Consensus of the Brazilian association of hematology, hemotherapy and cellular therapy on patient blood management.

Patient Blood Management (PBM) is a multidimensional approach that seeks to optimize the use of blood and its components in patients. This matter emerged as a response to the need to reduce unnecessary exposure to blood transfusions and their potential risks. In the past, blood transfusion was often overused resulting in complications and high costs. The advent of Patient Blood Management has caused a paradigm shift, highlighting anemia prevention, bleeding control and maximizing the production of blood cells by the organism itself. Patient Blood Management guidelines include the early identification of anemia, strategies to minimize blood loss during surgery, intraoperative blood conservation techniques, preoperative hemoglobin optimization and evidence-based approaches to the rational use of blood transfusions. Aiming to improve clinical outcomes, decrease transfusion-related complications and reduce associated costs, this multidisciplinary approach counts on doctors, nurses, pharmacists and other healthcare professionals. Based on research and clinical evidence, Patient Blood Management continues to evolve thereby promoting safer, more effective patient-centered practices. Its implementation has proven beneficial in various medical contexts thereby contributing to improvements in the quality of care provided to patients. Our goal with this Consensus is to present readers with a broad and diverse view of Patient Blood Management so that they have the building blocks to implement this new technique.

Implementation of a patient blood management program based on a low-income country-adapted clinical decision support system

ABSTRACT Introduction: Patient blood management (PBM) programs are associated with better patient outcomes, a reduced number of transfusions and cost-savings The Clinical Decision Support (CDS) systems are valuable tools in this process, but their availability is limited in developing countries This study assesses the feasibility and effectiveness of an adapted CDS system for low-income countries. Methods: This was a prospective study of the PBM program implementation, in a 200-bed tertiary hospital, between February 2019 and May 2020. Outcome measures were red blood cell (RBC), fresh frozen plasma (FFP) and platelet unit transfusions, the transfusion of a single unit of red blood cells and an RBC adequacy index (RAI). Results: Comparing the post-PBM program era with the pre-PBM system era, there was a decrease in red blood cell transfusions (p = 0.05), with an increase in single unit red blood cell transfusions (p = 0.005) and RAI (p < 0.001). Conclusions: The PBM programs, including electronic transfusion guidelines with pre-transfusion medical auditing, was associated with improved transfusion practices and reduced product acquisition-related costs.

Association of preoperative anemia and increased risk of blood transfusion and length of hospital stay in adults undergoing hip and knee arthroplasty: An observational study in a single tertiary center.

BACKGROUND AND AIMS: Anemia is a common feature in patients presenting for major elective surgery, and it is considered an independent risk factor associated with adverse outcomes. Although several studies suggest that preoperative anemia is associated with poor outcomes after elective orthopedic surgery, data are still scarce in middle- and low-income countries where this problem may be even greater. The objective of this study was to evaluate the impact of preoperative anemia in clinical outcomes in patients submitted to hip and knee arthroplasty in a single tertiary hospital. METHODS: Medical records of 234 adult patients submitted to knee and hip arthroplasty from January 2018 to July 2020 were retrospectively reviewed. Patient's demographics (ie, age and gender), pre- and postoperative hemoglobin level (Hb), allogeneic red blood cell (RBC) transfusion, intensive care admission, length of hospital stay, hospital readmissions, and mortality up to 30 days after the surgery were analyzed. Outcomes were evaluated according to preoperative anemia status based on World Health Organization (WHO) criteria. RESULTS: Mean age was 70 years with a slight female predominance (57.6%). The prevalence of anemia was 30.7% (72/234) being more prevalent in female (33.3% vs 26.7%). Preoperative anemia was significantly associated with greater rate of blood transfusion (34.5% vs 5.6%; P = .001), prolonged length of hospital stay (6.48 days vs 3.36 days; P = .001), and higher rate of intensive care unit admission (47.2% and 29.6% P = .009). Preoperative anemia had no effect on 30-day readmission and mortality for both males and females. CONCLUSIONS: Our retrospective study demonstrated that preoperative anemia is a common problem among orthopedic patients and is associated with increased transfusion risk and worse outcomes. Strategies to identify and treat anemic patients before elective surgery are critical to improving clinical outcomes.

Polylactic acid production from biotechnological routes: A review.

