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Overland flow occurs on a land surface, making a sheet flow without any flow concentration. Under these conditions, cultivated semi-arid hillslopes experience inter-rill erosion. One objective of t...

CARACTERÍSTICAS ESTRUTURAIS E ACÚMULO DE FITOMASSA DO MILHETO SOB DIFERENTES REGIMES DE IRRIGAÇÃO COM ÁGUA RESIDUÁRIA E ADUBAÇÃO ORGÂNICA JOSÉ RALIUSON INÁCIO SILVA1; EDUARDO SOUZA1; MAURÍCIO LUIZ DE MELLO VIEIRA LEITE1; GENIVAL BARROS JUNIOR1; JOSE ROMUALDO DE SOUSA LIMA2 E ALDO TORRES SALES1 1Universidade Federal Rural de Pernambuco, Unidade Acadêmica de Serra Talhada, Programa de Pós-Graduação em Produção Vegetal, Avenida Gregório Ferraz Nogueira, s/n, José Tomé de Souza Ramos – CEP: 56909-535, Serra Talhada –PE, Brasil, raliuson.silva@ufrpe.br, eduardo.ssouza@ufrpe.br, mauricio.leite@ufrpe.br, genival.barrosjunior@ufrpe.br, aldo.torres@ufpe.br 2Universidade Federal do Agreste de Pernambuco, Avenida Bom Pastor, s/n, Boa Vista – CEP:55292-270, Granhuns-PE, romualdo.lima@ufape.edu.br 1 RESUMO A utilização de água residuária pode aumentar a oferta hídrica e de alimentos em regiões semiáridas. Assim, objetivou-se estudar a dinâmica temporal das características estruturais e acúmulo de fitomassa do milheto irrigado com diferentes lâminas de água cinza, com e sem adubação orgânica. A pesquisa foi conduzida em ambiente protegido em esquema fatorial (4 x 2) + 1, com três repetições, sendo os fatores: níveis de água disponível do solo (25, 50, 75 e 100%) e doses de esterco (0 e 34 Mg ha-1), mais o tratamento controle (irrigação com água potável e sem adubação). Foram realizadas avaliações semanais das características estruturais: comprimento e diâmetro do colmo e número de perfilhos, folhas totais, folhas vivas e folhas mortas, sendo ajustados modelos matemáticos para descrever o comportamento dessas características ao longo do ciclo da cultura. Após 60 dias de aplicação dos tratamentos o milheto foi colhido e determinou-se o acúmulo de fitomassa e massa de raízes. O modelo sigmoidal é o que melhor explica a dinâmica da maioria das características estruturais. A irrigação com águas cinzas não afetou as características estruturais, massa de raízes e o acúmulo de fitomassa do milheto, sendo indicado adubação a fim de melhorar o seu desempenho. Palavras-chave: Pennisetum glaucum, águas cinzas, dinâmica do crescimento, manejo de irrigação SILVA, J. R. I.; SOUZA, E.; LEITE, M. L. M. V.; BARROS JUNIOR, G.; LIMA, J. R. S; SALES, A. T. STRUCTURAL CHARACTERISTICS AND PHYTOMASS ACCUMULATION OF MILLET UNDER DIFFERENT IRRIGATION REGIMES WITH WASTEWATER AND ORGANIC FERTILIZATION 2 ABSTRACT The use of wastewater can increase the water and food supply in semi-arid regions. Thus, the objective was to study the temporal dynamics of structural characteristics and the accumulation of phytomass in millet irrigated with different depths of greywater, with and without organic fertilization. The research was conducted under greenhouse conditions in a factorial scheme (4 x 2) + 1 with three replications, the factors being levels of water available from the soil (25, 50, 75 and 100%) and manure doses (0 and 34 Mg ha-1), plus control treatment (irrigation with drinking water and without fertilization). It was performed weekly evaluations of structural characteristics: stem length and diameter, and number of tillers, total leaves, live leaves and dead leaves. Mathematical models were adjusted to describe the behavior of these characteristics throughout the cycle. After 60 days of the application of the treatments, millet was harvested and the accumulation of phytomass and root mass was determined. The sigmoidal model best explains the dynamics of most structural features. The irrigation with greywaters did not affect the structural characteristics, root mass and phytomass accumulation of millet, and fertilization is indicated to improve its performance. Keywords: Pennisetum glaucum, greywaters, growth dynamics, irrigation management

Biochar is a product rich in carbon, which improve the soil attributes and crop yield. In the Brazilian tropical dry region, common bean is cultivated under rainfed, in poor, acidic, and with low w...

