Avaliação química de compostos orgânicos como potenciais condicionadores de solos e substratos de plantas

Abstract

With the increase in population comes the increase in the consumption of goods and services and, consequently, the generation of waste from their production and consumption. In large Brazilian cities, these residues are characterized by containing a high amount of organic matter. Much of this waste ends up being improperly disposed of in landfills, wasting its recycling potential. The objective of this work was to evaluate the chemical quality of five different organic residues potentially usable in agriculture and the influence of organic substrates on the initial development of Paricá (Schizolobium amazonicum Huberr ex Ducke). The work consisted of two studies, the first refers to the chemical characterization of different organic materials, and the second refers to the use of organic substrates and plant growth. The analyzes were carried out in the soil analysis laboratory of EMBRAPA - Eastern Amazon, to obtain the total levels of macro and micronutrients present in the residues. Waste from semi-decomposed hose pruning (PD), carbonized sludge (LC), boiler ash (CC), composed of waste from the composting process of organic waste from the Centro de Abastecimento de Belém (CEASA) (CO-1 ) and fish feed composting product (CO-2). To evaluate the initial development of paricá, an experiment was conducted in a greenhouse at the Instituto de Ciências Agrárias – UFRA from March to July 2022. The experimental design was completely randomized, consisting of 5 treatments and four replications. In the composition of the substrate, different proportions of vermiculite (VE) and organic compound (CO-1) from the process of composting organic waste from the Centro de Abastecimento de Belém (CEASA) were used. The treatments were: T1 - Vermiculite (100%); T2 - Vermiculite (50%) + Organic Compound-1 (50%); T3 - Vermiculite (30%) + Organic Compound-1 (70%); T4 - Vermiculite (10%) + Organic Compound-1 (90%); and T5 - Organic Compound-1 (100%). The species used for the study was the Paricá (Schizolobium amazonicum Huberr ex Ducke). At 27, 60 and 94 days after sowing, shoot height (H), stem diameter (DC), shoot dry mass (MSPA), root (MSR) and total (MST) were evaluated. With the data in hand, the relationships between shoot height and stem diameter (H/DC) and Dickson's quality index (DQI) were calculated. The results were submitted to analysis of variance (ANOVA) and the averages to the Tukey test considering a level of 5% of probability. With the results obtained, in relation to the study of chemical characterization of the organic residues, the carbonized sludge and boiler ash, stood out from the other organic materials for presenting a high concentration of the analyzed nutrients. The carbonized sludge had the highest levels of P, Na, Fe, Zn and Cu, while the boiler ash had the highest levels of N, K, Ca, Mg and Mn. The organic compound-1 was the one that presented the lowest contents of the studied nutrients. The results for the paricá growth experiment show that the use of organic compound-1 positively influenced the growth and development of Schizolobium amazonicum Huberr ex Ducke seedlings, with emphasis on T5 (100% organic substrate-1). Thus, the residues studied have favorable chemical characteristics for their use as soil conditioners and source of nutrients, as well as their use in the composition of substrates for seedling production. The treatment of organic waste and its use in the soil minimizes the effects of pollution, being a safe and environmentally sustainable practice.