TEDE Coleção:

Produção, decomposição de palhada e liberação de nutrientes por plantas de cobertura em sistemas integrados na região Meio-Norte

2026-03-20T12:29:08Z

Título: Produção, decomposição de palhada e liberação de nutrientes por plantas de cobertura em sistemas integrados na região Meio-Norte Autor: PINTO JÚNIOR, Fernando Freitas Primeiro orientador: MARQUES, Jordânio Inácio Abstract: Piauí and Maranhão make up the northern portion of MATOPIBA, contributing significantly to increased production in this region due to the existence of arable land still available for expansion. Agricultural areas exhibit high variability in soil types, climate, and vegetation, which directly affects soil fertility and organic matter content and stocks. In addition, the different possibilities for land use and occupation make soil and organic matter management a complex and relevant factor for the sustainability of agriculture in this part of the Northeast. Integrated systems are an important alternative for optimizing the use of natural resources with synergies between agricultural production, in the economic and environmental spheres. Although integrated systems are recognized as relevant to the sustainability of agroecosystems, research is still needed to identify promising cover crops in the challenging soil and climate conditions of the Mid-North region. The objective was to evaluate biomass production, decomposition dynamics, and nutrient release of forage grass species in consortium with corn, used as ground cover crops in integrated production systems in the Mid-North Cerrado of Brazil. The experiments were conducted in an Agroforestry System (ILF) at Fazenda Vó Desidério, in Bom Jesus-PI, in the Cerrado of Southwest Piauí, and in an Agro-Livestock System (ILP) at Fazenda Barbosa, in Brejo-MA, in Eastern Maranhão. The experimental design was randomized blocks with five treatments and four replicates. The treatments were: forage grasses of the genus Megathyrsus and Urochloa in consortium with corn and corn alone, as a control. Plant residue decomposition, grain yield and dry forage mass, and soil fertility were evaluated. The data were submitted and verified for normality and homogeneity of variances and subjected to analysis of variance. When significant, productivity data (grass biomass and corn and soybean grains) and nutrient contents were compared using Tukey's test (P<0.05). There was no significant effect on residual biomass production in Brejo-MA. In Bom Jesus-PI, M+Massai differed from the other treatments. For soil fertility after intercropping, only the chemical attributes K+ , Fe3+ and Mn in Bom Jesus and Zn in Brejo showed a difference. There was a significant effect on soybean productivity in Bom Jesus. The M+Ruziziensis intercrops in Bom Jesus provide greater availability of K+ , Fe3+ and Mn in the soil. In Brejo M+Marandu, it provides an increase in Zn. The intercropping of forage grasses of the genus Megathyrsus and Urochloa does not reduce corn productivity when intercropped. The cultivation of M+Ruziziensis in Bom Jesus and M+Tamani in Brejo, although not resulting in increased soybean productivity, shows potential as cover crops in the Cerrado of the Mid-North region of Brazil. Further studies are needed to assess the long-term effects of the interaction between the corn and forage grass intercropping system on soil fertility, nutrient cycling, and intercropping system productivity under other experimental or seasonal conditions. Instituição: Universidade Federal do Maranhão Tipo do documento: Dissertação

Lógica fuzzy aplicada à modelagem do risco de incêndios florestais no bioma Cerrado, Brasil

2026-03-17T17:35:48Z

Título: Lógica fuzzy aplicada à modelagem do risco de incêndios florestais no bioma Cerrado, Brasil Autor: SOUSA, Andreza Maciel de Primeiro orientador: MACHADO, Nítalo André Farias Abstract: Wildfires cause environmental and socioeconomic impacts by compromising soil quality, vegetation, and natural resources. In the Cerrado biome, despite the recurrence of fire, the factors associated with large-scale wildfires are still poorly understood. The objective of this study was to develop and validate a wildfire risk (WR) model for the Cerrado biome using fuzzy logic. In Chapter 1, a literature review is presented that aims to introduce key concepts and contextualize the Cerrado in light of current environmental and socioeconomic challenges. In Chapter 2, the study on WR modeling using fuzzy logic and GIS is presented, integrating biotic, abiotic, and anthropogenic factors for the Brazilian Cerrado. The WR model was developed using the fuzzy gamma overlay method. The validation was performed through cluster analysis and the construction of a dendrogram between the WR classes and wildfire hotspot data from the Brazilian National Institute for Space Research (INPE), complemented by Kernel density analysis. The “moderate” and “high” wildfire risk classes represented 68.35% and 28.43% of the biome, respectively. There was a greater concentration of these classes in the centralsouthern and southeastern regions of the Cerrado. The variables land use and land cover, roads, population density, precipitation, mean temperature, and water deficit were identified as the most influential variables in the modeling. Kernel density analysis of fire hotspots recorded by the Brazilian National Institute for Space Research (INPE) revealed critical areas along the agricultural frontier of MATOPIBA, which was also identified as a critical area in the WR model. The dendrogram revealed two main groups: (1) “high” risk, associated with fire risk, and (2) “moderate” risk, associated with wildfire frequency, both derived from data provided by the Brazilian National Institute for Space Research (INPE). Meanwhile, the “low” and “very high” risk classes remained isolated at the adopted cut level, validating the quality of the developed model. In conclusion, the developed model proved effective in predicting and identifying wildfire risk areas in the Cerrado. In addition, it demonstrated potential for application in other regions due to its low processing cost, thereby contributing to the development of wildfire prevention and suppression strategies. Instituição: Universidade Federal do Maranhão Tipo do documento: Dissertação

Genealogia e base genetica dos cultivares brasileiros de feijão-caupi ( Vigna unguiculata (L.) Walp.)