The resistance induction becomes an alternative to control microorganisms that attacks like plants. Little is known about the dose and its effect on the enzymatic activities associated with the induction of resistance of pepper plants under anthracnose attack. The objective of this study was to evaluate the severity and to estimate the enzymatic activity of Arcade F1 hybrid peppers infected with Colletotrichum gloeosporioides and submitted to different doses of the abiotic acibenzolar-S-methyl inducer. The experimental design was completely randomized blocks with five treatments, four doses of acibenzolar-S-methyl (0.15, 0.30, 0.45 and 0.60 g.L-1), and the control with distilled water only. The evaluation of leaf severity and collection for enzymatic activity of β-1,3-glucanase, catalase, peroxidase, polyphenoloxidase and ascorbate peroxidase were performed on the 4th, 8th and 12th day after inoculation of the phytopathogen. The application of acibenzolar-S-methyl provided a reduction in anthracnose severity, with an increase in all the enzymatic activities evaluated, but there was no prevalence of a specific dose. However, all doses of the evaluated inducers were able to delay the development of the phytopathogen with elevated activity of one or more antioxidant enzyme. KEYWORDS: Antioxidant enzymes, phytopathogenic fungus, Colletotrichum gloeosporioides. RESUMO: A indução de resistência torna-se uma alternativa para controlar microrganismos que atacam as plantas. Pouco se sabe sobre a dose e seu efeito nas atividades enzimáticas associadas à indução de resistência de plantas de pimentão ao ataque da antracnose. O objetivo deste estudo foi avaliar a severidade e estimar a atividade enzimática de pimentões híbridos Arcade F1 infectados com Colletotrichum gloeosporioides e submetidas a diferentes doses do indutor abiótico acibenzolar-S-metil. O delineamento experimental foi em blocos inteiramente casualizados com cinco tratamentos, quatro doses de acibenzolar-S-metil (0,15; 0,30; 0,45 e 0,60 g.L-1), sendo a testemunha apenas água destilada. A avaliação da severidade foliar e coleta quanto à atividade enzimática de β-1,3-glucanase, catalase, peroxidase, polifenoloxidase e ascorbato peroxidase foram realizadas no 4º, 8º e 12º dias após a inoculação do fitopatógeno. A aplicação de acibenzolar-S-metil proporcionou redução da severidade da antracnose, com aumento de todas as atividades enzimáticas avaliadas, mas não houve prevalência de dose específica. Porém, todas as doses dos indutores avaliados são capazes de retardar o desenvolvimento do fitopatógeno com elevada atividade de uma ou mais enzimas antioxidantes. PALAVRAS-CHAVE: Enzimas antioxidantes, Fungos fitopatógenos, Colletotrichum gloeosporioides.

