Data/hora: 16/06/2024 15:40:50

Provedor de dados: | Revista Brasileira de Ciência do Solo
País: | Brazil
Título: | LEAF TOTAL NITROGEN CONCENTRATION AS AN INDICATOR OF NITROGEN STATUS FOR PLANTLETS AND YOUNG PLANTS OF EUCALYPTUS CLONES
Autores: | Ferreira,Eric Victor de Oliveira; Novais,Roberto Ferreira; Médice,Bruna Maximiano; Barros,Nairam Félix de; Silva,Ivo Ribeiro.
Data: | 2015-08-01
Ano: | 2015
Palavras-chave: | Eucalyptus; N/P ratio; Nutritional diagnosis; Plant analysis; Soil fertility evaluation; Chlorophyll meter.
Resumo: | The use of leaf total nitrogen concentration as an indicator for nutritional diagnosis has some limitations. The objective of this study was to determine the reliability of total N concentration as an indicator of N status for eucalyptus clones, and to compare it with alternative indicators. A greenhouse experiment was carried out in a randomized complete block design in a 2 × 6 factorial arrangement with plantlets of two eucalyptus clones (140 days old) and six levels of N in the nutrient solution. In addition, a field experiment was carried out in a completely randomized design in a 2 × 2 × 2 × 3 factorial arrangement, consisting of two seasons, two regions, two young clones (approximately two years old), and three positions of crown leaf sampling. The field areas (regions) had contrasting soil physical and chemical properties, and their soil contents for total N, NH+4-N, and NO−3-N were determined in five soil layers, up to a depth of 1.0 m. We evaluated the following indicators of plant N status in roots and leaves: contents of total N, NH+4-N, NO−3-N, and chlorophyll; N/P ratio; and chlorophyll meter readings on the leaves. Ammonium (root) and NO−3-N (root and leaf) efficiently predicted N requirements for eucalyptus plantlets in the greenhouse. Similarly, leaf N/P, chlorophyll values, and chlorophyll meter readings provided good results in the greenhouse. However, leaf N/P did not reflect the soil N status, and the use of the chlorophyll meter could not be generalized for different genotypes. Leaf total N concentration is not an ideal indicator, but it and the chlorophyll levels best represent the soil N status for young eucalyptus clones under field conditions.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000401127
Editor: | Sociedade Brasileira de Ciência do Solo
Relação: | 10.1590/01000683rbcs20140689
Formato: | text/html
Fonte: | Revista Brasileira de Ciência do Solo  v.39 n.4 2015
Fonte: | info:eu-repo/semantics/openAccess