ABSTRACT Enthalpy is currently suggested as a suitable index for assessing the internal environment of poultry production, primarily dependents on air temperature and relative air humidity. This study aimed to analyze enthalpy in bird production in Londrina, located in the northern region of Paraná, Brazil, and to model the comfort enthalpy required for enhanced production efficiency. Data from 1961 to 2021 from the Instituto Nacional de Meteorologia (INMET), Brasília, Federal District, Brazil, were utilized to compare the thermal comfort conditions and critical limits set for the birds. The meteorological data from this period were scrutinized to understand their variations and interrelationship through a descriptive study and correlation analysis of different parameters. The research findings, based on the enthalpy indices derive historical averages, suggest that heating is crucial for birds during the first and second weeks of housing, during the winter, given the location’s low temperatures. For birds housed during the third to sixth weeks of age, the enthalpy indices indicated the necessity of cooling systems.

RESUMO A entalpia tem sido proposta atualmente como um índice adequado para a avaliação do ambiente interno de galpões de frangos de corte, pois depende basicamente da temperatura e da umidade relativa do ar. Dessa forma, objetivou-se analisar a entalpia como índice de conforto térmico na produção de aves para o município de Londrina, Paraná, e modelar a entalpia aos índices de conforto térmico que proporcionam eficiência na produção. Para o estudo, utilizaram-se dados de 1961 a 2021 do Instituto Nacional de Meteorologia (INMET), de Brasília, Distrito Federal. Os dados meteorológicos desse período foram analisados para conhecer suas variações e as relações entre eles, através de um estudo descritivo e de correlação entre diferentes parâmetros, para comparar as condições de conforto térmico e os limites críticos estabelecidos para as aves. Com base nos resultados desta pesquisa, considerando os índices de entalpia obtidos através de médias históricas, pode-se concluir que a utilização de aquecimento para as aves na primeira e segunda semanas de alojamento, no período de inverno, considerando o local estudado, é imprescindível, devido às baixas temperaturas registadas. Para aves alojadas na terceira, quarta, quinta e sexta semana de idade, considerando os índices de entalpia, pode-se concluir que é necessária a utilização de sistemas de resfriamento para as aves.

ABSTRACT Brazil is one of the world’s largest producers and exporters of animal protein, and swine farming plays a significant role in this sector. With the increase in the prices of mineral fertilizers, swine manure can be an alternative for fertilization and reduce production costs if carefully monitored to minimize damage and environmental impacts. The objective of this study was to characterize swine liquid slurry from a commercial finishing farm and determine the concentrations of total nitrogen, N-NH4 +, total phosphorus, and potassium for its use as a source of nutrients for the soil. The manure volume was calculated. The body retention of nitrogen, phosphorus, and potassium and physical and chemical attributes of the feed and manure were evaluated. In the analyzed swine manure, the concentrations of the total nitrogen, ammoniacal nitrogen, total phosphorus, and potassium were 6.14, 2.87, 3.66, and 2.64 g L-1, respectively. Liquid swine manure proved to be an efficient substitute for nitrogen, phosphorus, and potassium chemical fertilizers, representing cost savings of R$11,743.44 in chemical fertilizers.

RESUMO O Brasil é um dos maiores produtores e exportadores mundiais de proteína animal, e a suinocultura desempenha um papel significativo neste setor. Com o aumento dos preços dos fertilizantes minerais, o dejeto de suínos pode ser uma alternativa para adubação e redução dos custos de produção se monitorado cuidadosamente para minimizar danos e impactos ambientais. O objetivo do estudo foi caracterizar os dejetos líquidos suínos de uma granja comercial de terminação e determinar as concentrações de nitrogênio total, N-NH4 +, fósforo total e potássio, para sua utilização como fonte de nutrientes ao solo. O volume de esterco foi calculado. Foram avaliadas a retenção corporal de nitrogênio, fósforo e potássio e os atributos físicos e químicos da ração e do esterco. Nos dejetos de suínos analisados, as concentrações de nitrogênio total, nitrogênio amoniacal, fósforo total e potássio foram 6,14, 2,87, 3,66 e 2,64 g L de nitrogênio total, nitrogênio amoniacal, fósforo total e potássio, respectivamente. O esterco líquido de suínos mostrou-se um eficiente substituto dos fertilizantes químicos nitrogenados, fosfatados e potássicos, representando economia de R$ 11.743,44 em fertilizantes químicos.