The effects of coffee biochar residue combined with cow manure fertilizer on soil chemical attributes, microbial biomass, and structure and abundance of the soil microbial community are not fully understood. Thus, the objective of this study was to evaluate the effect of coffee biochar combined with cow manure on chemical and microbial attributes in soil cultivated with bean (Phaseolus vulgaris). We hypothesized that biochar from coffee residues drives the bacteria, fungi, and diazotrophic communities in a sandy soil and increases the abundance of these microorganism groups, raising soil basal respiration and microbial biomass. The experiment was carried out in a completely randomized design and was distributed in a factorial scheme (2 × 3 + 2) including two types of biochar (coffee ground-CG and coffee husk-CH) at three dosages (4, 8, and 16 t ha−1), and two control groups (S = native soil without treatment (−control) and E = fertilization with cow manure at dosage of 15 m3 ha−1 (+control)). The experiments were conducted with four repetitions. All treatments received the same dosage of cow manure applied in sandy soil and bean seeds were grown in pots. Soil samples were collected after 45 days to evaluate chemical attributes, total organic carbon (TOC), microbial biomass (C, N, and P), soil basal respiration, structure and abundance of total bacterial and fungal community (16S rRNA, 18S rRNA) and diazotrophs (nifH) in the soil by DGGE (denaturing gradient gel electrophoresis) and qPCR (real-time quantitative PCR), respectively. The results showed that TOC increased 9 and 11.5% with highest dosage of CG and CH biochar, respectively; thus, CG at 4 t ha−1 increased the C:N ratio in soil (4.7 times). The addition of biochar combined with cow manure increased soil basal respiration in CG at 16 t ha−1. The combined application of CH at 16 t ha−1 and cow manure increased the P content (2.37 times) and K+ (5.6 times). The highest increase in C from microbial biomass was found in CG at 16 t ha−1 and the addition of biochar and cow manure did not affect the P content in microbial biomass; nevertheless, biochar increased the nifH gene abundance by 8.23% at 16 t ha−1. Biochar addition influenced the structure of soil microbial communities, presenting distinct and well-differentiated communities in the multivariate analysis, according to the dosage and type of biochar. The group formed by different CG dosages showed a higher number of 16S genes, and greater amounts of Nmic, nifH, soil basal respiration, metabolic quotient, K, and Na. The major conclusion of this study was that coffee biochar, used in combination with cow manure, significantly improves the chemical and microbiological attributes of sandy soil cultivated with bean.

Ecossistemas de regiões semiáridas, como a Caatinga, estão sendo afetados pelas mudanças climáticas globais, causando alterações na evapotranspiração (ET) e nos fluxos de CO2. Desse modo, o trabalho objetivou quantificar os fluxos de CO2 e ET, com o intuito de observar se a Caatinga atua como fonte ou como sumidouro de CO2. As medidas foram realizadas numa área de Caatinga, durante um período de 13 meses, no município de São João/PE, utilizando-se a metodologia da correlação dos turbilhões, com um analisador de CO2 e H2O e um anemômetro sônico tridimensional. Além disso, foi medida a umidade do solo nas profundidades de 10 a 50 cm. A ET variou de 0,4 a 4,7 mm d-1, com uma média de 2,33 mm d-1 e total de 933 mm. A ET também seguiu as variações da precipitação pluvial, com os valores mais elevados no período úmido e os menores, no período seco, possivelmente devido à baixa capacidade de retenção de água no solo. A variação do fluxo de CO2 na Caatinga indicou que a vegetação atuou ora como fonte e ora como sumidouro de carbono, com valores variando entre -4,89 e 6,87 μmol m-2 s-1. Entretanto, a Caatinga atuou, de maneira geral, como sumidouro de CO2, sequestrando, em média, 4,44 t C ha-1 ano-1. Desse modo, pode-se concluir que, nas condições edafoclimáticas do agreste pernambucano, a Caatinga atua sequestrando CO2 atmosférico, reforçando ainda mais a necessidade de preservação desse ecossistema.Palavras-chave: Caatinga; evapotranspiração; carbono; umidade do solo. Land Use Changes and Effects on the Water Balance Components in Agreste Pernambucano A B S T R A C TEcosystems in semi-arid regions, such as the Caatinga, are being affected by climate change, causing changes in evapotranspiration (ET) and CO2 fluxes. Thus, the work aimed to quantify the CO2 fluxes and ET, in order to observe whether the Caatinga acts as a source or a sink of CO2. The measurements were carried out in an area of Caatinga, during a period of 13 months, in the municipality of São João/PE, using the methodology of eddy covariance, with a CO2 and H2O analyzer and a three-dimensional sonic anemometer. In addition, soil moisture was measured at depths of 10 to 50 cm. The ET ranged from 0.4 to 4.7 mm d-1, with a mean of 2.3 mm d-1 and a total of 933 mm. The ET also followed the variations in rainfall, with the highest values in the wet season and the lowest in the dry season, possibly due to the low water retention capacity in the soil. The variation of the CO2 flux in the Caatinga indicated that the vegetation acted either as a source or as a sink of carbon, with values varying between -4.89 and 6.87 μmol m-2 s-1, being that the Caatinga acted, in general, as a CO2 sink, sequestering, on average, 4.44 t C ha-1 year-1. Thus, it can be concluded that, in the edaphoclimatic conditions of the Agreste of Pernambuco, the Caatinga acts by sequestering atmospheric CO2, further reinforcing the need to preserve this ecosystem.Key words: Caatinga; evapotranspiration; carbon; soil water content.

