Doutorado em Agronomia (EA)

URI Permanente para esta coleção

http://200.137.215.59/tede/handle/tde/181

Navegar

Agora exibindo 1 - 6 de 6

Efeitos de culturas de cobertura na qualidade física do solo sob plantio direto
(Universidade Federal de Goiás, 2008-02-22) Andrade, Rui da Silva; Silveira, Pedro Marques da; Stone, Luís Fernando; http://lattes.cnpq.br/0233514913817700
The objective of this study was to verify the suitability of S index in the diagnostic of physical quality of Cerrado soils and, based upon it, to determine the effect of cover crop mulches on physical quality of a Dystrophic Red Latosol (Oxisol) under no-tillage. A total of 2364 samples were selected from the soil data base of Embrapa Rice & Beans and Embrapa Cerrados, covering Cerrado soils from Mid-West, North, and Northeast regions of Brazil. Values of S index, defined as the slope of the soil water retention curve at its inflection point, obtained from these samples were correlated to soil bulk density, macroporosity, and total porosity, considering the following textural classes: very clayey, clayey, sandy clay, sandy clay loam, loam/sandy loam e loamy sand/sand. Based on review of literature, critical values were established for the physical attributes that separated, according to the texture, soils with good and poor structural quality and, based upon they, critical values were established for the S index. In order to study the effect of cover crop mulches on soil physical quality, an experiment was carried out under center pivot at Embrapa Rice & Beans, in Santo Antônio de Goiás, GO, in a randomized block design, with eight replications. The treatments consisted of eight cover crops: Brachiaria brizantha; corn associated with B. brizantha; pigeon pea; millet; Panicum maximum; sorghum; Stylosanthes guianensis; and Crotalaria juncea. The first seven crops had been cultivated in summer season since December 2001 and C. juncea since November 2003. In the winter season, after cover crop desiccation, irrigated common bean crop was implemented under no-tillage. In February 2006, soil organic matter content, some soil physical attributes, and soil physical quality measured by S index were determined. This index was highly correlated to the physical attributes, showing to be an adequate indicator of physical quality of Cerrado soils. The limit value of S = 0.045 showed to be adequate to separate soils with good structure and soils with the tendency to be degraded, while values of S ≤ 0,025 indicate physically degraded soils. Cover crops, specially grasses, favored soil aggregation at surface layer. Soil cultivation modified its structure in comparison to native forest, increasing bulk density and reducing macroporosity and total porosity, and hence, reducing soil physical quality. Among the cover crops, pigeon pea, C. juncea, and corn associated with B. brizantha were those that maintained soil surface layer with good physical quality.
Desempenho agronômico da soja, fertilidade e dinâmica da matéria orgânica em solos sob aplicação de biochar no cerrado brasileiro
(Universidade Federal de Goiás, 2014-05-23) Lima, Larissa Borges de; Petter, Fabiano André; Leandro, Wilson Mozena; http://lattes.cnpq.br/9052207260053937; Leandro, Wilson Mozena; Petter, Fabiano André; Santos, Glênio Guimarães; Borges, Jácomo Divino; Fernandes, Kátia Flávia
The objective of this work was to verify the long-term effect of biochar application on soil chemical properties and the development and soybean yield and carbon pools in a Oxisol (Experiment I) and Haplic Plinthosol (Experiment II) in the cerrado biome. Both experiments were conducted under field conditions in Nova Xavantina-MT . Settled experiments in a randomized block design, consisting of the combination of levels of the fertilizer (NPK) and doses of biochar. For evaluation of soil fertility soil samples were collected at 0-20 cm and analyzed the following attributes: pH, Ca, Mg, H+Al, P, K, and organic matter (OM). Agronomic variables were: height and dry matter of V4 and R1 and productivity. For evaluations in carbon pools contents were determined and total organic carbon (TOC) and nitrogen (TN), the concentrations of C in fractions fulvic acids (FA) , humic acids (HA) and humin (HU) , and , humification index (HI) . In general , there was synergy between the effect of mineral fertilization and application of biochar on soil chemical over the four years after the application attributes. As the aromatic structures are oxidized biochar notes positive effect on the