pisek, Jan

AU - Mäkelä, Pirjo

AU - Stoddard, F. L.

AU - Pellikka, Petri

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