Espectroscopia de reflectância &lt;i&gt;in situ &lt;/i&gt;na avaliação da resposta da adubação nitrogenada em cana-de-açúcar

Tavares, Tiago Rodrigues

doi:10.11606/d.11.2017.tde-09082017-164610

Cited by 1 publication

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“…Tendo em conta que os índices (mND705, mNDVI, MTCI, NDRE, RI-1dB, RI-2dB, RI-3dB, RI-half e SR705) foram projetados especificamente para a cultura que os autores estavam trabalhando, os resultados demonstraram boa performance na predição dos teores de nitrogênio foliar em forrageiras nos estudos de Martins (2016), Tavares (2017) e no presente trabalho.…”

Section: Influência Fisiológica Do Nitrogênio Sobre a Plantaunclassified

Análise hiperespectral de folhas de >i<Brachiaria brizantha>/i< cv. Marandú submetidas a doses crescentes de nitrogênio

Takushi¹

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Hyperspectral analysis of Brachiaria brizantha cv. Marandú leaves under contrasting nitrogen levels Remote sensing is a set of techniques that can help to monitor pasture quality. The object of this study is to analyze the spectral response from Brachiaria brizantha cv. Marandú leaves, under contrasting nitrogen levels, to differentiate and predict leaf nitrogen content. The treatments were set in a Randomized Block Design, composed of four blocks and four treatments, totaling 16 plots. Increasing doses of urea fertilization were used: 0, 25, 50, 75 kg N/ha/mowing. During the experiment, 7 data collections were performed, and 8 leaves per plot were extracted for each data collection. These leaves were submitted to hyperspectral data extraction and subsequent chemical analysis to quantify the nitrogen content. When analyzing the spectral pattern of the leaves, statistical differences among samples with different nitrogen levels were noticeable in the visible range of the spectrum in all the collections, with emphasis on the 550 nm region (green). Through linear discriminant analysis (LDA), performed for each collection, the generated centroids by the samples of each nitrogen level presented significant differences, except for LD1 in collections 6 and 7, which did not present a distinction between treatments of 50 and 75 kg of N/ha/mowing, and LD2 in collection 5 that did not distinguish between treatments of 0 and 50 kg of N/ha/mowing. The partial least square regression (PLSR) method generated reasonable to good values of R² (0.53 to 0.83) for the prediction of leaf nitrogen content, where the wavelengths with the highest coefficient in these models are in the red edge region of the spectrum (715 to 720 nm). Finally, when testing the performance of some Vegetation Indexes from literature, collections 4, 6 and 7 presented good determination coefficients (R²) ranging from 0.65 to 0.73; a common feature in the indexes that best estimate the nitrogen content is the presence of wavelengths from the red edge region of the spectrum.

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Section: Influência Fisiológica Do Nitrogênio Sobre a Plantaunclassified

Análise hiperespectral de folhas de >i<Brachiaria brizantha>/i< cv. Marandú submetidas a doses crescentes de nitrogênio

Takushi¹

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Espectroscopia de reflectância <i>in situ </i>na avaliação da resposta da adubação nitrogenada em cana-de-açúcar

Abstract: Espectroscopia de reflectância in situ na avaliação da resposta da adubação nitrogenada na cana-de-açúcar/ Tiago Rodrigues Tavares.-versão revisada de acordo com a resolução CoPGr 6018 de 2011.

Cited by 1 publication

References 48 publications

Análise hiperespectral de folhas de >i<Brachiaria brizantha>/i< cv. Marandú submetidas a doses crescentes de nitrogênio

Análise hiperespectral de folhas de >i<Brachiaria brizantha>/i< cv. Marandú submetidas a doses crescentes de nitrogênio

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