Crescimento e nutrição de louro pardo (Cordia trichotoma (Vell.) Arrab. Ex Steud) em sistema silvipastoril

Abstract

This study aims to evaluate the growth and nutritional of Louro Pardo (Cordia trichotoma (Vell.) Arrab. Ex Steud.) in silvopastoral system, according to different levels of fertilization, in combined cultivation with the grass Panicum maximum cv. Aruana. The study area belongs to the UNEPE (Education and Research Unit) of caprine sector of the Federal Technological University of Paraná, in Dois Vizinhos. The Louro Pardo was planted in September 2013 in an area of 2160 m². The planting was organized in four double lines for the tree species, in an interval of 10m using a spacing of 2 m x 1,5 m in the lines. For the growth assessment, it was measured the stem diameter (Ds), height (H) and tree crown area (Ac). The treatments for Louropardo were defined using four levels of fertilization, which are the following: no fertilization (T1), the recommended by the soil analysis (T2), the double (T3) and the triple (T4) of the recommended. To evaluate this study, it was measured the plants’ height, stem diameter and two equidistant tree crown diameters, as well as qualitative evaluations of vitality. About the specie’s nutrition study, the soil samples were collected at different depths: 0-10cm; 10 - 20cm; 20 - 40cm and 40 – 60cm in the full area. It was collected leaf samples of branches located in the upper third part of the tree canopy, using compound samples, collecting 12 mature and full leaves per tree and considering 4 trees in each treatment, one in each block, resulting in 16 samples. The soil and tissues samples were analyzed at the Laboratory of Soil Analysis of UTFPR. The results allowed to conclude that the T4 was highlighted in all of the growth parameters evaluated, which showed a difference of about 1 meter higher than T1. In T4, the high vitality was 100% in the plants with 24 months old. The nitrogen concentration found in the leaves was considered high in relation to the content of the leaves of Eucalyptus sp. About the nutrients average, in all soil depths, the level of N and P was higher just on T4 when compared to the other treatments. In the 24 months assessment of stem diameter, the T4 had an average of 100% higher than T1. For the tree crown evaluation done with 24 months, T4 showed an average of 41% more than T1.