Norms establishment of the Diagnosis and Recommendation Integrated System (DRIS) for nutritional diagnosis of sugarcane

Abstract

-The objectives of this study were to establish DRIS norms for sugarcane crop, to compare mean yield, foliar nutrient contents and variance of nutrient ratios of low-and high-yielding groups and to compare mean values of nutrient ratios selected as the DRIS norms of low-and high-yielding groups. Leaf samples (analyzed for N, P, K, Ca, Mg, S, Cu, Mn and Zn contents) and respective yields were collected in 126 commercial sugarcane fields in Rio de Janeiro State, Brazil and used to establish DRIS norms for sugarcane. Nearly all nutrient ratios selected as DRIS norms (77.8%) showed statistical differences between mean values of the low-and high-yielding groups. These different nutritional balances between the low-and high-yielding groups indicate that the DRIS norms developed in this paper are reliable. The DRIS norms for micronutrients with high S² l /S² h ratio and low coefficient of variation found can provide more security to evaluate the micronutrient status of sugarcane.Index terms: Saccharum officinarum, foliar nutrient content, plant analysis, nutritional status, productivity. Estabelecimento de normas do Sistema Integrado de Diagnose e Recomendação (DRIS) para a diagnose nutricional da cana-de-açúcarResumo -Os objetivos deste trabalho foram estabelecer normas DRIS para a cultura da cana-de-açúcar, comparar médias de produtividade, médias de teores foliares de nutrientes e variâncias das razões entre nutrientes dos grupos de baixa e alta produtividade e comparar valores médios das razões selecionadas como normas DRIS dos grupos de baixa e alta produtividade. Amostras foliares (analisadas quanto a N, P, K, Ca, Mg, S, Cu, Mn e Zn) e respectivas produtividades foram coletadas em 126 lavouras comerciais, em Campos dos Goytacazes, RJ, e usadas para estabelecer as normas DRIS para a cana-de-açúcar. As médias de produtividade e de teores foliares não foram similares entre os grupos de baixa e alta produtividade. As razões entre variâncias dos grupos de alta e baixa produtividade foram diferentes. A maioria das razões entre nutrientes selecionadas como normas DRIS apresentaram médias estatisticamente diferentes entre os grupos de baixa e alta produtividade. Estes diferentes equilíbrios nutricionais entre os grupos de alta e baixa produtividade indicam que as normas DRIS estabelecidas neste trabalho são confiáveis. As normas DRIS obtidas com valores altos de razão entre variâncias dos grupos de alta e baixa produtividade e baixos coeficientes de variação oferecem maior segurança para avaliar o estado nutricional da cana-de-açúcar em relação aos micronutrientes.Termos para indexação: Saccharum officinarum, teor foliar de nutriente, análise vegetal, estado nutricional, produtividade.

DRIS norms validation for sugarcane crop

“…The relationship between DRIS indices and foliar nutrient concentrations were evaluated with the sugarcane foliar nutrient concentrations from the database built by Reis Junior & Monnerat (2003). DRIS indices for all database were established with DRIS norms developed by Reis Junior & Monnerat (2003), according to Beaufils (1973), through a sheet developed in MS-Excel 2000 for IBM-PC.…”

“…DRIS indices for all database were established with DRIS norms developed by Reis Junior & Monnerat (2003), according to Beaufils (1973), through a sheet developed in MS-Excel 2000 for IBM-PC. The sensitivity coefficient (k) used in DRIS calculations was equal to ten.…”

“…Field experiments were used to validate sugarcane DRIS norms (Reis Junior & Monnerat, 2003). Leaves from three sugarcane ratoon experiments, conducted at Bambuzal (field 1), Duas Barras II (field 2) and Fazendinha (field 3), in the State of Rio de Janeiro, Brazil, were sampled and analyzed during the 1996/97 season.…”

“…Leaves from three sugarcane ratoon experiments, conducted at Bambuzal (field 1), Duas Barras II (field 2) and Fazendinha (field 3), in the State of Rio de Janeiro, Brazil, were sampled and analyzed during the 1996/97 season. The method of sampling and chemical tissue analysis were described in Reis Junior & Monnerat (2003). DRIS indices were calculated with the results of these foliar analyses.…”

“…Leaf samples were collected in each plot of the experiment, four months after plant sprouting, analyzed as described by Reis Junior & Monnerat (2003), and then a new diagnosis was performed with DRIS.…”