http://repositorio.ufc.br/handle/riufc/110 Fri, 14 Aug 2026 19:53:57 GMT 2026-08-14T19:53:57Z http://repositorio.ufc.br/handle/riufc/87153 Título: Microbioma associado a plantas de carnaúba (Copernicia prunifera): ecologia e aplicações biotecnológicas Autor(es): Silva, Elane Bezerra da Abstract: Carnauba (Copernicia prunifera ), an endemic palm tree of the Brazilian semi arid region, holds high ecological, social, and economic relevance, being widely exploited for wax extraction. Despite its importance, studies addressing soil microbial functioning and the functional potential of the microbiome associate d with this palm tree are still limited, especially under different management conditions and water regimes. In this context, this study aimed to investigate how leaf extraction management and variation in the soil water regime influence soil enzymatic act ivity, bacterial community structure, and the functional potential of microorganisms associated with carnauba. Initially, a bibliometric analysis performed on the Web of Science database (2007 2022; 658 publications) revealed a significant growth in public ations starting from 2014, peaking between 2019 and 2021, mostly focused on the properties and industrial applications of carnauba wax. The study confirmed that research integrating this palm tree into soil sciences is still incipient, validating the need for the experimental investigations conducted in this work. The study was carried out in natural occurrence areas of carnauba in the semi arid region of Ceará, in the municipality of Caucaia, selected based on the combination of two main factors: the presence or absence of leaf extraction management and different soil water regimes (flooded and unflooded). The evaluation of enzymatic activity and stoichiometric relationships showed that the water regime exerts strong control over soil dynamics, reducing total organic carbon, microbial biomass carbon, and the activities of ꞵ glucosidase, arylsulfatase, and acid phosphatase in flooded areas, while urease activity was favored by water saturation. Extractivist management acted as a mitigating factor for these va riations, reducing the variability of enzymatic stoichiometry (C:P ratio) and promoting greater functional stability, although the input of residual biomass intensified microbial phosphorus limitation in managed areas. At the molecular level, 16S rRNA gene amplicon sequencing revealed that management and water regime act as interdependent environmental filters, explaining 43.1% of the total variation in the bacterial community. The interaction between management and seasonal flooding promoted a significant reduction in richness (Chao1) and diversity (Shannon and Simpson), resulting in less complex co occurrence networks dominated by specialist taxa and stress tolerant groups (such as the Bacillota phylum). In contrast, unmanaged and unflooded areas sustained richer, more stable microbiomes with a higher proportion of generalist bacteria. Functional prediction (FAPROTAX) confirmed that preserved areas favor functions associated with phototrophy and nitrogen fixation, while management combined with flooding int flooding intensified anaerobic processes and sulfur cycling. Furthermore, the investigation of ensified anaerobic processes and sulfur cycling. Furthermore, the investigation of the culturable bacteriome showed that carnauba harbors bacteria with plant growththe culturable bacteriome showed that carnauba harbors bacteria with plant growth--promoting potential, especially in root and rhizospheric compartments. Functions such as bipotential, especially in root and rhizospheric compartments. Functions such as biological ological nitrogen fixation, phosphorus and potassium solubilization, and the production of indolenitrogen fixation, phosphorus and potassium solubilization, and the production of indole--33--acetic acid and exopolysaccharides were identified, with variations associated with acetic acid and exopolysaccharides were identified, with variations associated with management conditions and water availability. Integrated, the findings omanagement conditions and water availability. Integrated, the findings of this thesis indicate f this thesis indicate that leaf extraction management, when associated with natural water variations, does not that leaf extraction management, when associated with natural water variations, does not compromise the microbial functionality of carnauba lands and can contribute to the stability compromise the microbial functionality of carnauba lands and can contribute to the stability of soil ecological processes. However, seasonal floof soil ecological processes. However, seasonal flooding exerts the most pronounced oding exerts the most pronounced influence on the microbiome, acting as a critical filter that requires spatial and temporal influence on the microbiome, acting as a critical filter that requires spatial and temporal monitoring to ensure the sustainability of extractivism. In addition, the identification of monitoring to ensure the sustainability of extractivism. In addition, the identification of multifunctional native bacteria opens pmultifunctional native bacteria opens promising perspectives for the development of bioinputs romising perspectives for the development of bioinputs adapted to the edaphoclimatic conditions of the semiadapted to the edaphoclimatic conditions of the semi--arid region, establishing solid bases for arid region, establishing solid bases for future molecular validations and field trials aimed at the biotechnological valorization of future molecular validations and field trials aimed at the biotechnological valorization of carnauba ecosycarnauba ecosystems.stems. Tipo: Tese Thu, 01 Jan 2026 00:00:00 GMT http://repositorio.ufc.br/handle/riufc/87153 2026-01-01T00:00:00Z http://repositorio.ufc.br/handle/riufc/87083 Título: Avaliação da fertilidade em dez unidades de solo cultivadas com cajueiro nos estados do Piauí, Ceará e Rio Grande do Norte Autor(es): Crisóstomo, Lindbergue Araújo Tipo: Tese Tue, 01 Jan 1991 00:00:00 GMT http://repositorio.ufc.br/handle/riufc/87083 1991-01-01T00:00:00Z http://repositorio.ufc.br/handle/riufc/87005 Título: Potencial do biocarvão da casca do coco verde nos atributos do solo e no desenvolvimento do meloeiro Autor(es): Feitosa, Jefferson Ferreira de Freitas Abstract: This investigation addresses the valorization of agro-industrial