RESUMO Os sistemas de produção de suínos contribuem com emissões de gases de efeito estufa (dióxido de carbono - CO2, óxido nitroso - N2O e metano - CH4) e amônia - NH3 para a atmosfera. Portanto, o objetivo deste estudo foi avaliar metodologias para determinação das emissões de amônia e gases de efeito estufa em uma unidade de produção comercial de suínos durante a fase de terminação, que possui ventilação natural. Foram medidas as concentrações de gases no ar pelo analisador de gases (INNOVA 1412) e foi calculada a vazão de emissões considerando a taxa de ventilação e as diferenças de concentração de gases entre o interior e o exterior da instalação. Os resultados mostraram que a vazão de emissão obtida pela metodologia simplificada em [g suíno por hora] foi: 2,689 para CO2, 0,30 para N2O, 4,39 para CH4, 13,55 para NH3 e 3,273 para vapor d’água. A vazão obtida para a metodologia contínua em [g suíno por hora] foi de 574 para CO2, 0,67 para N2O, 19,50 para CH4, 5,84 para NH3 e 7,2 para vapor d’água. A metodologia simplificada foi altamente precisa para estimar as emissões de GEE em sistemas de produção de suínos com ventilação natural.

ABSTRACT Swine production systems contribute to emission of greenhouse gases (CO2, N2O, and CH4) and ammonia (NH3) into the atmosphere. Therefore, the objective of this study was to evaluate methods for determining the emissions of ammonia and greenhouse gases (GHG) in a commercial swine production unit with natural ventilation during the finishing phase. The concentrations of gases in the air were measured using a gas analyzer (INNOVA 1412), and the flow emission was calculated by considering the ventilation rate and the differences in gas concentration between the interior and exterior of the installation. The results showed that the emission flow obtained via the simplified method in [g per swine h-1] was 2.689, 0.30, 4.39, 13.55, and 3.273 for CO2, N2O, CH4, NH3, and water vapor, respectively. The flow obtained using the continuous method in [g per swine h-1] was 574, 0.67, 19.50, 5.84, and 7.2 for CO2, N2O, CH4, NH3, and water vapor, respectively. The proposed simplified method was highly accurate for estimating GHG emissions from swine production systems with natural ventilation.

Resumen Introducción y objetivo. La corrección de la ginecomastia se encuentra entre las cirugías estéticas más solicitadas por los pacientes masculinos. La principal complicación de este procedimiento es el hematoma postoperatorio. Describimos nuestra experiencia con el uso de la red hemostática percutánea para reducir la incidencia de hematoma postoperatorio, sin el uso de drenajes. Material y método. Evaluamos 13 pacientes operados de ginecomastia con edades compreendidas entre los 15 y los 59 años; un total de 25 mamas. Realizamos la red hemostática en los segmentos superior, inferior y areolar, con hilo de Prolene 2.0 o 3.0 y aguja cilíndrica, después de la hemostasia y antes de cerrar la incisión de la adenectomía, por lo tanto, bajo observación directa. No utilizamos drenajes en ninguno de los pacientes de esta serie y retiramos la malla entre 48 y 96 horas de postoperatorio. Resultados. Del total de 25 mamas operadas, solo 1 presentó hematoma limitado a la región retroareolar, siendo el primer caso de esta serie en el que no habíamos realizado la malla en el segmento areolar. La red no causó ninguna secuela cicatricial (marcas em la piel) ni pigmentación em los punto de transfixión de la aguja. Conclusiones. En nuestra experiencia, el uso de la red hemostática fue un procedimiento adicional al tratamiento de la ginecomastia y resultó eficaz en la prevención del hematoma postoperatorio.

Abstract Background and objective. Correction of gynecomastia is among the most requested cosmetic surgeries by male patients. The main complication of this procedure is postoperative hematoma. We describe the use of a percutaneous hemostatic network to reduce the incidence of postoperative hematoma, without the use of drains. Methods. Thirteen patients were evaluated, aged between 15 and 59 years, in a total of 25 breasts. The hemostatic net was performed in the upper, lower and areolar segments, with 2.0 or 3.0 Prolene with a cylindrical needle, after hemostasis, before closing the adenectomy incision, therefore under direct vision. Drains were not used in any of the patients in this series. The mesh was removed between 48 and 96 hours. Results. Of the total of 25 breasts, only 1 had a hematoma, limited to the retro-areolar region, which was the first case in this series in which the mesh was not performed in the areolar segment. Net did not produced any sequel scar (skin marks) not pigmentation at the needle transfixation sites. Conclusions. In our experience, the use of the hemostatic net was an additional procedure to the treatment of gynecomastia, having been efficient in the prevention of postoperative hematoma.

