Pequi bark biochar as a substrate component for the production of Eucalyptus urophylla S. T. seedlings

Abstract

The use of substrates using or biochar as a component is a viable alternative in the production of forest seedlings, due to improvements in physical-chemical characteristics. In view of the above, the objective of this study was to evaluate the effect of particle size and the proportion of biochar bark from cariacar brasiliense on the production of Eucalyptus urophylla seedlings. The biochar was used in four particle sizes (> 0.5; 0.5-1.0; 1.0-2.0; 2.0-4.0 mm), mixed with the commercial substrate @bioplant (Sphagnum peat, coconut fiber, rice husks, pine husks and vermiculite) in five proportions: 0, 25, 50, 75%, 100% (v / v). Biodegradable as physical properties, particle density, bulk density and porosity of the tested substrates. The physiological development of the changes, on the other hand, was analyzed using the variables: germination percentage, emergence speed index, height, neck diameter, height / neck diameter ratio, articulated root length, dry root mass and dry mass for 120 days, correlating with the technical and chemical characteristics of the biochar used. The addition of biochar in smaller proportions (<25%) to the commercial substrate, gives the substrate improvements in the physical-chemical attributes, such as the increase in porosity. We conclude that the best physiological results for the species under study were used using biochar grain sizes between 1 and 4 mm regardless of the proportion and applied biochar.