ABSTRACT
Remote sensing through band ratio techniques for nutritional monitoring of clonal eucalyptus plantations is essential to guarantee health and productivity, reducing costs of forestry enterprises. The objective was to apply vegetation indices from high resolution satellite images in the nutritional diagnosis of macronutrients in plantations of clonal hybrids of Eucalyptus urophylla S. T. Blake. The study was carried out in 62 areas of six municipalities in the state of Bahia under cultivation of homogeneous eucalyptus plantations, aged between 1.3 and 1.8 years. The design was completely randomized with six treatments constituted by the rainfall regime (1000 to 1300 mm year-1 and 1300 to 1600 mm year-1) and soil types (class and texture). The nutritional diagnosis of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg) and sulfur (S) was performed from leaf analysis and determination of vegetation indices: normalized difference vegetation (NDVI), normalized difference water index (NDWI) and soil adjusted vegetation index (SAVI). The evaluated areas have high vigor (NDVI > 0.70) and the highest values were observed in the rainy regions (1300 to 1600 mm year-1) (mean of 0.78). The NDWI index presents the highest correlation for the average levels of Ca and Mg. The NDVI, NDWI and SAVI indexes present a strong correlation with each other (-0.97 to 1.00) and can help in mapping vigor and consequently in eucalyptus productivity.
Keyword
Forest management; Remote sensing; Macronutrients
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