Polylactic acid (PLA) has been highlighted as an important polymer due to its high potential for applicability in various areas, such as in the chemical, medical, pharmaceutical or biotechnology field. Very recently, studies have reported its use as a basic component for the production of personal protective equipment (PPE) required for the prevention of Sars-Cov-2 contamination, responsible for the cause of coronavirus disease, which is currently a major worldwide sanitary and social problem. PLA is considered a non-toxic, biodegradable and compostable plastic with interesting characteristics from the industrial point of view, and it emerges as a promising product under the concept of "green plastic", since most of the polymers produced currently are petroleum-based, a non-renewable raw material. Biotechnology routes have been mentioned as potential methodologies for the production of this polymer, especially by enzymatic routes, in particular by use of lipases enzymes. The availability of pure lactic acid isomers is a fundamental aspect of the manufacture of PLA with more interesting mechanical and thermal properties. Due to the technological importance that PLA-based polymers are acquiring, as well as their characteristics and applicability in several fields, especially medical, pharmaceutical and biotechnology, this review article sought to gather very recent information regarding the development of research in this area. The main highlight of this study is that it was carried out from a biotechnological point of view, aiming at a totally green bioplastic production, since the obtaining of lactic acid, which will be used as raw material for the PLA synthesis, until the degradation of the polymer obtained by biological routes.

Development of a purification process via crystallization of xylitol produced for bioprocess using a hemicellulosic hydrolysate from the cashew apple bagasse as feedstock.

Xylitol was biotechnologically produced by Kluyveromyces marxianus ATCC36907 using the hemicellulosic hydrolysate of the cashew apple bagasse (CABHH). Sequentially, the present study investigated the recovery and purification of xylitol evaluating different antisolvents [ethanol, isopropanol and the ionic liquid 2-hydroxyl-ethylammonium acetate (2-HEAA)], their proportion in the medium (10-90% v/v), and their cooling rate (VC 0.25-0.50 °C/min). These processes were contrasted with the crystallization process of commercial xylitol. This study is the first to assess xylitol crystallization using a protic ionic liquid. The hydrolysate obtained from a mild treatment with sulfuric acid contained mainly glucose and xylose at concentrations of 15.7 g/L and 11.9 g/L, respectively. With this bioprocess, a maximum xylitol production of 4.5 g/L was achieved. The performance of the investigated antisolvents was similar in all conditions evaluated in the crystallization process of the commercial xylitol, with no significant difference in yields. For the crystallization processes of the produced xylitol, the best conditions were: 50% (v/v) isopropanol as antisolvent, cooling rate of 0.5 °C/min, with a secondary nucleation of yield and purity of 69.7% and 84.8%, respectively. Under the same linear cooling rate, using ethanol, isopropanol or the protic ionic liquid 2-hydroxyl-ethylammonium acetate (2-HEAA), crystallization did not occur, probably due to the presence of carbohydrates not metabolized by the yeast in the broth, which influences the solubility curve of xylitol. With the results of this work, a possible economical and environmentally friendly process of recovery and purification of xylitol from CABHH could be proposed.

Cost of chronic red blood cell transfusion in the Brazilian private healthcare sector from a payer perspective / Custo de transfusão crônica de concentrado de hemácias na perspectiva do sistema de saúde suplementar brasileiro

Objective: In the private healthcare sector in Brazil, the dearth of information regarding transfusion cost may compromise the management of conditions requiring long-term transfusion. Therefore, the present study aimed to estimate the cost of chronic red blood cell (RBC) transfusion in this context. Methods: A payer perspective was chosen for the analysis. A survey performed by an expert advisory board gathered information on the amounts reimbursed by health plans to blood centers per outpatient transfusion of a single RBC bag in multitransfused patients. Survey results were contrasted to RBC transfusion cost calculated using Brazilian Hierarchical Classification of Medical Procedures (CBHPM) parameters from 2018 and 2010, the latter suggested by the advisory board as more accurately reflecting market prices. Results: Six blood centers in the South and Southeast of Brazil were surveyed. The median amount reimbursed per RBC unit was R$ 1,066.44 (interquartile range: R$ 665.00-1,252.00). The mean amount reimbursed was R$ 959.54 ± R$ 337.14 (minimum: R$ 295.00 ­ maximum: R$ 1,980.00). Using 2018 CBHPM parameters, the cost of transfusing one RBC unit was calculated as R$ 1,905.18. Using 2010 CBHPM parameters, the cost was R$ 1,119.69 per RBC unit. Conclusions: Analyses using 2018 CBHPM parameters may lead to overestimation of transfusion cost. The best estimate for outpatient transfusion of one RBC bag in the private health care sector in Brazil lies between the observed reimbursed values and 2010 CBHPM cost. The present results provide valuable information for future cost-effectiveness analyses focusing on disorders whose treatment involves routine RBC transfusion.