Resumo Introdução e objetivo. A correção da ginecomastia está entre as cirurgias estéticas mais solicitadas pelos pacientes do sexo masculino. A principal complicação deste procedimento é o hematoma no pós-operatório. Aqui descrevemos a utilização de rede hemostática percutânea para diminuir a incidência de hematoma no pós-operatório, prescindindo da utilização de drenos. Métodos. Foram avaliados 13 pacientes, com idade entre 15 e 59 anos, no total de 25 mamas. A rede hemostática foi realizada nos segmentos superior, inferior e areolar, com fio Prolene 2.0 ou 3.0 com agulha cilíndrica, após a hemostasia, antes do fechamento da incisão da adenectomia, portanto sob visão direta. Em nenhum paciente desta série foram utilizados drenos. A rede foi retirada entre 48 e 96 horas. Resultados. Do total de 25 mamas apenas em 1 ocorreu hematoma, limitado à região retro-areolar, tendo sido o primeiro caso desta série onde não foi realizado a rede no segmento areolar. A rede não causou nenhuma sequela cicatricial (marcas na pele) nem pigmentação nos locais da transfixação da agulha. Conclusão. Em nossa experiência, a utilização da rede hemostática foi um procedimento adicional ao tratamento da ginecomastia, tendo sido eficiente na prevenção do hematoma pós-operatório.

ABSTRACT Sugarcane culture in Brazil has expanded the planting area to degraded pastures and sandy soils. Sugarcane field reform is carried out after five or more harvest cycles, with conventional tillage, followed by planting sugarcane, or growing soybeans or a cover crop. This study aimed to analyze the effects of these different managements in the conventional sugarcane reform on the physical properties and organic carbon in an Argissolo Vermelho distrófico arênico (sandy Ultisol), located at latitude 21° 13’ 40” south, longitude 50° 52’ 06” west, and altitude of 449 m. In each management study, areas of 10 ha were delimited in which 36 months after the renovation period, during the 3rd crop cycle, soil samples were collected in eight trenches measuring 1.0 × 1.0 × 0.5 m, 30 m apart between the crop rows and 0.25 m from the planting furrow, to analyze: the stability index of aggregates in the layers of 0.00-0.10 and 0.10-0.20 m and density and porosity (total, macro, and microporosity) of the soil in addition to organic carbon, in the layers of 0.00-0.10, 0.10-0.20, 0.20-0.30 and 0.30-0.40 m. The results allowed us to conclude that the tillage+sugarcane and tillage+soy managements negatively affected the physical properties compared to the tillage+cover crop management, whose use of Crotalaria spectabilis provided higher Pt, higher Ma, and Mi, higher AS. Furthermore, the increase in carbon contents was low, with small variations between treatments.

Abstract The presence of unsaturated flow in tropical lateritic soils of unknown hydromechanical behavior may lead to severe geotechnical problems. It is known that soil-water characteristic curves (SWCC) are a valuable tool to define this behavior and facilitate the suction estimation, acting on tests performed with no control of such parameter. This article aimed to determine and model the SWCC for 3 unprecedented tropical soils, in the undisturbed and the compacted conditions, from the Paraná state, located in the south of Brazil. The soils studied are one clay and two sands, all lateritic. The pressure plate and the filter paper methods were used to determine the SWCC. The samples were carved and submitted to the drying paths. Furthermore, Mercury Intrusion Porosimetry (MIP) tests were performed in samples of the studied soils in order to obtain the pore size distribution (PSD), contributing to the bimodal definition of curves and the prediction of SWCC main parameters. Both techniques (pressure plate and filter paper) were combined and the SWCC was adjusted by Gitirana & Fredlund model, which efficiently represents the shape of the traditional curves for tropical soils. Furthermore, the SWCCs were predicted by PSD and obtained satisfactory numerical fits. All SWCC presented air entry values in the macropores that are characteristic of soils as the lateritic, given that its structure was considered a key factor in the shape of the curves.

