Saturação de bases em solo do cerrado para produção de mudas de pequizeiro e baruzeiro

Abstract

The pequiary (Caryocar brasiliense) and the baruzeiro (Dipteryx alata) are native fruits of the Cerrado, being exploited, exclusively, by means of extractivism. These species are of great economic and social importance, which justifies domestication. However, there is a lack of information on the nutritional requirements of these species, especially on the formation of seedlings. The objective of this work was to evaluate the growth and quality of C. brasiliense and D. alata seedlings due to soil base saturation. The experiment was carried out in pots with dystrophic and alico cerrado sensu stricto soil in a greenhouse at the Institute of Agrarian Sciences of the Federal University of Minas Gerais, from October 2015 to July 2016. Separate experiments were set up for each species, with a completely randomized block design and, as treatments, five levels of base saturation (V%), obtained by the application of commercial correction: 10 (natural saturation), 25, 40, 55 and 75% with five replicates, two pots per plot and two plants per pot. At the end of the experiments, when the plants of the two species were already present in the seedling stage, 5 and 7.5 months, respectively, for the pequi and baru tree, the following biometric characteristics and their relationships were evaluated: plant height (ALT , In cm), the collecting diameter (CD, in mm); The number of leaflets and leaves (NF), fresh shoot mass (FSM, grass plant-1); fresh root mass (FRM, grass plant-1); dry shoot mass (DSM, grass plant-1); root dry mass (RDM, grass plant-1); total dry mass (TDM, plant grass-1), obtained by adding DSM and RDM; Ratio of shoot dry mass and dry mass of the root (RSDMDMR); Ratio of shoot height and shoot diameter (RSD); Dickson quality index (DQI) and the amount of macro and micronutrients in the shoot. The data were submitted to analysis of variance and, when significant, regression equations were adjusted, relating the morphological attributes evaluated and the amount of macro and micronutrients (B, Cu, Fe, Mn and Zn) in the aerial part, with the different Levels of saturation by bases by Student's t-test at the level of 1 and 5% of probability of error. The liming, in general, interfered only with the height of the plants, their relationship with the collecting diameter and the accumulation of nutrients of the shoot in pequi tree seedlings. On the other hand, the increase in the base saturation between 40 and 50%, in general, increased the diameter, mass, quality and quantity of macronutrients in the seedlings. The decreasing order of nutrient accumulation, in the aerial part for saplings and baruzeiro, respectively, was: N> K> Ca> S> Mg> P> Fe> Mn> BZn> Cu and N> K> PMgS> Fe> Mn> Zn> B> Cu. Keywords: Liming. Caryocar brasiliense. Dipteryx alata. Macronutrients and micronutrients. Base Saturation.