Estimating Pasture Biomass and Canopy Height in Brazilian Savanna Using UAV Photogrammetry

oleh: Juliana Batistoti, José Marcato Junior, Luís Ítavo, Edson Matsubara, Eva Gomes, Bianca Oliveira, Maurício Souza, Henrique Siqueira, Geison Salgado Filho, Thales Akiyama, Wesley Gonçalves, Veraldo Liesenberg, Jonathan Li, Alexandre Dias

Format: Article
Diterbitkan: MDPI AG 2019-10-01

Deskripsi

The Brazilian territory contains approximately 160 million hectares of pastures, and it is necessary to develop techniques to automate their management and increase their production. This technical note has two objectives: First, to estimate the canopy height using unmanned aerial vehicle (UAV) photogrammetry; second, to propose an equation for the estimation of biomass of Brazilian savanna (Cerrado) pastures based on UAV canopy height. Four experimental units of <i>Panicum maximum</i> cv. BRS Tamani were evaluated. Herbage mass sampling, height measurements, and UAV image collection were simultaneously performed. The UAVs were flown at a height of 50 m, and images were generated with a mean ground sample distance (GSD) of approximately 1.55 cm. The forage canopy height estimated by UAVs was calculated as the difference between the digital surface model (DSM) and the digital terrain model (DTM). The R<sup>2</sup> between ruler height and UAV height was 0.80; between biomass (kg ha<sup>&#8722;1</sup> GB&#8212;green biomass) and ruler height, 0.81; and between biomass (kg ha<sup>&#8722;1</sup> GB) and UAV height, 0.74. UAV photogrammetry proved to be a potential technique to estimate height and biomass in Brazilian <i>Panicum maximum</i> cv. BRS Tamani pastures located in the endangered Brazilian savanna (Cerrado) biome.