ABSTRACT Heavy clayey Ferralsols are known for their high capacity to form water-stable macroaggregates. However, little is known about how different size classes of macroaggregates exchange mass with increasing organic matter content. This study aimed to characterize and detail aggregation dynamics with increasing organic matter content in these soils. Profiles of three heavy clayey Ferralsols were sampled to isolate the role of organic matter on the stability of aggregates. In this sampling scenario, a conceptual model was established to calculate the aggregation rate of different size classes of water-stable aggregates. This approach allowed the establishment of a critical value for classifying microaggregates in the studied soils (≤0.50 mm) based on their behavior as “building blocks” for macroaggregates when organic matter content is increased. In surface soil layers, where organic matter is higher, most dynamics are expected to happen between macroaggregates classes because free microaggregates are scarce. Consequently, it is important to subdivide macroaggregates into different size classes when evaluating their stability. Quantifying macroaggregates as a single class (e.g., >0.25 or >0.50 mm) was insufficient in representing the macroaggregation dynamics in heavy clayey Ferralsols.

Abstract Background and objective. Alterations in the gluteal region after significant weight loss or bariatric surgery appear as sagging skin, reduced adipose tissue and loss of muscle mass, causing a variety of complaints from patients. Unlike the authors who pre-define the amount of tissue to be resected in the sacral region, we performed this refinement at the end of the operation, allowing the removal of more skin, correcting asymmetric aspects and shaping the gluteal sulcus, depending on the individual anatomy. Methods. Fifteen patients underwent gluteal lifting. In 12 we used an adipose flap to project the upper half of the gluteal region. In 3 of them, in addition to the adipose flap, we included a silicone prosthesis through the same incision. Results. Among our 15 patients we noticed the following occurrences: 1 case of hematoma treated only with aspiration puncture; 2 cases of seroma with spontaneous drainage through the surgical wound; and 2 cases of partial dehiscence of the sutures, with scar revision required in only 1 of these cases. Conclusions. In our experience, the skin adjustment of the sacral region performed at the end of a gluteal lifting, provides better symmetry and more precise positioning of the new gluteal groove.

Resumo Introdução e objetivo. Alterações na região glútea após perda significativa de peso ou cirurgia bariátrica, aparecem como flacidez da pele, redução do tecido adiposo e perda de massa muscular, provocando uma variedade de queixas dos pacientes. Ao contrário dos autores que pré-definem a quantidade de tecido a ser ressecada na região sacral, realizamos esse refinamento no final da operação, permitindo a retirada de mais pele, corrigindo aspectos assimétricos e moldando o sulco glúteo, dependendo da anatomia individual. Método. Quinze pacientes foram submetidos a lifting glúteo. Em 12 usamos um retalho de adiposo para a projeção da metade superior da região glútea. Em 3 deles, além do retalho adiposo, incluímos uma prótese de silicone através da mesma incisão. Resultados. Entre os 15 pacientes atendidos, notamos as seguintes ocorrências: 1 caso de hematoma tratado apenas com punção aspirativa; 2 casos de seroma com drenagem espontânea através da ferida cirúrgica; e 2 casos de deiscência parcial das suturas com revisão da cicatriz necessária em apenas 1 desses casos. Conclusão. Em nossa experiência, o ajuste cutâneo da região sacral, realizado no final de um lifting glúteo, proporciona melhor simetria e posicionamento mais preciso do novo sulco glúteo.

Resumen Introducción y objetivo. Las alteraciones en la región glútea después de una pérdida significativa de peso o una cirugía bariátrica aparecen como piel fácida, reducción de tejido adiposo y pérdida de masa muscular, provocando diversas quejas entre los pacientes. A diferencia de los autores que predefinen la cantidad de tejido a resecar en la región sacra, empleamos este refinamiento al final de la operación, permitiendo la retirada de más piel, corrigiendo asimetrías y dando forma al surco glúteo, según la anatomia de cada individuo. Material y método. Sometimos a lifting glúteo a 15 pacientes. En 12 usamos un colgajo adiposo para proyectar la mitad superior de la región glútea. En 3, además del colgajo adiposo incluimos una prótesis de silicona a través de la misma incisión. Resultados. Entre los 15 pacientes atendidos recogimos las siguientes complicaciones: 1 caso de hematoma tratado solo con aspiración mediante punción; 2 casos de seroma con drenaje espontáneo a través de la herida quirúrgica; y 2 casos de dehiscencia parcial de suturas, con revisión de la cicatriz solo en 1 de estos casos. Conclusiones. En nuestra experiência, el ajuste cutáneo de la región sacra realizado al final de un lifting de glúteos, proporciona una mejor simetría y un posicionamiento más preciso del nuevo surco glúteo.

