Nutrient use efficiency in interspecific hybrids of eucalypt

Abstract

-The aim of this work was to evaluate nutrient use efficiency in interspecific hybrids of eucalypt, as an aid in the development of forest breeding programs for areas with limited nutrients. To do this, five clones were evaluated at 2.25 years of age from hybrids resulting from crosses of Eucalyptus grandis x E. urophylla (C1, C2, C3, C4 and C5). The experimental design was of randomised blocks, with single-tree plots and 35 replications. For the study, four trees of average performance were cut down (replications) from each treatment (clone); the biomass, and content and efficiency of use of N, P, K, Ca and Mg were determined in the wood, bark, leaves and branches. The data were submitted to analysis of variance and the F-test, and the means compared by Tukey's test at 5% probability. It was found that the average for biomass allocation was greater (66.2%) for the wood, followed by the branches (13.2%), leaves (11.0%) and bark (9.6%). The C2 and C5 clones stood out as the most efficient in the use of P, Ca and Mg in the wood. The use of genotypes which are efficient in the use of nutrients is essential to the sustainability of forest ecosystems, reducing nutrient export in proportion to the biomass produced. Also, the recommendation of genotypes which are efficient in the use of nutrients for sites of poor soil fertility can optimise productivity in these locations.

Exploring the factors affecting carbon and nutrient concentrations in tree biomass components in natural forests, forest plantations and short rotation forestry

“…On the one hand, comparing the data of this study for clones and seedlings, the NAI, or cost per unit of wood yield in terms of two of the most limiting nutrients in the area (P and Ca) may therefore be reduced considerably (45 and 35% less, respectively) by using genetically improved material. The selection of genotypes with more efficiency in the use of nutrients has been applied for hybrid eucalypts in Brazil (Rosim et al 2016). In a study carried out in Congo, Safou-Matondo et al (2005) demonstrated the superiority of several clones of Eucalyptus urophylla regarding P (+ 72%) and Ca (+ 43 to + 59%) assimilation index.…”

Nutritional Efficiency of Eucalyptus Clones Under Water Stress

“…During restrictions in resource supply, these processes become critical. Higher AE and UE resulted in higher biomass yield (Rosim et al, 2016), allowing maintenance of productivity, mainly on nutrient-poor soils. Consequently, genotypes with greater capacity of nutrient absorption and/or use are more desirable (Godoy and Rosado, 2011), because, in addition to a better exploitation of the fertilized nutrients, smaller amounts of nutrients are required for growth (increased efficiency).…”

Eficiência De Utilização De Nutrientes Pelo Eucalipto Em Sistema Agrossilvipastoril

“…Na literatura, diversos são os estudos que avaliam a EUN para selecionar espécies ou clones na área florestal (DICK et al, 2017;SILVA, 2017;ROSIM et al, 2016;MEDEIROS et al, 2016;GUIMARÃES et al, 2015;FARIA et al, 2008), especialmente para o Eucalyptus urograndis, clone H13 em consórcio de ILPF (CARVALHO, 2017), compreendendo especialmente, os compartimentos da biomassa exportados na colheita (tronco e casca).…”