RT info:eu-repo/semantics/article
T1 Estimation of Leaf Area Index in vineyards by analysing projected shadows using UAV imagery
A1 Vélez Martín, Sergio
A1 Poblete Echeverría, Carlos
A1 Rubio Cano, José Antonio
A1 Vacas Izquierdo, Rubén
A1 Barajas, Enrique
K1 Leaf area index
K1 Shadow detection
K1 Image analysis
K1 Precision agriculture
K1 Machine learning
K1 Spatial variability
K1 Random forest classification
K1 Agricultura
K1 Agriculture
K1 Viticultura
K1 Viticulture
AB A few decades ago, farmers could precisely monitor their croplands just by walking over the fields, but this task becomes more difficult as farm size increases. Precision viticulture can help better understand the vineyard and measure some key structural parameters, such as the Leaf Area Index (LAI). Remote Sensing is a typical approach to monitoring vegetation which measures the spectral information directly emitted and reflected from vegetation. This study explores a new method for estimating LAI which measures the projected shadows of plants using UAV (unmanned aerial vehicle) imagery. A flight mission over a vineyard was scheduled in the afternoon (15:30 to 16:00 solar time), which is the optimal time for the projection of vine shadows on the ground. Real LAI was measured destructively by removing all the vegetation from the area. Then, the projected shadows in the image were detected using machine learning methods (k-means and random forest) and analysed at pixel level using a customised R code. A strong linear relationship (R² = 0.76, RMSE = 0.160 m² m-2 and MAE = 0.139 m² m-2) was found between the shaded area and the LAI per vine. This is a quick and simple method, which is non-destructive and gives accurate results; moreover, flights can be scheduled during other periods of the day than solar noon, such as in the morning or afternoon, thus enabling pilots to extend their working day. Therefore, it may be a viable option for determining LAI in vineyards trained on Vertical Shoot Positioned (VSP) systems.
PB International Viticulture and Enology Society
YR 2021
FD 2021-11
LK http://hdl.handle.net/10259/10062
UL http://hdl.handle.net/10259/10062
LA eng
NO This study was possible thanks to the financial support of Junta de Castilla y León (Spain), the project INIA RTA2014- 00077-C02, FPI-INIA2016-017 and FEDER funding.
DS Repositorio Institucional de la Universidad de Burgos
RD 06-feb-2025