Qualidade de mudas de copaifera langsdorffii cultivadas em substratos alternativos em função da adubação complementar, fontes e métodos de aplicação de ácidos húmicos

Abstract

Slow initial growth in native forest species is one of the main problems faced in the seedling production sector. In this regard, it is important to define protocols and strategies that favor the production of quality seedlings that present high rates of initial growth and survival after planting in a shorter time and conditions accessible to small and medium-sized rural producers, As this is the most interested public in this type of input. This work aimed to evaluate the production of Copaifera langsdorffi seedlings as a function of complementary mineral fertilization in different organic substrates and sources and methods of humic acid application. The experiment was divided into two phases, the first one being developed at the research nursery in the production of forest seedlings at the Federal University of Tocantins - UFT, Campus Gurupi. The first experiment was installed in a randomized complete block design with a 50% luminosity retention, in a 2x12 factorial scheme, with 10 repetitions. In the composition of the substrates was used Worm Humus (HM), Pre-carbonized Rice Peel (CAPc), Commercial Substrate (SC) and Subsoil Land (TS) with or without additional fertilization. The substrate composed of Worm Humus (50%) and subsoil soil (50%) in the absence of fertilization provides an improvement in the morphology of the seedlings as dry shoot mass, dry mass of the roots and the highest quality index of seedlings. Substrates with 75% commercial substance and 25% subsoil and 100% commercial substrate do not require fertility supplementation with fertilization to promote improvement in seed quality index. Substrate composition of 50% earthworm humus and 50% subsoil soil without the use of fertilization provided a better molt quality index. The second experiment was implemented and developed in nursery for the production of forest shrubs under cover of the sombrite type with 50% retention of luminosity, located in the municipality of Dianópolis state of Tocantins. The experimental design was completely randomized, with five replications. The treatments were based on methods of application by the sources of humic substances, the commercial product - Fertiactyl ® and humic acids obtained from alternative organic compounds (alternative humic acid - AHA). Saplings that do not receive humic acid application present a greater increase in root length, but lower dry root mass when compared to seedlings receiving humic substances. The highest quality index of seedlings occurs when commercial humic acid is applied via foliar, while the lowest index occurs when it does not use humic substances. Thus, the use of organic compounds, either in the substrate composition and / or the application of humic acids promotes improvement in the development of Copaifera langsdorffi seedlings.