contents of OM. The productivity was significantly increased mainly due to the application of 16 Mg ha-1 of biochar on 1st 3rd and 4th year , with an equation with quadratic behavior . In the 7th and 8th grade direct effect of biochar was reduced with low variation of grain yield. An increase in TOC stocks and aromatic contents with increasing carbon biochar application, showing that Walkley-black method is not effective for the determination of TOC in soils under application of biochar. There was a reduction in C-AF and C-AH with the application of biochar , more evident effect in the presence of NPK . The C-HU increased significantly with increasing doses of biochar. High doses of biochar (>16 Mg ha-1) provide increased IH. In both experiments I and II, biochar contributes to increasing C more stable OM of soil fraction is humin , which is desirable from an environmental standpoint and fertility.
Caracterização fenotípica de acessos crioulos de Phaseolus vulgaris L. do tipo carioca baseada em análise multivariada
(Universidade Federal de Goiás, 2010-08-31) Moçambique, Pedro Antônio; Oliveira, Jaison Pereira de; Costa, Joaquim Geraldo Cáprio da; Carneiro, Monalisa Sampaio; http://lattes.cnpq.br/2696490871291334; Duarte, João Batista; Chaves , Lázaro José; Burle, Marília Lobo; Antunes, Irajá Ferreira; Carneiro, Monalisa Sampaio
Common beans (Phaseolus vulgaris L.) are widely cropped in Brazil, the largest world consumer. P. Vulgaris species is an important source of proteins in the human diet in developing countries in tropical and sub tropical regions, especially in the Americas and West Africa. To know the genetic diversity among commercial and Creole cultivars is very useful to breeders because it allows an adequate organization of the genetic resources and a better exploitation of the available genetic diversity. The objective of this work was to identify the genetic diversity among and into Carioca type common bean accesses stored in the Active Germplasm Bank at Embrapa Arroz e Feijão. The experimental design was a completely randomized bloc with three replicates and carried out at the same institution in the municipality of Santo Antônio de Goiás with the following geographical coordinates: 16.30´S; 49.17´W at 814 m altitude. The evaluation was performed based on fifteen morphoagronomic qualitative descriptors and fifteen quantitative descriptors as well. Nine out of fifteen descriptors were uniform in all accesses. The quantitative descriptors were analyzed using canonical variate analysis; the agglomerative clustering method of Ward, and the univariate variance analysis associated with the Tukey test to evaluate the effect of clustering on the variables and to compare the means of the groups among them. Through the canonical variate analysis it was possible to discard three variables with little contribution to the total phonotypical variability among the accesses. Taking in account the twelve variables left, it was necessary to consider the first five canonical variables to explain 68% of the total variance. Even though the dispersion plot of the accesses related to the two first canonical variables (57%) evidenced phonotypical variability in the accesses studied. Variables flowering days, number of locules per pods and pod beak length were considered the most discriminatory. Accesses CF870015 and CF 830128 were identified as the most diverging between themselves. Through cluster analysis, using the fifteen quantitative descriptors, six similar groups were established. Observing the average of the phenotypic characteristics of each group and the dispersion of the accessions, it was observed concordance between the canonical variate analysis and clustering. Based on the analysis of variance of the quantitative descriptors, the variables leaf width, number of pods per plant, pod beak length and number of locules per pods indicate non significant difference, while the other variables presented highly significant differences at the 5% level.
Nutrição do tomateiro e sua influência no desenvolvimento de ninfas de Bemisia tabaci (GENN.) biótipo B
(Universidade Federal de Goiás, 2012-02-17) Oliveira, Marcos Fernandes; Veloso, Valquiria da Rocha Santos; Fernandes, Paulo Marçal; http://lattes.cnpq.br/9497281141847296; Oliveira Jr, Juarez Patrício de; Nascimento, Abadia dos Reis; Peixoto, Márcio Fernandes; Filho, Miguel Michereff; Fernandes, Paulo Marçal