residues as a strategy to mitigate the physicochemical limitations of soils under fruit cultivation in arid regions. Within this context, this doctoral thesis investigated the feasibility of using green coconut husk-derived biochar as both a soil conditioner and a potassium (K2O) source for muskmelon crops under semi-arid conditions. The research was predicated on the premise that water scarcity, low water-holding capacity in sandy soils, and a heavy reliance on imported potassium fertilizers represent critical challenges for the sustainability and resilience of melon production in the Brazilian Northeast.The experiment followed a completely randomized design (CRD) with six treatments and four replicates, comparing increasing doses of biochar (ranging from 50% to 150% of the recommended K2O for the crop) against conventional fertilization via potassium chloride (KCl). Regarding physical characterization, undisturbed soil samples were collected to determine the water retention curve, fitted using the Van Genuchten model, alongside an analysis of macropore and micropore distribution. At 70 days after sowing (DAS), soil chemical attributes, nutritional status, and plant dry matter accumulation were evaluated.The results demonstrate that the application of green coconut husk biochar promoted significant improvements in soil hydro-physical attributes. Notably, biochar treatments increased water retention capacity; specifically, the dose supplying 100% of the potassium requirement resulted in a 33.3% increase in available soil water compared to the unfertilized control. Chemically and nutritionally, the biochar served as a source of readily available potassium with release regulated by physicochemical properties, consequently increasing soil pH, available K, and organic matter content. Multivariate analysis confirmed that biochar use mitigated soil salinization risks typically associated with KCl. Furthermore, a synergistic effect on nutritional efficiency was observed: the 100% biochar treatment promoted increments of 44.3% in total K accumulation and 25.6% in P accumulation, while the 125% dose increased N accumulation by 30.6%.These improvements translated positively into vegetative development, with significant gains in stem diameter and plant vigor, although the 150% dose indicated physiological saturation. In conclusion, this research highlights green coconut husk biochar as a promising and sustainable alternative for soilmanagement. Its dual function—as a hydro-physical soil improver and a potassium source—contributes to the regional circular economy by repurposing an abundant waste product while simultaneously enhancing the resilience of muskmelon production systems, particularly in environments prone to water stress. Tipo: Tese Thu, 01 Jan 2026 00:00:00 GMT http://repositorio.ufc.br/handle/riufc/87005 2026-01-01T00:00:00Z http://repositorio.ufc.br/handle/riufc/86069 Título: Espectroscopia de reflectância vis-NIR-SWIR-MIR na caracterização de perfis e avaliação de atributos de solos típicos do Nordeste do Brasil Autor(es): Souza, Francisca Evelice Cardoso de Abstract: Soil is essential for life on Earth and for the performance of ecosystem services, making efficient monitoring of its attributes essential. Traditionally, soil is evaluated through wet chemistry laboratory analyses, but this technique has proven to be costly and time consuming. As a promising alternative, remote sensing using reflectance spectroscopy stands out for allowing rapid and low cost pedological analyses, which is especially advantageous for the study of heterogeneous regions susceptible to degradation, such as Northeast Brazil. Given this context, the objectives of this study were: to explore the potential of visible to mid-infrared spectra to characterize the spectral behavior of soils in the Northeast region; to quantify the physical and chemical attributes of these soils, including salinity and sodicity, using spectroscopy in the 350 - 15000 nm range and multivariate statistical algorithms. A total of 114 soil samples were evaluated, covering nine orders, collected from 24 soil profiles distributed across 13 cities in Ceará. Through wet chemistry analyses, the following attributes were determined: organic carbon, total nitrogen, available phosphorus, exchangeable potassium, calcium, magnesium, sodium, and aluminum, electrical conductivity, pH, base sum, cation exchange capacity, base saturation, and sodium saturation percentage. Spectral analysis evaluated soil reflectance in the visible, near infrared, short wave infrared (vis-Nir-SWIR), and mid infrared (MIR) ranges, with data preprocessed using Savitzky Golay smoothing and conversion to absorbance. The results of the conventional analysis were evaluated using descriptive statistics. The smoothed data were subjected to principal component analysis (PCA), and the PCA scores were used for cluster analysis with the unsupervised Fuzzy K means classification algorithm. To quantify the attributes, predictive models were developed with raw and preprocessed spectra using Partial Least Squares Regression, Support Vector Machine with linear and radial kernel functions, and Cubist Algorithm algorithms. The performance of the predictive models was evaluated by the metrics R², RMSE, RPD, and RPIQ. The results of the qualitative analysis rev ealed spectral behaviors with distinct patterns between soil orders. Unsupervised classification grouped samples based on horizon characteristics, with the MIR region showing greater sensitivity to identify more subtle variations between horizons. In the quantitative analysis, all attributes were predicted with at least satisfactory performance, except for calcium, which showed unsatisfactory performance with R² below 0.50. The models developed with MIR data consistently outperformed those in the vis NIR SW IR range for most attributes. The predictions of electrical conductivity and sodium saturation percentage showed reasonable performance, highlighting the potential of the technique for diagnosing soil salinity and sodicity. These highlighting the potential of the technique for diagnosing soil salinity and sodicity. These results confirm the potential of reflectance spectroscopy as an efficient and alternative tool for characterizing and predicting attributes in heterogeneous soils. Tipo: Tese Wed, 01 Jan 2025 00:00:00 GMT http://repositorio.ufc.br/handle/riufc/86069 2025-01-01T00:00:00Z