A carência de informações sobre custo de transfusão sanguínea na saúde suplementar brasileira pode comprometer análises econômicas e eventuais decisões relacionadas a esse procedimento no longo prazo. O objetivo deste estudo foi estimar o custo de transfusão crônica de concentrado de hemácias (CH) nesse contexto. Métodos: Foi escolhida a perspectiva do pagador. Uma pesquisa foi realizada com especialistas para levantamento de valores reembolsados para transfusão de uma bolsa de CH em pacientes politransfundidos. Os resultados da pesquisa foram comparados ao custo de transfusão de CH calculado utilizando a Classificação Brasileira Hierarquizada de Procedimentos Médicos (CBHPM), edições de 2018 e 2010, sendo a edição mais antiga sugerida pelos especialistas como estando mais de acordo com a realidade de mercado. Resultados: Seis hemocentros localizados no Sul e Sudeste do Brasil foram incluídos. Os valores mediano e médio reembolsados aos hemocentros foram R$ 1.066,44 (amplitude interquartil: R$ 665,00-1.252,00) e R$ 959,54 ± R$ 337,14 (mínimo: R$ 295,00 ­ máximo: R$ 1.980,00), respectivamente. Com base nos parâmetros da CBHPM 2018 e 2010, os custos de transfusão calculados para uma bolsa de CH foram R$ 1.905,18 e R$ 1.119,69, respectivamente. Conclusões: Análises utilizando parâmetros da CBHPM 2018 podem superestimar os custos de transfusão de CH. Na perspectiva do sistema de saúde suplementar brasileiro, a melhor estimativa de custo de transfusão por bolsa de CH está entre o valor reembolsado e o valor calculado utilizando a CBHPM 2010. O presente estudo apresenta informações importantes para futuras análises de custo-efetividade de patologias que envolvem tratamentos à base de politransfusão de CH.

Variabilidade espacial de atributos físicos de solos antropogênico e não antropogênico na região de Manicoré, AM / Spatial variability of soil physical anthropogenic and non anthropogenic in the region of Manicoré, AM

Melhores conhecimentos sobre os solos antropogênicos podem auxiliar na construção de cenários futuros para a região amazônica, por meio de informações que subsidiem o planejamento sustentável. O objetivo deste trabalho foi avaliar a variabilidade espacial de atributos físicos de solos antropogênicos e não antropogênico na região de Manicoré, AM. Na área do estudo foram selecionadas duas, uma com solos não antropogênicos (floresta nativa) e outra com solos antropogênicos (terra preta arqueológica). Em cada área, foi estabelecida uma malha medindo 70 x 70 m e os solos foram amostrados nos pontos de cruzamento da malha, com espaçamentos regulares de 10 em 10 metros, perfazendo um total de 64 pontos amostrais em cada paisagem. Foram coletadas amostras de solos na profundidade de 0,0 a 0,10 m e realizadas as análises físicas (textura, densidade do solo, macroporosidade, microporososidade, porosidade total e estabilidade dos agregados). Em seguida, os dados foram submetidos á estatística descritiva e geoestatística. Verificou-se que os solos antropogênicos e não antropogênicos apresentaram comportamentos diferenciados em relação ás suas estruturas espaciais. A variabilidade espacial que predominou no solo antropogênico e não antropogênico foi moderada e fraca indicando que estes solos estão fortemente ligados a alterações ocorridas por fatores extrinsecos no solo. No solo antropogênico foi observado melhores resultados para a porosidade total, microporosidade e densidade do solo, evidenciando características superiores para fins agronômicos quando comparado ao solo não antropogênico. E os valores de alcance encontrado nas duas áreas foram acima do utilizado na malha, evidenciando maior continuidade espacial nestes ambientes.

