Liming and macronutrient on early growth of Eucalyptus benthamii

Diego Pereira Da Rosa,Marcio Carlos Navroski,Pedro Henrique Tavares Da Fonseca,Jaiton Jaime Das Neves Silva,Mariane De Oliveira Pereira,Eleandro José Brun

doi:10.1590/0103-8478cr20200549

Abstract

ABSTRACT: Macronutrient suppression is one way to identify which chemical elements is the most important in the early development of seedlings of forest species. This study evaluated the initial growth of Eucalyptus benthamii seedlings through morphological and physiological variables, submitted to doses of N, P and K, and liming. The experimental design to install the experiment was completely randomized, with a 2x9 factorial scheme, in which levels of factor “A” referred to absence and presence of liming and levels of factor “B”, to the different treatments of NPK. Morphological variables of SD (stem diameter) and H (height) and the physiological variables of A (photosynthesis), E (transpiration), gs (stomatal conductance), Ci/Ca (relationship between intercellular and atmospheric CO2 concentration) and WUE (water use efficiency) were measured. For morphological variables, the absence of N directly affected the means and there was a direct relationship between increase of the dose and increase of SD and H. There was a positive relationship of P mainly in relation to shoot dry matter content (SDMC) and root dry matter content (RDMC). For the physiological variables, there was no direct response with the doses of N or P, with K being the element that most influenced the variables, especially when limestone was applied, resulting in higher averages for photosynthesis, transpiration and stomatal conductance. With the purpose of meeting the morphological and physiological demands, the recommendation for cultivation of Eucalyptus benthamii under the conditions of this study is the doses 150-200-150, without liming application.

Highlights

Eucalyptus ranks among the most economically important trees globally (BAYLE et al, 2019)
Morphological variables For the SD variable, the results comparing the factors with and without liming had a statistical difference in the dose 300-200-150 (N-P-K), presenting a mean for the factor without liming 26% higher when compared to the factor with liming (Table 1)
The absence of N negatively affected the means of the morphological variables and there was a direct relationship between increasing the dose and increasing the means

Summary

Introduction

Eucalyptus ranks among the most economically important trees globally (BAYLE et al, 2019). They exhibit traits, such as fast growth (LORENTZ & MINOGUE, 2015) and high water and light use efficiency (MAIER et al, 2017), that contribute to their candidacy as an excellent biofuel crop (GONZALEZ et al, 2018). For the species to manifest its productive potential, it is necessary that the essential elements are available in the soil for absorption, given that the species originally occurs in fertile soils. In this sense, considering the low fertility of most Brazilian soils, liming and fertilization practices are essential to provide nutrients that are not in satisfactory concentrations to meet the demands of plants in the reforestation areas (SILVA et al, 2012)

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Conclusion