http://repositorio.ufc.br/handle/riufc/108 2026-04-07T13:17:33Z http://repositorio.ufc.br/handle/riufc/85586 Título: Digestato de reator anaeróbio oriundo de resíduos alimentares como fonte de nutrientes Autor(es): Sousa, Bruno Eduardo Lopes Abstract: The improper disposal of food waste contributes to greenhouse gas emissions and the contamination of soil and water. One alternative to this issue is the treatment of such waste through anaerobic digestion, a process that generates biogas and a nutrient-rich by-product known as digestate, which has potential use as an organic fertilizer in agriculture. This project aims to evaluate the potential of digestate as a fertilizer for maize plants, seeking to reduce dependence on mineral fertilizers and improve soil properties. The hypothesis is that digestate derived from food waste can provide results comparable to mineral fertilization in maize cultivation. To test this hypothesis, a greenhouse experiment will be conducted at the Federal University of Ceará, using soil samples and digestate produced from food waste. The experimental design will be completely randomized, with six treatments and four replicates:T1: Control (no fertilizer), T2: 100% mineral fertilizer, T3: 75% mineral fertilizer + 25% liquid digestate, T4: 50% mineral fertilizer + 50% liquid digestate, T5: 25% mineral fertilizer + 75% liquid digestate, T6: 100% liquid digestate. Fertilizer dosages were defined based on the chemical analysis of the digestate, taking into account the availability of nitrogen, phosphorus, and potassium, and following agronomic recommendations for maize. The mineral fertilizers used were urea, triple superphosphate, and potassium chloride. Plant biometric parameters were evaluated, including height, number of leaves, and stem diameter. Dry and fresh shoot biomass were analyzed, as well as the chemical composition of macro- and micronutrients in the plants. Soil analyses included: pH, electrical conductivity (EC), phosphorus, calcium, magnesium, potassium, sodium, copper, iron, manganese, zinc, sum of bases, cation exchange capacity (CEC), exchangeable sodium percentage (ESP), sodium adsorption ratio (SAR), and potential acidity. Data were analyzed using multivariate techniques, including principal component analysis and ANOVA. Treatment means were compared using mean comparison tests, with analyses performed in SAS (Statistical Analysis System, 1995), considering a significance level of 5%. The results showed that treatments T2, T3, T4, and T5 promoted higher means for plant biometric variables, nutrient accumulation in plant biomass, and soil fertility. Treatment T4 (50% mineral fertilizer + 50% digestate) stood out by significantly increasing plant height (128.5 cm), representing an 83.57% increase compared to the control; it also promoted the largest stem diameter (21.72 mm), with a 125.78% increase compared to the control, and the highest number of leaves, with a 33.33% increase over the control. The combination of digestate with mineral fertilizers enhanced the availability of macro- and micronutrients, increasing their concentration in the soil without causing harmful sodium accumulation. Although treatment T6 (100% digestate) presented lower results compared to those with mineral fertilizer blends, it performed better than the control, suggesting its potential as a standalone fertilizer, albeit with reduced productivity. Partial replacement of mineral fertilizers with liquid digestate—especially in the 50% mineral fertilizer + 50% digestate ratio—proved effective for maize fertilization, providing agronomic results equivalent to or superior to conventional fertilization and offering environmental benefits by utilizing food waste. Tipo: Dissertação 2025-01-01T00:00:00Z http://repositorio.ufc.br/handle/riufc/85323 Título: Calagem e o crescimento inicial de pitaia vermelha (Hylocereus polyrhizus) propagada por sementes Autor(es): Oliveira, Iana Maria de Souza Abstract: The red pitaya (Hylocereus polyrhizus) is an epiphyte cactacea that has aroused great interest in the years due to its exotic appearance, peculiar flavor and nutraceutical qualities, in addition to the very attractive market price for rural producers. However, there are still few studies on the management carried out in the culture of pitaya. Liming is a relevant management, which should be studied since most of the Brazilian soils present an acid reaction, compromising the production of most crops. Thus, the objective of this work was to study the effects of liming on the chemical characteristics of the soil, on the morphological processes and nutritional status of red pitaya, propagated from seeds. The experiment was conducted in a protected environment and in the field, with the pots distributed according to the statistical design in randomized blocks, with five treatments (doses of limestone 0; 0.6; 1.2; 1.8; 2.5 t ha -1) and four repetitions. Each plot of the experiment consisted of two pots, for a total of 40 experimental units, one plant per pot. Throughout the period, experiments were carried out when evaluating the vegetative growth of the studied species in relation to biometric parameters. The study of contents and accumulation of nutrients in the aerial part of the plant was also carried out at the end of the experiment. The data were prepared for analysis of variance by the F test and regression analysis. Liming to increase pH and base saturation, as well as reducing aluminum saturation and adjusting the availability of nutrients. PH values between 5.5 and 6.0 and base saturation (V%) between 40 and 50% are considered adequate for the good initial development of the red pitaya. The biometric variables cladode diameter (DC), cladode thickness (EC), length of the root system (CSR), dry mass of the cladode (MSC) and dry mass of the root system (MSSR), increased positively, maximum values between the doses 1.0 t ha-1 and 1.5 t ha-1, this being the ideal range recommended to achieve the greatest growth