Diagnose da composição nutricional de povoamentos clonais de eucalipto pelo método CND
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2022-12-06
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Universidade Federal dos Vales do Jequitinhonha e Mucuri
Resumo
O monitoramento nutricional em plantios de eucalipto por meio da análise foliar subsidia ajustes no manejo nutricional para manter e/ou alcançar maiores produtividades. Dentre os métodos de interpretação da análise foliar destaca-se a Diagnose da Composição Nutricional (CND). O CND é uma expansão multivariada dos métodos univariados e bivariados que pode resultar em diagnósticos mais precisos e expressar o grau de equilíbrio nutricional da cultura, por considerar a interação entre todos os nutrientes. O objetivo deste estudo foi avaliar a eficiência do método CND na diagnose nutricional de plantios clonais de eucalipto. O banco de dados foi composto de teores foliares de macro e micronutrientes e crescimento de plantios de eucalipto, compreendidos por diferentes genótipos e idades (de 0,4 a 72 meses). Estes, foram coletados de diversas empresas e situados em várias localidades do país. A população de referência foi obtida com base na abordagem da linha de fronteira superior do relacionamento entre o crescimento em altura em função da idade. As normas CND foram obtidas a partir desta população. Posteriormente, foram obtidos os índices CND e os nutrientes foram ordenados quanto ao grau de limitação nutricional de acordo com o potencial de resposta à adubação (PRA). Os índices CND também foram relacionados com o crescimento relativo em altura (CRH) e com o crescimento relativo em volume (CRV). Posteriormente, a região de fronteira superior destes relacionamentos foi utilizada para gerar as curvas de resposta potencial nutrientes específicas (CRPNE). Estas, foram ajustadas através de dois modelos: o polinomial de 2° grau e a regressão duplo linear com resposta platô (RDLP) a fim de comparar quais dos modelos se ajustariam melhor aos dados. A partir das CRPNE foram obtidas as faixas de suficiência (FSU) para os índices CND, utilizando tanto as equações ajustadas pelo modelo polinomial de 2° grau quanto as ajustadas pela RDLP. A diagnose nutricional dos plantios de eucalipto também foi realizada considerando as FSU. O estabelecimento de normas CND utilizando a população de alta produtividade estabelecida pela linha de fronteira demonstrou ser apropriada para a maioria dos nutrientes. As normas CND obtidas para macro e micronutriente, foram precisas para todos os nutrientes, exceto para P, Mn e S. A sequência de limitação por falta dos nutrientes dada pelo PRA foi Cu > Mg = S > Fe = Mn > Ca > Zn = B > N > P = K. As CRPNE foram explicativas, sendo que aquelas obtidas pela RDLP se ajustaram melhor ao relacionamento entre os índices CND e o CRH e o CRV. As FSU obtidas para o CND são assimétricas quanto aos seus limites e apresentaram intervalos bem amplos. Estas, foram adequadas para avaliar o status nutricional de povoamentos clonais de eucalipto e demonstraram que a maioria dos talhões avaliados enquadraram-se na classe normal. Palavras chave: Análise foliar, Eucalyptus, Nutrição florestal, Silvicultura.