ABSTRACT: Few approaches have been developed to measure the isolated effect of exchangeable cations on clay dispersion in soils. In this study, the charge sparsity (CS) index was proposed using the ratio between the cations hydrated ionic radius and valence. The index capacity to measure cation effects on clay dispersion in soils was also evaluated. Three Ferralsols, sampled at different sites in Paraná State, Brazil, were homoionized with Ca2+, Mg2+, K+, or Na+ prior to evaluation of the clay dispersion degree. Published independent data for two soils and clays were also used. We tested the capacity of CS and II, the latter proposed by Marchuck and Rengasamy (2011), to predict clay dispersion in soils. The CS predicted the dispersion degree more accuratelly than the ionicity index did, in soils where Ca2+ and Mg2+ behaved similarly. The response of Paraná soils to CS varied with soil characteristics. Soils with a lower pH at the isoelectric point were more dispersible by cations with high CS (K+ and Na+). The CS was efficient to quantify the isolated effect of cations on the clay dispersion process in soils. Therefore, qualitative and quantitative studies can benefit from the CS as an index to understand the effect of cations on clay dispersion in soils.

RESUMO O objetivo do trabalho é avaliar a densidade, a porosidade e a matéria orgânica do solo decorrentes da interação solo-lixiviado em um latossolo vermelho, em duas profundidades: 0,2 e 1,5 m. As amostras de solo foram coletadas indeformadas, e o lixiviado em aterro foi controlado. Utilizaram-se colunas de difusão, sem fluxo, onde o solo ficou submerso no lixiviado durante 90 dias. A matéria orgânica do solo (MOS) foi obtida por meio de determinação gravimétrica (IAPAR). Densidade, micro e macroporosidade foram obtidas de acordo com o ensaio de mesa de tensão (EMBRAPA). Foram realizadas análises de regressão para estudar os efeitos dos fatores e suas interações para o parâmetro da matéria orgânica. As principais conclusões foram: as maiores alterações nas propriedades físicas do solo ocorrem nos primeiros dias de contato; a densidade do solo a 0,2 m reduziu 5,9%, enquanto a 1,5 m aumentou 5,61%; a macroporosidade não se alterou a 0,2 m, mas foi reduzida em 11%, para 1,5 m; a microporosidade para as duas profundidades estudadas aumentou, respectivamente, em 4,25 e 21,14%. A MOS teve baixa correlação com a demanda bioquímica de oxigênio (DBO5) do lixiviado e uma correlação significativa com a sua demanda química de oxigênio (DQO); e seu aumento foi significativo no período de contato.

ABSTRACT The objective of this research is to evaluate soil density, porosity, and also the organic matter due to soil-leachate interaction in Oxisol, at two depths: 0.2 and 1.5 m. Soil samples were collected undisturbed and the leachate in a landfill. Diffusion columns, without any flow, were used, where the soil was submerged in the leachate for 90 days. The organic matter was obtained by gravimetric determination (IAPAR). Density, micro and macro porosity were obtained according to the stress table test (EMBRAPA). Regression analysis was performed to study the factors effects and their interactions for the organic matter parameter. The main conclusions were: major changes in physical soil properties occur in the first days of contact; soil bulk density at 0.2 m decreased by 5.9%, while at 1.5 m it increased by 5.61%; macroporosity did not changed to 0.2 m, but decreased by 11% for 1.5 m; microporosity for both depths studied increased, respectively, by 4.25 and 21,14%. The soil organic matter had a low correlation with the leachate BOD5 and a significant correlation with its COD; the increase of the soil organic matter was significant at the time of the contact.

