Níveis críticos e faixas de suficiência de nutrientes derivados de métodos de avaliação do estado nutricional da palma-de-óleo

Abstract

Resumo -O objetivo deste trabalho foi determinar níveis críticos e faixas de suficiência de nutrientes para a palma-de-óleo (Elaeis spp.), a partir de métodos de avaliação do estado nutricional das plantas. Utilizaram-se os métodos chance matemática (ChM), sistema integrado de diagnose e recomendação (DRIS) e diagnose da composição nutricional (CND), além da avaliação do nível crítico obtido pela distribuição normal reduzida (DNR) em dados de produtividade e do teor de nutrientes de 144 amostras foliares de plantios no Pará. As regressões dos índices DRIS e CND com os teores foliares foram todas significativas, e o menor coeficiente de determinação foi encontrado para N. Os intervalos das faixas de suficiência obtidos com os métodos ChM, DRIS e CND nos talhões nutricionalmente equilibrados foram, em geral, mais estreitos do que os reportados na literatura, com poucos diagnósticos concordantes, sobretudo para K. Os níveis críticos obtidos pela DNR situaram-se dentro do intervalo das faixas nutricionais obtidas com os outros métodos. Os métodos ChM, DRIS, CND e DNR são adequados para a obtenção de valores de referência nutricionais e indicaram N, Ca, S, Mn e Zn como os nutrientes com maior frequência de deficiência nos talhões de palma-de-óleo avaliados.Termos para indexação: Elaeis guineensis, Elaeis oleifera, chance matemática, diagnose da composição nutricional, DRIS, nutrição de plantas. Critical levels and nutrient sufficiency ranges derived from methods for assessing the nutritional status of oil palmAbstract -The objective of this work was to determine critical levels and nutrient sufficiency ranges for oil palm (Elaeis spp.), using methods for assessing the nutritional status of the plants. The methods of mathematical chance (ChM), diagnosis and recommendation integrated system (DRIS), and compositional nutrient diagnosis (CND), besides the critical level obtained by the reduced normal distribution (DNR), were used in productivity data and in nutrient content of 144 leaf samples of oil palm plantations in the state of Pará, Brazil. The regressions of the DRIS and CND indexes with leaf nutrient contents were all significant, and the lowest coefficient of determination was found for N. The sufficiency range intervals obtained with the ChM, DRIS, and CND methods in the nutritionally balanced stands were, in general, narrower than the ones reported in the literature, with few concordant diagnostics, mainly for K. The critical levels obtained with DNR were within the nutritional range intervals obtained with the other methods. ChM, DRIS, CND, and DNR are suited methods for obtaining nutritional reference values, and they indicated N, Ca, S, Mn, and Zn as the nutrients with the highest frequency of deficiency in the evaluated oil palm orchards.

Productivity and nutrition of fertigated açaí palms according to boron fertilization

“…Higher levels of B, when applied via fertigation, are possibly related to more fractional application and greater availability of water in the summer, due to irrigation, which increases absorption efficiency. Studies in the state of Pará revealed levels of nearly 30 mg kg -1 in leaves of oil palm samples (MATOS et al, 2016) and 15 to 20 mg kg -1 in coconut leaves (SALDANHA et al, 2017) in productive phase. In soils of Kerala, India, the critical variation of B was 7.50 to 13.27 mg kg -1 in the leaves of coconut trees (MATHEW et al, 2018).…”

Micronutrients Concentrations in Leaves of Oil Palm Trees Fertilized with Phosphorus, Potassium, and Magnesium

“…The B concentration in leaves of oil palm trees did not respond significantly to P sources in the years evaluated (Figure 2d). Matos et al (2016) carried out a study with oil palm in eastern Amazon and determined the critical concentration of 24.3 mg kg -1 of B for young plants (<6 years of age) and of 22.7 mg kg -1 of B for adult plants (≥ 6 years old). Thus, B concentrations in leaves reached the critical level determined for the crop with both sources of P applied only in the twelfth year of the plant crop.…”

“…There is little information available on micronutrients in oil palm trees, with few reports published mainly on copper (Cu) (Pacheco et al, 1986) and boron (B) (Tohiruddin et al, 2010;Vié gas et al, 2019). Matos et al, 2016 conduced a nutritional diagnosis in commercial oil palm plots in northeastern Pará State, Brazil, and indicated the Mn and Zn are the most deficient micronutrients in oil palm trees. Although some studies have evaluated micronutrient concentrations in oil palm trees in Pará State (Matos et al, 2017;Matos et al, 2019;Vié gas et al, 2020), they have not investigated the effect of fertilization on micronutrient concentrations.…”

“…In Pará State, the analysis of the soil, plant age, and crop yield recommends the use of macronutrients for the fertilization of oil palm plantations. For micronutrients, only boron is recommended (Franzini et al, 2020), although there is a suggestion of micronutrients application in the crop nutritional management plan (Matos et al, 2016).…”

Spatial Variability in Leaf Analysis and Productivity of Fertirrigated Açaí

“…There are still no adequate nutritional ranges published for açaí, however average macronutrient contents showed values within the ranges considered adequate by Brasil et al (2008) for adult açaí trees and close to the ideal ranges for economically important species of the Arecaeae family, such as the oil palm Elaeis guineensis Jacq. (Matos et al, 2016) and peach palm Bactris gasipaes Kunth (Fernandes et al, 2013). Soil fertility parameter averages showed good levels except for boron, which was considered low according to the soil interpretation ranges of Ribeiro et al (1999).…”