Better knowledge of the anthropogenic soils can help create future scenarios for the Amazon region through information that supports the sustainable planning. The aim of this study was to evaluate the spatial variability of soil physical anthropogenic and not anthropogenic in the region of Manipur, AM. In the study area we selected two, one with no anthropogenic soils (native forest) and another with anthropogenic soils (black earth archaeological). In each area, we established a grid measuring 70 x 70 m and the soils were sampled at the points of intersection of the grid with regular spacing of 10 by 10 feet, making a total of 64 sampling points in each landscape. Soil samples were collected at a depth from 0.0 to 0.10 I did the analyzes physical (texture, bulk density, macroporosity, microporososidade, porosity and aggregate stability). Then, the data were subjected to descriptive statistics and geostatistics. It was found that the anthropogenic and non-anthropogenic soils showed different behaviors in relation ace their spatial structures. The spatial variability that prevailed in anthropogenic and non-anthropogenic soil was moderate and weak indicating that these soils are strongly linked to changes in the soil by extrinsic factors. The soil was observed anthropogenic best results for total porosity, microporosity and bulk density, showing superior characteristics compared for agronomic soil not anthropogenic. And the range of values found in the above two areas were used in the mesh, showing greater spatial continuity in these environments.

Número de amostras na análise geoestatística e na krigagem de mapas de atributos do solo / Number of samples in geostatistical analysis and kriging maps of soil properties

O objetivo deste trabalho foi analisar diferentes intensidades de amostragem do solo com relação à precisão na análise geoestatística e interpolação de mapas, para fins de agricultura de precisão em área de cana-de-açúcar. O solo foi coletado em duas grades regulares na profundidade de 0,00-0,20m para análise granulométrica (área 1) e da fertilidade do solo (área 2). Foram comparadas intensidades de amostragem do solo: 208, 105, 58 e 24 pontos na área 1 e 206, 102 e 53 pontos na área 2. Os dados foram submetidos à análise descritiva e geoestatística. Os variogramas construídos com 105 pontos não diferem dos variogramas com 208 pontos, fato que não ocorre para 58 e 24 pontos. O aumento do intervalo de amostragem e a redução do número de pontos promovem o maior erro na estimativa por krigagem. As amostragens com mais de 100 pontos por área não resultaram em melhorias significativas no erro da estimativa por krigagem, nem diferiram na quantidade de insumos aplicados em campo.

The objective of this study was to analyze different intensities of soil sampling for accuracy in geostatistical analysis and interpolation maps for precision agriculture in the sugarcane area. Soil samples were collected at two regular grids at a depth of 0.00 to 0.20m for granulometric analysis (area 1) and soil fertility (area 2). We compared soil sampling intensities: 208, 105, 58 and 24 points in Area 1 and 206, 102 and 53 points in Area 2. The data were submitted to descriptive analysis and geostatistics. The variograms constructed with 105 points didn't differ from variograms with 208 points, which doesn't occur for 58 and 24 points. The increase of sampling interval and reducing the number of points promote greater error in kriging. Samples with more than 100 points per area did not result in significant improvements in the error of kriging, or differed in the amount of fertilizer applied to the field.

Brazilian experience using high dose sequential chemotherapy followed by autologous hematopoietic stem cell transplantation for malignant lymphomas

OBJECTIVE: To evaluate the use of high-dose sequential chemotherapy in a Brazilian population. METHODS: High-dose cyclophosphamide followed by autologous hematopoietic stem cell transplantation is an effective and feasible therapy for refractory/relapsed lymphomas; this regimen has never before been evaluated in a Brazilian population. All patients (106 with high-grade non-Hodgkin lymphoma and 77 with Hodgkin's lymphoma) submitted to this treatment between 1998 and 2006 were analyzed. Chemotherapy consisted of the sequential administration of high-dose cyclophosphamide (4 or 7 g/m²) and granulocyte-colony stimulating factor (300 µg/day), followed by peripheral blood progenitor cell harvesting, administration of etoposide (2g/m²) and methotrexate (8 g/m² only for Hodgkin's lymphoma) and autologous hematopoietic stem cell transplantation. RESULTS: At diagnosis, non-Hodgkin lymphoma patients had a median age of 45 (range: 8-65) years old, 78 percent had diffuse large B-cell lymphoma and 83 percent had stage III/IV disease. The Hodgkin's lymphoma patients had a median age of 23 (range: 7-68) years old, 64.9 percent had the nodular sclerosis subtype and 65 percent had stage III/IV disease. Nine Hodgkin's lymphoma patients (13 percent) and 10 (9 percent) non-Hodgkin lymphoma patients had some kind of cardiac toxicity. The overall survival, disease-free survival and progression-free survival in Hodgkin's lymphoma were 29 percent, 59 percent and 26 percent, respectively. In non-Hodgkin lymphoma, these values were 40 percent, 49 percent and 31 percent, respectively. High-dose cyclophosphamide-related mortality was 10 percent for Hodgkin's lymphoma and 5 percent for non-Hodgkin lymphoma patients. High-dose cyclophosphamide dosing had no impact on toxicity or survival for both groups. CONCLUSIONS: Despite a greater prevalence of poor prognostic factors, our results are comparable to the literature. The incidence of secondary neoplasias is noteworthy. ...