The objective of this work was to evaluate the effect of tomato plants nutrition on the development of B. tabaci (Genn) biotype B. The experiments were carried out in a completely randomized design in a greenhouse at ambient temperature, moisture and photoperiod, at the Escola de Agronomia e Engenharia de Alimentos (EA/UFG), Goiânia, Goiás, Brasil. Each treatment had eight replicates with one plant per pot. Treatments used to test the various contents of earthworm manure were the association of (soil + earthworm manure: 100% + 0%; 80% + 20%; 60% + 40%; 40% + 60%; 20% + 80%, and 0% + 100%. Treatments used to test the N/K rates were: 1/1; 2/1; 4/1; 8/1; 1/2; 1/4, and 1/8. To test the different sources of organic nitrogen, the following treatments were used: chicken manure; earthworm manure; cotton meal; castor beans meal, as well as the mixtures (chicken manure + earthworm manure + cotton meal + castor beans meal. To test the various sources of mineral nitrogen, the following treatments were used: urea, ammonium sulfate; LL®; calcium nitrate and a mixture of fertilizers (urea + ammonium sulfate + Nitro LL® + calcium nitrate). The infestations were performed 40 days after plugs transplant, by releasing 50 couples of B. tabaci biotype B into screen bags, placed in the third or fourth leaf of each plant. One day after infestation 300 eggs were counted and marked on each infested leaf. Ten days after infestation the amount of unviable eggs were evaluated and first ínstar nymphs marked. The analysis of nymphs development was performed 21 days after infestation in the experiment used to test different sources of nitrogen and N/K rates; and, at 30 days after infestation in the experiments used to test the different levels of earthworm manure. B. tabaci nymphs biotype B showed elongation and mortality in that phase, probably due to antibiosis developed by tomato plants: cultivated in earthworm manure only (egg-adult viability 30% and 44% population reduction); fertilization according to N/K 1/8 rate (egg-adult viability 13% and 69% population reduction); fertilized with chicken manure (30% egg-adult viability and 41% population reduction); and, fertilized with calcium nitrate (25% egg-adult viability and 57% population reduction).
Caracterização de voçorocas em bordas de relevo residual tabular em Quirinópolis
(Universidade Federal de Goiás, 2010-02-25) Sousa, Alik Timóteo de; Correchel, Vladia; http://lattes.cnpq.br/4781536691286837; Correchel, Vladia; Damin, Virgínia; Romão, Patrícia de Araújo; Bakker, Alexandre Pereira de
The city of Quirinópolis, which is located in the Southwest part of Goiás State, in the Basin of Paranaíba River, is consisted by smoothed reliefs containing residual tabular hills whose altitudes range from 370 to 880m. The “Serra da Confusão do Rio Preto”, located in the center part of the city, is representative on the local landscape. In the highest parts of this hill there are many erosive foci, which are of a huge size, especially of gullies type and mainly near of its south edge, where it is developed a big dissected recess containing several headwaters drainage. Two gullies were selected for detailed studies because they are in the same geomorphological situation of a concave edge of a residual relief, however, related to different systems of soil, one on a pedological cover represented by a Red Dusky Soil, Plinthosol petroferric and Gley soil and one on PSAMENT and Histosols . The study aimed to identify the source, the constraints and the evolution of the processes that caused the emergence and evolution of gullies to devise proposals for stabilization and / or appropriate control. Five interviews were carried out with former residents of the hill about the origin and evolution of the selected gullies. Subsequently, thematic maps were produced in the physical environment of use and occupation of the research area and as a source, satellite images Landsat TM (60 m resolution) 1980 and Landsat TM5 (30 m resolution) and SRTM images in 2008, to observe the evolution of land uses and gullies throughout this period. The operational capabilities of the software used were: Envi 4.3, Arc Map - ArcGIS 9.2, Spring 5.0 and CorelDRAW X3 version 13. Then, the entries were drawn erosive events according to the methodology of the IPT. Later on, they were described the horizons of exposed soil on the slopes of gullies in toposequence, with the use of rappelling. The physico-hydric soil characteristics were obtained from field tests of resistance to penetration with an impact penetrometer, saturated hydraulic conductivity using the Guelph permeameter, followed by the characterization of the