Dris calculation methods for evaluating the nutritional status of oil palm in the Eastern Amazon |
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Authors: | Gilson Sergio Bastos De Matos Antonio Rodrigues Fernandes Paulo Guilherme Salvador Wadt Vinícius Ide Franzini Elmecelli Moraes De Castro Souza Helen Monique Nascimento Ramos |
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Institution: | 1. Federal Rural University of Amazonia, Av. Presidente Tancredo Neves, Belém, Pará, Brazilgilsonsbm@yahoo.com.br;3. Federal Rural University of Amazonia, Av. Presidente Tancredo Neves, Belém, Pará, Brazil;4. Embrapa Rond?nia, Porto Velho, Rond?nia, Brazil;5. Embrapa Eastern Amazon, Trav. Enéas Pinheiro, Belém, Pará, Brazil;6. World Agroforestry Centre – ICRAF, Trav. Enéas Pinheiro, Belém, Pará, Brazil |
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Abstract: | This study aimed to evaluate six Diagnosis and Recommendation Integrated System (DRIS) calculation methods, including two ways to choose the nutrient ratio F (Letzsch) or R (Nick) values] combined with three functions (Beaufils, Jones, or Elwali and Gascho), and to generate nutritional diagnoses for oil palm. A total of 144 foliar samples in 33 plots in the Eastern Amazon, Brazil, were used. Except for potassium (K) in all calculation methods, the DRIS indices showed no correlation with soil nutrients. Regardless of the formula, the nutritional balance index correlated with the productivity (significant r values) and similar diagnostics were obtained. These diagnoses were reliable according to the chi-square test (χ2), and most observed frequencies presented χ2 calculated less than χ2 tabulated. The average frequencies of samples with nutrient deficiency were 51%, 42%, 37%, 35%, 32%, 30%, 30%, 25%, 20%, 12%, and 12% for samples with nitrogen (N), boron (B), manganese (Mn), sulfur (S), K, copper (Cu), iron (Fe), zinc (Zn), calcium (Ca), phosphorus (P), and magnesium (Mg), respectively. All tested DRIS methods may be used, and their diagnoses indicate the most common nutritional deficiencies in oil palm. |
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Keywords: | Elaeis guineensis Jacq Elaeis oleifera x Elaeis guineensis macronutrients micronutrients soil fertility |
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