Geoestatística e atributos do solo em áreas cultivadas com cana-de-açúcar / Geostatistics and soil attributes in area cultivated with sugar cane

Em solos sob cultivo de cana-de-açúcar, o tráfego intenso de máquinas agrícolas pode provocar estado de compactação ao solo. Portanto, o objetivo deste trabalho foi caracterizar a variabilidade espacial de atributos físicos e teor de matéria orgânica de um Latossolo Vermelho eutroférrico gibbsítico (sob Basalto) e Latossolo Vermelho distroférrico caulinítico (sob Arenito) nas profundidades de 0,0-0,2m e 0,2-0,4m, em áreas sob cultivo de cana-de-açúcar. Os solos foram amostrados nos pontos de cruzamento de uma malha, com intervalos regulares de 10m, nas profundidades de 0,0-0,2m e 0,2-0,4m, totalizando 100 pontos para cada área de estudo. Em cada ponto da malha, foram determinados a densidade do solo, a macroporosidade, o teor de matéria orgânica e a resistência do solo à penetração. Os atributos físicos mostram valores de resistência do solo à penetração, da densidade do solo e da macroporosidade acima da média para esses solos. As variáveis em estudo apresentaram um maior alcance e menor coeficiente de variação no LVef em comparação com o LVd, nas profundidades em estudo. Recomenda-se maior número de amostragem para os atributos em estudo no Latossolo Vermelho distrófico e na profundidade de 0,2-0,4m.

The intense traffic of agricultural machines in soils cultivated with sugar cane can cause soil compaction. Therefore, the objective of this research was to characterize the spatial variability of soil physical attributes and content organic matter of a eutroferric Red Latosol gibbisitic (under Basalt) and dystroferric Red Latosol caulinitic (under Sandstone) in the depths of 0.0-0.2m and 0.2-0.4m in areas cultivated with sugar cane. Soils were sampled at the crossing points of a grid at regular intervals of 10m and at depths of 0.0-0.2m and 0.2-0.4m. Bulk density, macroporosity, organic matter content and soil penetration resistance were measured for all sampling points. The physical attributes show values of soil penetration resistance, bulk density and macroporosity above average for these soils. The studied variable presented a larger range and minor variation coefficient in the eutroferric Red Latosol (Oxisol Eutrustox) when compared with the dystroferric Red Latosol (Oxisol Haplustox), in the studied depths. It is recommended a bigger number of samples to study the eutroferric Red Latosol attributes and the depth of 0.2-0.4m.

Variabilidade espacial da textura de um latossolo sob cultivo de citros / Spatial variability of texture in an Oxisol cultivated with citrus

O relevo influencia a variabilidade da textura, uma vez que condiciona o tempo de exposição dos materiais à ação do intemperismo. Neste trabalho, desenvolvido no município de Gavião Peixoto (SP), objetivou-se caracterizar a variabilidade espacial da textura de um Latossolo Vermelho distrófico sob cultivo de citros. A encosta foi dividida em três segmentos: topo, meia encosta e encosta inferior. O solo foi amostrado em malha, com intervalos regulares de 50 m, perfazendo o total de 332 pontos em uma área de 83,5 ha, nas profundidades de 0,0-0,2 m e 0,6-0,8 m. Os dados foram submetidos à análise estatística descritiva e geoestatística (modelagem de semivariogramas e mapas de krigagem). O comportamento espacial da textura de latossolos está diretamente relacionado com as formas do relevo neste estudo, que controla o sentido dos fluxos de água superficial e subsuperficial. O conceito de homogeneidade da distribuição de argila no perfil dos latossolos é uma informação que pode ser ajustada pelo conhecimento do padrão espacial dessa distribuição em diferentes formas do relevo.