International audience; The current agricultural scenario faces a range of challenges, with phytosanitary ones being paramount. In most cases, plant diseases are treated with chemicals; however, they cause environmental pollution and face the acquired resistance of pathogens. Alternatively, biochar is a valuable tool for inducing the systemic resistance of plants since it is an effective and widely used resource to improve the physical, chemical, and biological attributes of the soil, consequently providing an adequate environment for healthy plant development. The effectiveness of the application of biochar in the control of plant diseases has been attributed to its alkaline pH, which contributes to the growth of beneficial microorganisms and increases the availability of nutrients, and to its porous structure, which provides a habitat and protection for the development of the soil microbiome. Therefore, the combined effect of improvements to soil attributes through biochar creates its role in controlling pathogens. This review assesses the beneficial and potential effects of biochar in agricultural soils, as well as showing the positive effects of biochar in the management of soil pathogens. Besides, we deeply evaluate twenty papers that used biochar as a strategy to manage plant diseases caused by pathogens inhabiting the soil in different soil-pathogen-plant systems. Among these studies, 70 % validate biochar as a strategy for the management of plant diseases; 10 % of studies showed that the efficiency of biochar as a disease management tool depends on the type of feedstock, and 20 % of studies describes that the biochar is not a management tool for suppressive diseases, caused by Pythium ultimum and Rhizoctonia solani in some host plants. The biochar is a strategy to manage plant diseases caused by pathogens inhabiting the soil, due different mechanisms as fungitoxic effect of biochar, sorption of allelopathic and phytotoxic compounds that can harm the plant, induction of plant resistance, increase of activities and abundance of beneficial microorganism’s, changes in soil quality as nutrient availability and abiotic conditions.

Land-use change has a significant influence on runoff process of any watershed, and the deepening of this theme is essential to assist decision making, within the scope of water resources management. The study was conducted for Mundaú River Basin (MRB) using the Soil and Water Assessment Tool (SWAT) model. The study aims to assess the issue of land-use change and its effect on evapotranspiration, surface runoff, and sediment yield. Input data like land use, topography, weather, and soil data features are required to undertake watershed simulation. Two scenarios of land use were analyzed over 30 years, which were: a regeneration scenario (referring to use in the year 1987) and another scene of degradation (relating to use in the year 2017). Land use maps for 1987 and 2017 were acquired from satellite images. Overall, during the last three decades, 76.4% of forest was lost in the MRB. The grazing land increased in 2017 at a few more than double the area that existed in 1987. Changes in land use, over the years, resulted in an increase of about 37% in the water yield of MRB. Changes have led to increased processes such as surface runoff and sediment yield and in the decrease of evapotranspiration. The spatial and temporal distribution of land use controls the water balance and sediment production in the MRB.

The search for better living conditions has led the residents of the Brazilian semi-arid region to plant forage crops, leading to a gradual decrease in the native vegetation (Caatinga) of this region. The effects caused by the replacement of Caatinga with palm, for example, have been little studied, especially with regard to the physical and hydraulic properties of the soil. The objective of this study was to compare the physical-hydraulic characteristics of a litholic neosol in two areas having different vegetation cover: one area cultivated with forage palm (O. ficus-indica) and the other covered by native Caatinga. Differences in soil structure, especially in porosity, between the natural and cultivated soils were observed to control the hydrodynamic processes, resulting in changes in water retention curves and hydraulic conductivity. Natural soil presents low values of hydraulic conductivity when compared to those of cultivated soil. This increase is probably due to soil management required for forage palm cultivation. The natural soil structure, characterized by relatively low saturated hydraulic conductivity values, presents an infiltrability that favors surface runoff. Human activities in the study area have promoted changes in the soil’s physical attributes, decreasing density and increasing porosity. Consequently, there is an increase in water infiltration into the soil and a reduction of runoff in cultivated areas, confirming results obtained in previous studies.