of the plants. As for the nutrient content in the aerial part, the levels of N, P and Mg increased and Zn and Mn decreased in the plants, finding the following bands that feed the largest vegetative increments: phosphorus 9.4 - 10.0 g kg-1; magnesium 5.3 - 6.0 g kg-1; nitrogen 5.3 - 6.0 g kg-1; zinc 187.0 - 218.2 mg kg-1; manganese 162.0 - 177.0 mg kg-1. Liming contributed to the accumulation of macronutrients N, P, K, Ca and Mg and micronutrients Cu, Mn and Zn in the cladodes. Tipo: Dissertação 2021-01-01T00:00:00Z http://repositorio.ufc.br/handle/riufc/85321 Título: Como a carcinicultura afeta a dinâmica de fósforo em solos de manguezais? Autor(es): Silva, Lorena Maria Gomes Abstract: Mangroves are coastal ecosystems of great ecological and socioeconomic importance, recognized for their high capacity to store carbon and nutrients. However, these environments have been progressively degraded by anthropogenic actions, mainly by shrimp farming, which, in addition to converting extensive areas into nurseries, releases effluents rich in nutrients such as phosphorus (P) and nitrogen (N), which contribute to the process of eutrophication and ecological imbalance. The disposal of these effluents alters the biogeochemical dynamics of the soil, mainly the interactions with organic matter (OM) fractions, and may cause important changes in P dynamics. The objective of this study was to evaluate how effluents from shrimp farming affect P dynamics in semiarid mangrove soils, focusing on the relationship between P and organic matter fractions and enzymatic activity (alkaline and acid phosphatases), which are important for understanding microbial activity and P cycles in the soil. Thus, paired soil samples were collected from impacted and unimpacted areas in three sectors of the Acaraú River estuary (Ceará, NE-Brazil), which were characterized by their physical-chemical conditions and granulometry, in addition to the physical fractionation of soil organic matter (SOM) to determine organic and inorganic P in the SOM fractions (MOP and MOAM). The results obtained indicate an increase in total phosphorus (Pt) content in the affected mangroves, with an average of 143.9±62.3 mg kg-1, while unaffected mangroves had an average of 88.7±37.3 mg kg-1, mainly in its organic forms, with an average of 106.5±48.5 mg kg-1, as well as a higher content of P associated with particulate organic matter (COP; 96.1±105.0 mg kg-1) and associated with minerals (COAM; 86.9±50.7 mg kg-1), despitenot showing a significant increase in the C content in the soil, with emphasis on COP, where it was possible to observe a greater input and lower stabilization of this P. Enzymatic activity, however, did not show significant differences between the areas studied. Thus, it can be observed that effluents from shrimp farming directly impact P dynamics in mangroves, significantly increasing its more bioavailable and less stable forms, in addition to altering the physical-chemical properties of the areas, compromising the natural conditions of this soil. Tipo: Dissertação 2026-01-01T00:00:00Z http://repositorio.ufc.br/handle/riufc/84867 Título: Efeitos do lodo de curtume compostado nos atributos químicos e biológicos do solo e na cultura do milho Autor(es): Felipe, Erivan Araújo Abstract: Population growth has driven the generation of wastes from urban and industrial activities, causing serious environmental problems such as soil contamination and groundwater. These organic wastes with high concentrations of chemicals, such as hydroxides, sulfides and sulfates, as well as the presence of heavy metals, have a high potential for environmental pollution. This study aimed to evaluate the effects of the application of composted tannery sludge (CTS) on the chemical and microbiological properties of the soil and the development of corn. To evaluate these implications were applied five sludge concentrations of CTS in the soil, 0.0; 2.0; 5.0; 10.0; 20.0 and 40.0 Mg.ha-1. The results for the heavy metals, chemical and biological attribute of the soil, as well as biometric were submitted regression analysis and multivariate analysis. The addition of CTS contributes to the increase of the metals in the soil, with values ranging between 8.0 and 16.3 mg.kg-1 for Cu, 4.6 and 25.9 mg.kg-1 for Cr, 18. 8 and 21.3 mg.kg-1 for Zn and 10.3 and 13.9 mg.kg-1 to Pb. The metals Cr, Cu and Ni have a high affinity with the organic fraction. The evaluated metals showed values within the limits allowed for the use of waste in agriculture according to the “Conselho Nacional do Meio Ambiente” (CONAMA). The metals Cr, Cu and Ni have a high affinity with the organic fraction, while Mn, Fe and Zn were found in higher concentrations linked to oxidic fraction. On the other hand, Pb showed affinity for the organic fractions, oxidic and exchangeable. The CTS promoted an increase of the soil pH ranging between 5.7 and 6.5, contributes to the increase of microbial biomass carbon (MBC) and the basal soil respiration (BSR). The addition of CTS up to 20 Mg ha-1 favored the development of corn with plant height ranging from 102 to 132.4 cm. Thus, we conclude that the addition of CTS contributes to the increase of heavy metals in soil. However, the concentrations were within the range values allowed in agriculture; The metals Cr, Cu and Ni have lower bioavailability for soil solution, remaining connected to the organic fraction. The Mn, Fe and Zn have less influence of soil pH, because they are linked to oxidic fraction; But the Pb is highly mobile in soil, due to its affinity for the organic fraction, oxidic and the exchangeable fraction, being the last fraction highly influenced by soil pH change; CTS application contributes to improvement of the chemical and biological soil attributes and growth development of corn, favoring the production of shoots and roots. Cr, Cu, Pb, Zn, Ni, Zn and Fe, generally have low correlations with the chemical and biological soil attributes. Tipo: Dissertação 2015-01-01T00:00:00Z