Teor foliar de nitrogênio em videira fertirrigada e sua relação com atributos do solo e da planta
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Data
2020-02-19
Autores
Silva, Thassio Monteiro Menezes da
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Universidade Estadual Paulista (Unesp)
Resumo
Sensores podem auxiliar no monitoramento do nitrogênio no tecido foliar e da água no solo, mas para esse propósito eles necessitam ser calibrados. Assim, o presente trabalho teve como objetivo propor um procedimento para o uso do clorofilômetro em ma área de produção comercial de uva para vinho, no contexto da vitivinicultura de precisão, avaliando a variabilidade temporal do teor de nitrogênio foliar e as suas relações com as zonas homogêneas de solo e da planta. O estudo foi desenvolvido no município de Espirito Santo do Pinhal, estado de São Paulo, no ciclo de produção de 2019 de um vinhedo com a cv. Chardonnay sobre o porta-enxerto Paulsen 1103. O vinhedo foi irrigado e fertirrigado por um sistema de irrigação por gotejamento. O equipamento HS2 HydroSense, calibrado para diferentes zonas homogêneas quanto a fração granulométrica do solo, foi utilizado em 6 datas durante o ciclo de produção para a determinação do conteúdo de água a 0-20 cm de profundidade, e em 20 pontos por zona. O índice relativo de clorofila foi medido pelo clorofilômetro ClorofiLOG CFL 1030 em 4 datas durante o ciclo de produção, e em 40 plantas por data. Para a calibração do clorofilômetro, amostras de folhas foram coletadas para a determinação em laboratório dos teores de clorofila e de nitrogênio. A produção por planta, número de cachos por planta, massa média de cachos por planta e produtividade da área total foram determinados. A maturação tecnológica das bagas foi observada por amostragens periódicas de bagas para a determinação do pH, ácido málico e sólidos solúveis. A partir dos modelos gerados, o clorofilômetro foi capaz de estimar com precisão satisfatória os teores de clorofila a, b e total, mas para os teores de nitrogênio foliar, a precisão foi menor. Foi possível estimar com elevada precisão a umidade do solo por meio dos modelos matemáticos gerados. As zonas homogêneas de solo apresentaram grande influência sob a umidade do solo, parâmetros da planta e da produção das videiras. As zonas homogêneas de NDVI, medidas com o uso do sensor ativo Crop Circle ACS 430, apresentaram pouca influência sob os parâmetros da planta, sendo mais relacionadas aos aspectos qualitativos das uvas. Os índices relativos de clorofila e os teores de clorofila demonstraram comportamento semelhante ao do nitrogênio foliar, com a interação dos pigmentos com os teores de nitrogênio foliar sendo mais acentuada quando comparadas dentro das zonas homogêneas de solo.
Sensors can assist in monitoring leaf tissue nitrogen and soil water, but for this purpose they need to be calibrated. Thus, the present study aimed to propose a procedure for the use of a chlorophyll meter in a commercial growing area of wine grapes, within the context of precision viticulture, evaluating the temporal variability of leaf nitrogen content and its relationship with homogeneous soil and plant zones. The study was carried out at Espirito Santo do Pinhal, state of São Paulo, Brazil, in the 2019 growing season of vineyard of cv. Chardonnay grifted on Paulsen 1103 rootstock. Plants were irrigated and fertigated by a drip irrigation system. The HS2 HydroSense equipment, calibrated for different homogeneous zone of soil fractions, was used to determine the water content at 0-20 cm depth in 6 days throughout the growing season, at 20 points in each zone. The relative chlorophyll index was measured using the chlorophyll meter ClorofiLOG CFL 1030 in 4 days throughout the growing season, in 40 plants by day. Leaf samples were collected for laboratory determination of chlorophyll and nitrogen contentes and calibration of the chlorophyll meter. The production per plant, number of bunches per plant, average mass of bunches per plant and yield (total area) were determined. The technological maturation was observed by periodic sampling of berries to determination of pH, malic acid and soluble solids in laboratory. From the mathematical models generated, the chlorophyll meter was able to estimate with satisfactory precision the levels of chlorophyll a, b and total, but for the levels of leaf nitrogen, the precision was lower. It was possible to estimate the soil moisture with high precision through the mathematical models generated. The soil homogeneous zones had a great influence on soil moisture, plant parameters and grape production. The homogeneous zones of NDVI, measured with an active sensor (Croip Circle ACS430), showed little influence on the plant parameters, and were more related to the grape qualitative characteristics. The relative chlorophyll indices and chlorophyll contents showed a behavior similar to that of leaf nitrogen, with the interaction of pigments with leaf nitrogen levels being more accentuated when compared within soil homogeneous zones.
Sensors can assist in monitoring leaf tissue nitrogen and soil water, but for this purpose they need to be calibrated. Thus, the present study aimed to propose a procedure for the use of a chlorophyll meter in a commercial growing area of wine grapes, within the context of precision viticulture, evaluating the temporal variability of leaf nitrogen content and its relationship with homogeneous soil and plant zones. The study was carried out at Espirito Santo do Pinhal, state of São Paulo, Brazil, in the 2019 growing season of vineyard of cv. Chardonnay grifted on Paulsen 1103 rootstock. Plants were irrigated and fertigated by a drip irrigation system. The HS2 HydroSense equipment, calibrated for different homogeneous zone of soil fractions, was used to determine the water content at 0-20 cm depth in 6 days throughout the growing season, at 20 points in each zone. The relative chlorophyll index was measured using the chlorophyll meter ClorofiLOG CFL 1030 in 4 days throughout the growing season, in 40 plants by day. Leaf samples were collected for laboratory determination of chlorophyll and nitrogen contentes and calibration of the chlorophyll meter. The production per plant, number of bunches per plant, average mass of bunches per plant and yield (total area) were determined. The technological maturation was observed by periodic sampling of berries to determination of pH, malic acid and soluble solids in laboratory. From the mathematical models generated, the chlorophyll meter was able to estimate with satisfactory precision the levels of chlorophyll a, b and total, but for the levels of leaf nitrogen, the precision was lower. It was possible to estimate the soil moisture with high precision through the mathematical models generated. The soil homogeneous zones had a great influence on soil moisture, plant parameters and grape production. The homogeneous zones of NDVI, measured with an active sensor (Croip Circle ACS430), showed little influence on the plant parameters, and were more related to the grape qualitative characteristics. The relative chlorophyll indices and chlorophyll contents showed a behavior similar to that of leaf nitrogen, with the interaction of pigments with leaf nitrogen levels being more accentuated when compared within soil homogeneous zones.
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Palavras-chave
Irrigação agrícola, Viticultura de precisão, Clorofila análise, Solos umidade medição, Irrigation, Precision viticulture, Chlorophyll analysis, Soil