Phosphorus (P) plays a vital role in many aspects of plant growth and development. The low amount of available P in agricultural soils reduces crop productivity and phosphate fertilizers are often applied. However, due to the high affinity of P for the soil constituents, the availability of this element becomes limited to plants. Thus, alternative, ecological, and low-cost techniques have been studied to improve P acquisition by crops. Microorganisms able to solubilize P, mainly phosphate-solubilizing bacteria (PSB) have stood out, since they offer an approach to overcome P scarcity by their introduction in agricultural systems via inoculants. In this paper, we showed the potential of P-solubilizing microorganisms and their mechanisms of action, the potential of different inoculation vehicles, also highlighting the biochar as a viable biological product for production of inoculants. The combined effects of these factors (PSB and biochar) add several benefits to the soil-plant system. Results from this review demonstrate that biochar amendments have great potential as a vehicle for inoculation of PSB. However, studies of biochar combined with PSB is still incipient. Future research should focus efforts on exploring highly efficient strains, optimizing conditions, and assessing several sources of waste for production of biochar and their efficiency in field experiments. El fósforo (P) juega un papel vital en muchos aspectos del crecimiento y desarrollo de las plantas. La baja cantidad de P disponible en los suelos agrícolas reduce la productividad de los cultivos y a menudo se aplican fertilizantes fosfatados. Sin embargo, debido a la alta afinidad del P por los constituyentes del suelo, la disponibilidad de este elemento se limita a las plantas. Así, se han estudiado técnicas alternativas, ecológicas y de bajo costo para mejorar la adquisición de P por los cultivos. Se han destacado los microorganismos capaces de solubilizar P, principalmente bacterias solubilizadoras de fosfato (BSF), ya que ofrecen un enfoque para superar la escasez de P mediante su introducción en sistemas agrícolas a través de inoculantes. En este trabajo, mostramos el potencial de los microorganismos solubilizantes de P y sus mecanismos de acción, el potencial de diferentes vehículos de inoculación, destacando también el biocarbón como un producto biológico viable para la producción de inoculantes. Los efectos combinados de estos factores (BSF y biochar) agregan varios beneficios al sistema suelo-planta. Los resultados de esta revisión demuestran que las enmiendas de biocarbón tienen un gran potencial como vehículo para la inoculación de BSF. Sin embargo, los estudios de biocarbón combinado con PSB aún son incipientes. La investigación futura debe centrar los esfuerzos en explorar cepas altamente eficientes, optimizar las condiciones y evaluar varias fuentes de desechos para la producción de biocarbón y su eficiencia en experimentos de campo. O fósforo (P) desempenha um papel vital em muitos aspectos do crescimento e desenvolvimento das plantas. A baixa quantidade de P disponível em solos agrícolas reduz a produtividade da cultura e fertilizantes fosfatados são frequentemente aplicados. Porém, devido à alta afinidade do P pelos constituintes do solo, a disponibilidade desse elemento torna-se limitada às plantas. Assim, técnicas alternativas, ecológicas e de baixo custo tem sido estudadas para melhorar a aquisição de P pelas culturas. Microrganismos capazes de solubilizar P, principalmente bactérias solubilizadoras de fosfato (BSF), têm se destacado por oferecer uma abordagem para superar a escassez de P por meio de sua introdução em sistemas agrícolas via inoculantes. Neste trabalho, mostramos o potencial de microrganismos solubilizadores de P e seus mecanismos de ação, o potencial de diferentes veículos de inoculação, destacando também o biochar como um produto biológico viável para produção de inoculantes. Os efeitos combinados desses fatores (BSF e biochar) agregam vários benefícios ao sistema solo-planta. Os resultados desta revisão demonstram que os aditivos do biochar têm grande potencial como um veículo para inoculação de PSB. No entanto, estudos de biochar combinado com BSF ainda são incipientes. Pesquisas futuras devem concentrar esforços na exploração de cepas altamente eficientes, otimizando as condições e avaliando várias fontes de resíduos para a produção de biochar e sua eficiência em experimentos de campo.