Relief influences soil texture variability, since it contributes to the time of exposition of the materials to weathering factors. Our work was carried out in the city of Gavião Peixoto (SP), with the objective of characterizing the spatial variability of texture of a dystrophic Red Latosol cultivated with citrus. The hillside was divided into three segments: top, stocking lean and inferior lean. Soil samples were collected in a grid with regular intervals of 50 m, at the depths of 0.0-0.2 m and 0.6-0.8 m, comprising a total of 332 points in an area of 83.5 ha. The data were submitted to descriptive and geostatistics analyses (semivariogram modeling and kriging maps). The spatial behavior of the texture of oxisols is directly related to the relief forms in this study, which controls the direction of surface and subsurface water flows. The concept of homogeneity of clay distribution in the Oxisol profile is a piece of information that can be adjusted by knowing the spatial pattern of this distribution in different relief forms.

Brazilian experience using high-dose sequential chemotherapy followed by autologous hematopoietic stem cell transplantation for relapsed or refractory Hodgkin lymphoma.

PURPOSE: We evaluate the effectiveness and toxicity of high-dose sequential chemotherapy (HDS) as salvage therapy in patients with advanced-stage Hodgkin lymphoma. PATIENTS AND METHODS: We performed a retrospective analysis on 77 patients receiving HDS between 1998 and 2006. Patients enrolled were in disease progression or relapsed disease, or did not achieve a complete remission after first-line treatment. HDS consisted of the sequential administration of cyclophosphamide and granulocyte colony-stimulating factor with stem cell harvesting, followed by methotrexate plus vincristine and etoposide. RESULTS: The majority of patients had stage III/IV (64%) and B symptoms (71.4%). Disease status improvement after HDS was observed in 24 of 57 patients (42%) previously in disease progression or relapse. HDS-related deaths occurred in 8 of 77 patients (10.4%). Four patients (5.2%) developed acute myeloid leukemia/myelodysplastic syndrome. Overall, disease-free and progression-free survival was 27%, 57%, and 25%, respectively. CONCLUSION: Despite the treatment-related mortality, HDS is feasible, with satisfactory response rates, even in patients with poor prognosis.

Spatial variability of the physical and mineralogical properties of the soil from the areas with variation in landscape shapes

The objective of this work it was to use the geostatistics methods to investigate the spatial relationships between the physical and mineralogical properties of an oxisol planted with the sugarcane in an area of slight variations in the landform. The soil was sampled at 10 m regular intervals in the crossing points of a 100 x 100 m grid. At each point, the soil was collected at 0.0-0.2 m, 0.2-0.4 m and 0.4-0.6 m depths for the analyzes of physical properties and at 0.6-0.8 m for the mineralogical analyses. Both the Kt/Kt+Gb ratio and Kt relative crystallization level were higher in the compartment I than in the compartment II. As a consequence, the soil penetration resistance and bulk density were higher in the compartment I, while the macroporosity and Ksat were lower. Therefore, it was concluded that both the identification and mapping of a landform were efficient for understanding the spatial variability of the soil properties. Moreover, variations in the landscape shape promoted the differentiated variability of the physical and mineralogical soil properties: the more variable the landscape, the more variable was the soil properties.

Este trabalho teve como objetivo avaliar a influência das formas do relevo na variabilidade espacial de atributos físicos e suas relações com a mineralogia da argila de um Latossolo Vermelho eutroférrico, utilizando a técnica da geoestatística. Os solos foram amostrados nos pontos de cruzamento de uma malha, com intervalos regulares de 10 m, nas profundidades de 0,0-0,2 m, 0,2-0,4 m e 0,4-0,6 m para os atributos físicos e 0,6-0,8 m para os atributos mineralógicos. Os valores médios para a densidade do solo e resistência do solo à penetração são maiores no compartimento I onde a relação Ct/Ct+Gb é relativamente maior, indicando a presença de maior teor de caulinita. No compartimento II a condutividade hidráulica e a macroporsidade são maiores, influenciados provavelmente pelo predomínio da gibbsita. Portanto, conclui-se que a identificação das pedoformas é muito eficiente para compreender a variabilidade espacial de propriedades do solo. Sendo que, as variações na forma da paisagem promovem variabilidade espacial diferenciada das propriedades físicas e mineralógicas do solo.