Nutritional monitoring in eucalyptus plantations using leaf analysis is an important tool for adjustments in nutritional management in order to maintain and/or achieve greater yields. The Compositional Nutrient Diagnosis (CND) is one of the main. methods for interpretation of leaf analysis. The CND is a multivariate extension of univariate and bivariate methods that can result in more accurate diagnoses, besides providing the degree of nutritional balance in the plantation, since it considers the interaction between all the nutrients. The objective of this study was to evaluate the efficiency of the CND method for the nutritional diagnosis of eucalyptus in clonal plantations. The data base was composed of foliar levels of macro and micronutrients and growth indicators for different genotypes and ages (from 0.4 to 72 months) of eucalyptus plantations. Such data were collected from several companies and locatedacross multiple locations in Brazil. The reference population was obtained based on the upper border line approach of the relationship between increase in height as a function of age. CND norms were obtained from this population. Further, the CND indices were estimated and the nutrients were ordered according to the degree of nutritional limitation according to the potential response to fertilization. CND indices were also related to relative increase in height (CRH) and relative increase in volume (CRV). As the next step, the upper border region of these relations was used to generate potential nutrient-specific potential response curves (CRPNE). The CRPNE were adjusted using two models: the 2nd degree polynomial and the double linear regression with plateau response (RDLP) in order to compare which of the models would best fit the data. From the CRPNE, the sufficiency ranges (FSU) for the CND indices were obtained, using both the equations adjusted by the 2nd degree polynomial model and those adjusted by the RDLP. The nutritional diagnosis of eucalyptus plantations were also carried out considering the FSU. Setting CND norms using the greater-yield population across the boundary line has been shown to be appropriate for most nutrients. The CND norms obtained for macro and micronutrients were accurate for all nutrients, except for P, Mn and S. According to the PRA, the nutrients most limiting the eucalyptus yield was Cu > Mg = S > Fe = Mn > Ca > Zn = B > N > P = K, respectively. The CRPNE were explanatory, and those obtained by the RDLP fitted better to the relation among the CND indices and the CRH and CRV. The FSU obtained for the CND are asymmetric in terms of their limits and showed spacious intervals. These were suitable for assessing the nutritional status of eucalyptus clonal plantations and demonstrated that most of the evaluated plots fits in the normal class. Keywords: Leaf analysis, Eucalyptus, Forest nutrition, Silviculture.
Nutritional monitoring in eucalyptus plantations using leaf analysis is an important tool for adjustments in nutritional management in order to maintain and/or achieve greater yields. The Compositional Nutrient Diagnosis (CND) is one of the main. methods for interpretation of leaf analysis. The CND is a multivariate extension of univariate and bivariate methods that can result in more accurate diagnoses, besides providing the degree of nutritional balance in the plantation, since it considers the interaction between all the nutrients. The objective of this study was to evaluate the efficiency of the CND method for the nutritional diagnosis of eucalyptus in clonal plantations. The data base was composed of foliar levels of macro and micronutrients and growth indicators for different genotypes and ages (from 0.4 to 72 months) of eucalyptus plantations. Such data were collected from several companies and locatedacross multiple locations in Brazil. The reference population was obtained based on the upper border line approach of the relationship between increase in height as a function of age. CND norms were obtained from this population. Further, the CND indices were estimated and the nutrients were ordered according to the degree of nutritional limitation according to the potential response to fertilization. CND indices were also related to relative increase in height (CRH) and relative increase in volume (CRV). As the next step, the upper border region of these relations was used to generate potential nutrient-specific potential response curves (CRPNE). The CRPNE were adjusted using two models: the 2nd degree polynomial and the double linear regression with plateau response (RDLP) in order to compare which of the models would best fit the data. From the CRPNE, the sufficiency ranges (FSU) for the CND indices were obtained, using both the equations adjusted by the 2nd degree polynomial model and those adjusted by the RDLP. The nutritional diagnosis of eucalyptus plantations were also carried out considering the FSU. Setting CND norms using the greater-yield population across the boundary line has been shown to be appropriate for most nutrients. The CND norms obtained for macro and micronutrients were accurate for all nutrients, except for P, Mn and S. According to the PRA, the nutrients most limiting the eucalyptus yield was Cu > Mg = S > Fe = Mn > Ca > Zn = B > N > P = K, respectively. The CRPNE were explanatory, and those obtained by the RDLP fitted better to the relation among the CND indices and the CRH and CRV. The FSU obtained for the CND are asymmetric in terms of their limits and showed spacious intervals. These were suitable for assessing the nutritional status of eucalyptus clonal plantations and demonstrated that most of the evaluated plots fits in the normal class. Keywords: Leaf analysis, Eucalyptus, Forest nutrition, Silviculture.
Descrição
Palavras-chave
Análise foliar, Eucalyptus, Nutrição florestal, Silvicultura
Citação
Silva, Laís Graziele. Diagnose da composição nutricional de povoamentos clonais de eucalipto pelo método CND. 2022. 99 f. Tese (Doutorado em Ciência Florestal) - Universidade Federal dos Vales do
Jequitinhonha e Mucuri, Diamantina,. 2022.