Title

Maize crop coefficient estimation based on spectral vegetation indices and vegetation cover fraction derived from UAV-based multispectral images

Author

MARIANA DE JESUS MARCIAL PABLO

RONALD ERNESTO ONTIVEROS CAPURATA

WALDO OJEDA BUSTAMANTE

Access level

Open Access

License

http://creativecommons.org/licenses/by-nc-nd/4.0

Subjects

Grado de crecimiento diario - (AUTOR) Gestión del riego - (AUTOR) Percepción remota - (AUTOR) Análisis de imágenes basado en objetos - (AUTOR) CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA - (CTI)

Summary or description

DOI: https://doi.org/10.3390/agronomy11040668

Remote sensing-based crop monitoring has evolved unprecedentedly to supply multispectral imagery with high spatial-temporal resolution for the assessment of crop evapotranspiration (ETc). Several methodologies have shown a high correlation between the Vegetation Indices (VIs) and the crop coefficient (Kc). This work analyzes the estimation of the crop coefficient (Kc) as a spectral function of the product of two variables: VIs and green vegetation cover fraction (fv). Multispectral images from experimental maize plots were classified to separate pixels into three classes (vegetation, shade, and soil) using the OBIA (Object Based Image Analysis) approach. Only vegetation pixels were used to estimate the VIs and fv variables. The spectral Kcfv:VI models were compared with Kc based on Cumulative Growing Degree Days (CGDD) (Kc-cGDD). The maximum average values of Normalized Difference Vegetation Index (NDVI), WDRVI, and EVI2 indices during the growing season were 0.77, 0.21, and 1.63, respectively. The results showed that the spectral Kcfv:VI model showed a strong linear correlation with Kc-cGDD (R2 > 0.80). The model precision increases with plant densities, and the Kcfv:NDVI with 80,000 plants/ha had the best fitting performance (R2 = 0.94 and RMSE = 0.055). The results indicate that the use of spectral models to estimate Kc based on high spatial and temporal resolution UAV-images, using only green pixels to compute VI and fv crop variables, offers a powerful and simple tool for ETc assessment to support irrigation scheduling in agricultural areas.

Publisher

Multidisciplinary Digital Publishing Institute

Publish date

2021

Publication type

Article

Information Resource

http://hdl.handle.net/20.500.12013/2259

Format

application/pdf

Source

Agronomy (2073-4395), 11, 668

Language

Spanish

Source repository

Repositorio institucional del IMTA

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