2026-03-06T17:06:19Z

Título: Genealogia e base genetica dos cultivares brasileiros de feijão-caupi ( Vigna unguiculata (L.) Walp.) Autor: MEIRELES, Marcos Garreto Primeiro orientador: NASCIMENTO, Wellington Ferreira do Abstract: The expansion of production areas and consumer market of cowpea (Vigna unguiculata (L.) Walp.) has led to new demands on the objectives of genetic improvement of the crop. In this context, the knowledge of the status of the genetic base of this crop is of fundamental importance for the management and conservation of this genetic resource. The objective of this work is to estimate the genetic base of the cowpea cultivars recommended and released in Brazil between the years 1960 and 2020, to identify the ancestors of each cultivar, as well as to identify the origin of their cytoplasmic genes. To obtain this information, the pedigrees of the cultivars were elaborated. Forty-five cowpea cultivars were found to come from the crossing between 81 genotypes. Regarding the relative genetic contribution of the ancestors, it was observed that Pitiúba has contributed with 3.01% for the formation of cultivars, followed by Seridó and CNC 0434 each contributing with 2.81% and 2.78%, respectively. Next are Guariba, Vita 3 and Sempre Verde contributing 2.11% each, and Tvu 410 contributing 2.06%. Together, these contribute 16.98% of the total gene pool of the cultivars. Still worth mentioning are 19 ancestors that participated with 37% of the genetic base of the 45 cultivars. Regarding the origin of the cytoplasmic genes, of the 81 ancestors used in the crossings of cultivars, 38 were used as female genitors. Being the ancestors Pitiúba, CNC 0434, Seridó, IT85F-2687 and BR10 Piauí, the most significant cytoplasmic ancestral sources. Based on the data obtained, we have that the genetic base of the cowpea bean is relatively narrow. Instituição: Universidade Federal do Maranhão Tipo do documento: Dissertação

Ecologia comportamental de Poecilia Sarrafae Bragança & Costa, 2011 (Cyprinodontiformes: poeciliidae)

2026-02-27T15:54:57Z

Título: Ecologia comportamental de Poecilia Sarrafae Bragança & Costa, 2011 (Cyprinodontiformes: poeciliidae) Autor: VIANA, Shyrley Glenda de Sousa Primeiro orientador: OTTONI, Felipe Polivanov Abstract: ABSTRACT This study investigates the behavioral ecology of Poecilia sarrafae, a freshwater fish endemic to the Northeastern region of Brazil, occurring in the Munim River basin, with the aim of filling knowledge gaps about its biology and behavior, as well as providing baseline data to support conservation strategies and policies. Research was conducted at three sites in the middle Munim River basin—Aldeia, Chororó, and Repouso do Guerreiro—characterized by distinct water flow regimes. Data collection spanned 14 months and included video recordings, population censuses, and physicochemical analyses of the water. The results demonstrate that water flow, bank structure, and predator presence directly influence spatial use as well as feeding and reproductive behaviors. Environments with slower flow and shallow marginal waters, such as Chororó, favored higher reproductive and feeding activity, although the constant presence of predators may have contributed to the lower frequency of courtship chases at this site. In contrast, the site with stronger flow (Aldeia) exhibited reduced frequencies of feeding and reproductive behaviors but an increased frequency of chases, particularly during the dry season, when the sex ratio was more balanced and no predators were recorded. During the rainy season, however, the increased occurrence of predators coincided with a reduction in chase behavior. Spatial restriction of females also contributed to prolonging the duration of these interactions. Moreover, an increase in female feeding frequency was observed at Aldeia during the rainy season, possibly related to greater energetic demands associated with reproductive interactions and enhanced resource availability. At sites with intermediate flow, such as Repouso do Guerreiro, chases were longer in duration but less frequent, likely due to the higher predator abundance recorded in this environment. The ethogram constructed revealed distinct behavioral patterns, highlighting variations in reproductive, feeding, and agonistic behaviors. Preliminary analyses further suggest that individual abundance and morphology significantly influence reproductive behavior, particularly under more stable environmental conditions. In addition, a negative association was observed between male chasing activity and female feeding frequency, indicating a potential behavioral cost of reproduction. Overall, the findings underscore the importance of the interplay among environmental factors, predation risk, and social composition in shaping the behavior of P. sarrafae, thereby offering novel insights into the behavioral ecology of poeciliids. Instituição: Universidade Federal do Maranhão Tipo do documento: Dissertação