ABSTRACT Retaining sugarcane straw over the soil after harvesting can improve soil structure and increase soil carbon stabilization, mainly in macroaggregates. We evaluated the carbon content in the aggregate classes in areas under burn and no-burn (adopted for five years) sugarcane management systems, focusing on the superficial layer (0.00-0.20 m). The experiment was carried in an Oxisol and the treatments consisted in burnt sugarcane, manual harvest; burnt sugarcane, mechanized harvest; and no-burn, mechanized harvest. The retention of sugarcane straw on the soil surface is justified by the increase in carbon content and carbon stock in the surface layer (0.00-0.20 m) by restructuring of the soil, even though it cannot match the structure of the soil under native forest. Our results suggest that in no-burn management the carbon not occluded inside aggregates was important to increase carbon stabilization in soil and that more attention should be given to macroaggregates 2.00-8.00 mm present in this management system, that showed higher carbon content and was responsible for increase of the geometric and weight diameter, increasing the erosion resistance in the long term in relation to burn systems.

ABSTRACT Soil and crop management systems change the soil structure, thereby affecting soil quality. The “profil cultural” method (PCM) has been used to identify the effects of management systems on soil structure; however, few studies relate the structures identified by the PCM to quantitative indicators of soil structural quality. This study aimed to quantify soil structures using the PCM and relate these structures to bulk density (Bd), critical bulk density (Bdc), soil aeration capacity (εa), least limiting water range (LLWR), and soil air permeability (Ka) under different soil and crop management systems. The study was developed in a long-term experiment (24 years) involving two systems of soil management (no-tillage and conventional tillage) and two systems of crop management (rotation and succession), resulting in four treatments: no-tillage with crop rotation (NTr), no-tillage with crop succession (NTs), conventional tillage with heavy harrowing and crop rotation (CTr) and conventional tillage with heavy harrowing and crop succession (CTs). The PCM was used to identify the different homogeneous morphological units (HMUs) in the soil profile. Undisturbed soil samples were collected for the HMUs that were most represented in the profiles to determine Ka, LLWR, Bd, and εa. There was agreement between the HMUs and the quantitative indicators. The LLWR showed greater values for Bdc under no-tillage (NTr = 1.36 Mg m-3 and NTs = 1.37 Mg m-3) than under conventional tillage (CTs = 1.31 Mg m-3 and CTr = 1.33 mg m-3). The proportion of samples where Bd > Bdc was 23 % under CTs, 77 % under CTr, 32 % under NTs, and 39 % under NTr. The structures that were most restrictive to root development (CΔ, CΔμ, FmtΔμ, and FmtμΔ) show a lower Ka and greater soil penetration resistance as the soil dries. Pores are more continuous and the structure is less restrictive to plant development in no-tillage than in conventional tillage.

Resumo: O objetivo deste trabalho foi estimar os teores de óxidos de ferro (hematita e goethita) e caracterizar a cor e as assinaturas espectrais e magnéticas de solos do Cerrado de Goiás. Foram estudados seis Latossolos e um Cambissolo. As assinaturas espectrais e magnéticas foram determinadas por espectroscopia de reflectância difusa (ERD) e suscetibilidade magnética, respectivamente. Posteriormente, as curvas espectrais e os cálculos de derivativos secundários foram utilizados para determinar os conteúdos de hematita e goethita, além da cor dos solos após conversão em valores tristimulus. Os teores de hematita e goethita também foram obtidos por difratometria de raios-x, e a cor dos solos também foi avaliada em campo (carta de Munsell). Também foram determinados os valores de substituição isomórfica do ferro por alumínio e o índice de avermelhamento dos solos. A ERD pode ser utilizada para estimar os conteúdos de hematita e goethita, bem como a cor dos solos do Cerrado de Goiás. A assinatura espectral é capaz de apontar as principais características dos solos relacionadas aos conteúdos de matéria orgânica, óxidos de ferro, caulinita e gibbsita. A assinatura magnética, característica de solos ricos em óxidos de ferro (hematita e goethita), mostra o predomínio de minerais pedogenéticos.

Abstract: The objective of this work was to estimate the iron oxide contents (hematite and goethite) and to characterize the color and the spectral and magnetic signatures of Cerrado soils in the state of Goiás, Brazil. Six Oxisols and one Inceptisol were studied. Spectral and magnetic signatures were determined by diffuse reflectance spectroscopy (DRS) and magnetic susceptibility, respectively. Then, the spectral curves and the second derivative calculations were used to determine hematite and goethite contents, as well as soil color after conversion into tristimulus values. Hematite and goethite contents were also obtained by x-ray diffractometry, and soil color was also defined in the field (Munsell color chart). The values for the isomorphic substitution of iron by aluminum and the degree of redness were also determined. DRS can be used to estimate hematite and goethite contents, as well as the color of Cerrado soils in the state of Goiás. The spectral signature can point out the main soil properties related to the contents of organic matter, iron oxides, kaolinite, and gibbsite. The magnetic signature, characteristic of soils rich in iron oxides (hematite and goethite), shows the predominance of pedogenic minerals.