Variação espacial da perda de solo por erosão em diferentes superfícies geomórficas / Spatial variation of the soil loss for erosion in different geomorphic surfaces

O objetivo deste trabalho foi estudar a influência das superfícies geomórficas na variação espacial da perda de solo por erosão na região de Pereira Barreto, São Paulo (SP). Os solos foram amostrados nos pontos de cruzamento de uma malha, georreferenciados, com intervalos de 350m, na profundidade de 0,0-0,2m, totalizando 67 pontos. Foram feitas determinações da composição granulométrica e do conteúdo de matéria orgânica. Foram avaliados os fatores de erosão locais, tais como erosividade (R), erodibilidade (K), fator topográfico (LS), uso e manejo (C), práticas conservacionistas (P), potencial natural de erosão (PNE), perda de solo com e sem práticas conservacionistas (A e *A), tolerância de perda de solo (T) e risco de erosão (RE). As variáveis A, PNE e RE apresentaram forte correlação espacial com o fator topográfico (LS), indicando a forte relação do relevo sobre os fatores de erosão. As perdas de solo (A e *A) apresentaram comportamento coerente com a conceituação de superfícies geomórficas, evidenciando as relações de dependência do processo erosivo do solo aos ambientes geomórficos.

The objective of this research was to study the influence of the geomorphic surfaces in the spatial variations of the soil loss by erosion in the Pereira Barreto region, São Paulo State, Brazil. Soil samples were collected in 67 points, in a depth of 0.0-0.2m, located in a 350m regular grid to measure the particle size distribution and organic matter content. The local erosion factors were determined: erosivity (R), erodibility (K), topographical factor (LS), use and tillage (C), and conservation tillage (P), natural potential of erosion (PNE), soil loss with and without conservation tillage (A), soil loss tolerance (T) and erosion risk (RE). The variables A, PNE and RE presented great spatial correlation with the topographical factor (LS), indicating the influence of the relief on the erosion factors. The soil losses (A and A *) presented coherent behavior with the concept of geomorphic surfaces, evidencing the dependence relationships of the soil erosion process to the geomorphic environmental.

Variabilidade espacial de atributos químicos em latossolo e argissolos / Spatial variability of chemical attributes in latosol and argisol

O trabalho teve como objetivo caracterizar a variabilidade espacial de atributos químicos de Latossolos e Argissolos, sob cultivo de cana-de-açúcar em áreas com variações na forma do relevo. No presente estudo utilizou-se duas áreas, sendo uma em Latossolo em pedoforma convexa (158ha) e a outra em Argissolo na pedoforma linear (172ha). Foi coletada amostra de solo em malha na profundidade de 0,00-0,50m, realizando-se análise química de cada ponto amostrado. Os maiores coeficientes de variação e alcances foram observados na pedoforma convexa (Latossolo). Portanto, o Latossolo inserido na pedoforma convexa apresentou maior variabilidade espacial para os atributos químicos em relação ao Argissolo na pedoforma linear. O latossolo inserido pedoforma convexa necessita de maior número de pontos de coleta por apresentar maior variabilidade espacial. Recomenda-se que o intervalo de amostragem seja igual ao alcance da dependência espacial, para associar menor esforço de amostragem com maior representatividade.

The objective of this research was to characterize the spatial variability of chemical attributes of soils cultivated with sugarcane in areas with variations in relief forms. The two soils studied were a Latosol, placed in a convex landform (158ha), and an Argisol, placed in a linear landform (172ha). Soil samples for chemical analysis were collected in a regular grid, at the depth of 0.0-0.5m. The convex landform presented the highest coefficient variation and ranges. Therefore, the Latosol inserted in the landform convex presented greater spatial variability for chemical attributes than the Argisol in the linear landform. A larger number of points must be sampled in order to represent the spatial variability of the Latosol from the convex landform. We recommend the sampling interval to be equal to the range of the spatial dependency in order to associate a less intensive sampling effort with a higher representativity.