physical attributes (water content, texture, density particles and soil total porosity, macro and micro) and chemical (pH, OM, Fe, P, K, Ca, Mg, H + Al, Al, CEC and V). Analyses were performed by ANOVA and Tukey test at 5% of probability for the comparison of means. The results showed that the gully of “Córrego do Andre” is developing on old scar erosive, as evidenced by the identification of horizons and / or different soil layers between the right and left slope erosion that probably were deposited by successive cuts and fills. Its evolution is driven by surface flows concentrated on cattle trails that surround it, associated with concentrated flows that spill over the terraces and reach their borders, as well as through the exfiltration of subsurface water in contact horizons Bw Bc or with C underlying the slopes strongly inclined. The Ting gully soils with lower clay in its upper reaches, has low penetration resistance (compaction) and high hydraulic conductivity, so the progression is linked to performance continues the erosion mechanisms represented by the internal pipings. The superficial runoff contributes little to the progression of this erosion.
Frações da matéria orgãnica e atributos biológicos do solo em veredas conservadas e antropizadas no bioma cerrado
(Universidade Federal de Goiás, 2013-08-14) Sousa, Ricardo Fernandes de; Leandro, Wilson Mozena; Brasil, Eliana Paula Fernandes; http://lattes.cnpq.br/7324619074753727; Madari, Beáta Emoke; Leandro, Wilson Mozena; Borges, Jácomo Divino; Figueiredo, Cícero Célio de; Brasil, Eliana Paula Fernandes
Veredas (a type of wetland) are humid ecosystems, generally associated to hydromorphic soils and shallow water table, which occur frequently in the neighborhood of the springs and watercourses in the Cerrado region. The objective of this work was to study the soil of wetlands located in conserved and altered environments (agricultural areas and pastures), by determining the organic matter fractions, and biological attributes of the soil. The study was carried out in the central region of Cerrado biome, in the state of Goiás (Brazil), in wetlands situated in the City of Bela Vista de Goiás. Three wetlands were selected for soil sampling, as follows: a preserved wetland, surrounded by natural vegetation (cerrado); an area disturbed, with the occurrence of pasture around it; and another wetland also disturbed, with the occurrence of annual crops (agriculture) in its surroundings. The samplings were taken during the dry season, in months of July and August of 2012, along reference lines arranged according to their position in the slope, in the upper, middle and lower position, in approximate direction of the drain line of the wetland. Samples were collected at two depths: 0-10 cm and 10-20 cm. The variables studied were: Total soil organic carbon and nitrogen, and soil C:N ratio; C and N contents, and C:N ratios of the particulate and mineral-associated organic matter; fulvic acid, humic acid and humin, and humic acids to fulvic acids ratio, C contents of humic substances and its ratio to total soil organic carbon; carbon and nitrogen contents, and C:N ratio of the microbial biomass; microbial quotient; microbial biomass N to soil total nitrogen ratio; basal soil respiration; metabolic quotient; and fluorescein diacetate (FDA) hydrolytic activities in soil. In the lower position of slope the total soil organic C and N contents (in both depths), and levels of organic carbon in particulate organic matter, humic substances and soil microbial biomass (to 10 cm depth only), are smaller in the agriculture surrounding environment. Also in the lower position of slope in the topsoil, the soil total N, and N levels in particulate organic matter and microbial biomass are significantly larger in the wetland neighboring pastures. In the topsoil, the organic C contents of the mineral-associated soil organic matter fraction are larger in the conserved ecosystem, in all slope positions. In general, the farming in the vicinity of the wetlands promoted changes in soil microbial and biochemical attributes, as well as those related to soil organic matter in these ecosystems, with changes in C and N biogeochemistry processes. These changes are especially pronounced in the lower position of the slopes, with clear differences also between this lower zone and the highest slope positions (upper and middle) of the wetlands.

Navegar

Navegando Doutorado em Agronomia (EA) por Por tipo de Acesso "Acesso aberto"

Resultados por página

Opções de Ordenação