ABSTRACT Soil structure plays an important role in water retention, infiltration capacity, porosity, and penetration resistance. The aim of this study was to evaluate the unsaturated hydraulic conductivity and physical properties of Oxisol soils (bulk density and macro-, micro-, and total porosity) in the structures identified using the profil cultural method in areas under two different management practices (perennial pasture and sugarcane). Three pits were dug in each plot to find out how homogeneous morphological structural units (HMSU) were organized in the soil. Next, unsaturated hydraulic conductivity (Ki) was measured in situ inside each HMSU using a triple-ring infiltrometer at multiple suction. Six samples were collected (two samples for each kind of structural organization in each pit) to determine soil bulk density, total porosity, and macro- and microporosity. Each management practice resulted in a distribution of structures in the soil profile. The behavior of morphologically similar clods was the same, regardless of the physical manipulation of the soil. The distribution of structures based on the management practice determines specific hydraulic conductivities in the soil profile.

RESUMO O estudo resistência do solo a penetração auxilia na compreensão do estado de compactação do solo, indicando a melhor forma de maneja-lo. O presente estudo teve por objetivo verificar a influência do tempo de manejo na modelagem das curvas de resistência do solo à penetração em Latossolo submetido a diferentes uso e manejo de pastagens e mata nativa em condições de campo, utilizando o procedimento de stepwise. O estudo foi realizado na região do Cerrado. Foram avaliados 5 sistemas de uso e manejo de pastagens e mata nativa: ILPF: integração lavoura-pecuária-floresta; ILP: integração lavoura-pecuária; P: Área de pastagem no sistema extensivo; MN: mata nativa; PIQ: piquete rotacionado. Foram avaliados os anos de experimentos 2012/13 e 2013/14. Para a obtenção dos modelos foi realizada uma análise com quatro variáveis independentes: umidade gravimétrica (X1), densidade do solo (X2), porosidade total (X3) e matéria orgânica (X4) e a variável dependente, resistência do solo à penetração (Y). Foi utilizado a análise de regressão múltipla por STEPWISE com F de 0,15. As equações que melhor estimaram a resistencia do solo a penetração foi a RP = 14,68 - 0,26 PT para a Mata Nativa na camada de 0,20 - 0,40 m com indices R2 de 0,97, no ano 1. Para o ano 2 a equação que melhor estimou a resistencia do solo a penetração foi obtida no tratamento PIQ, RP = - 15,94 - 0,29 PT + 15,87 DS + 0,05 MO, com R2 de 0,94. Ao longo de um ano os sistemas de manejos adotados proporcionaram melhora na qualidade física do solo. No segundo ano de experimento foi observada relação positiva da densidade do solo com a resistência do solo a penetração e negativa com umidade gravimétrica do solo.

ABSTRACT The soil resistance to penetration study helps in understanding the state of soil compaction, indicating how best to manage it. The present study aimed to verify the influence of time management in modeling curves of resistance to penetration in Oxisol under different uses and management of pastures and woodland in field conditions, using the stepwise procedure. The study was conducted in the Cerrado region. Five (5) systems of uses and management of pastures and native woodland were evaluated: ILPF: crop-livestock-forest integration; ILP: crop-livestock integration; P: Area in the extensive grazing system; MN: native woodland; PIQ: rotated picket. The experiments were assessed for the years 2012/13 and 2013/14. To obtain the models, an analysis with four independent variables was performed: Gravimetric moisture (X1), bulk density (X2), total porosity (X3) and organic matter (X4) and the dependent variable, soil resistance to penetration (Y). The multiple regression analysis by STEPWISE with F of 0.15 was used. The equation that best estimated the resistance to penetration was RP = 14.68 to 0.26 for Native Woodland in layers from 0.20 - 0.40 m with R2 indices of 0.97 in year 1. For year 2, the equation that estimated the resistance to penetration was obtained in the PIQ treatment, PR = - 15.94 - 0.29 PT + 15.87 DS + 0.05 MO. with R2 of 0.94.