Estudos com o LiDAR (Light Detection and Ranging) têm revelado precisão satisfatória nas medições da estrutura de árvores, o que tem contribuído para a compreensão dos ecossistemas florestais, bem como para o fornecimento de dados necessários para a investigação de propriedades biofísicas da floresta. Frente à importância dessa ferramenta, o presente estudo teve como objetivo apresentar uma revisão sobre o LiDAR direcionado para aplicações florestais, e especificamente apresentar suas possibilidades e uso na Caatinga. A varredura a laser tem diversas classificações, uma delas baseia-se na plataforma onde o scanner está instalado. Assim, tem-se o laser scanner terrestre, que pode ser usado em uma base fixa ou móvel na superfície terrestre; o laser scanner aéreo, com o uso de aeronaves tripuladas e não-tripuladas; e o laser scanner orbital, localizado em plataformas espaciais. Em escala refinada, a estrutura tridimensional das árvores pode ser detectada pelo LiDAR, e assim se obter importantes informações de traços de espécies vegetais, bem como permitir sua identificação. Ainda, a medição de atributos florestais promovida pelos diferentes tipos de LiDAR tem fornecido dados consistentes de biomassa e carbono florestais, importantes para o desenvolvimento de estudos e monitoramento de estoque de carbono terrestre, o que tem colaborado com as estratégias de redução de efeitos das mudanças climáticas. Na caatinga, o LiDAR tem permitido a contabilização de árvores e a determinação de sua altura e diâmetro da copa, e por conseguinte, a aplicação de equações alométricas para estimativa dos estoques de carbono na vegetação.Palavras-chave: TLS, ALS, UAV, LiDAR orbital, estrutura florestal, caatinga Use of LiDAR in Forest Data Estimation: A Review A B S T R A C TStudies with LiDAR (Light Detection and Ranging) have presented satisfactory accuracy on tree structure measurements, which has contributed to the understanding of forest ecosystems, as well as providing the necessary data for the investigation of biophysical properties of the forest. Given the importance of this tool, this study aimed to present a review of LiDAR for forestry applications, and specifically to present its possibilities and uses at the caatinga forest. Laser scanning has several classifications, one of which is based on the platform where the scanner is installed. Thus, there is the terrestrial laser scanner, which can be used on a fixed or mobile basis on the terrestrial surface; the aerial laser scanner, with the use of manned and unmanned aircraft; and the orbital laser scanner, located on space platforms. On a fine scale, the three-dimensional structure of trees can be detected by LiDAR, thus obtaining important information on plant traits, as well as allowing their identification. Furthermore, the measurement of forest attributes promoted by the different types of LiDAR has provided consistent data on forest biomass and carbon, important for the development of studies and monitoring of terrestrial carbon stock, which has collaborated with strategies to reduce the effects of changes climate. In the caatinga, LiDAR has allowed the counting of trees and the determination of their height and crown diameter, and, consequently, the application of allometric equations to estimate carbon stocks in the vegetation.Keywords: TLS, ALS, UAV, orbital LiDAR, forest structure, caatinga.

Many remote sensing-based evapotranspiration (RSBET) algorithms have been proposed in the past decades and evaluated using flux tower data, mainly over North America and Europe. Model evaluation across South America has been done locally or using only a single algorithm at a time. Here, we provide the first evaluation of multiple RSBET models, at a daily scale, across a wide variety of biomes, climate zones, and land uses in South America. We used meteorological data from 25 flux towers to force four RSBET models: Priestley–Taylor Jet Propulsion Laboratory (PT-JPL), Global Land Evaporation Amsterdam Model (GLEAM), Penman–Monteith Mu model (PM-MOD), and Penman–Monteith Nagler model (PME-VI). ET was predicted satisfactorily by all four models, with correlations consistently higher (R2 > 0.6) for GLEAM and PT-JPL, and PM-MOD and PM-VI presenting overall better responses in terms of percent bias (- 10

The municipality of Brejao has special conditions with cooler and rainy weather and deeper soils and well structured, with occurrence horizon latosols with the humic. So the aim of this study was to investigate the changes in chemical, physical and water attributes of the surface horizon of a humic Oxisol subjected to different forms of use in the South Agreste Pernambuco, and investigate the repellency of the soil water. The disturbed and undisturbed samples were collected in a native forest (MN), pasture 5 years (PA5) and grazing 30 (PA30) in three layers 0 to 10 cm, 10 to 20 cm and 20 to 30 cm and evaluated the chemical, physical and water attributes, and realized an infiltration test with simple ring. Chemical attributes presented typicality dystrophic yellow latosols, and attributes related to the acidity showing significant results mainly in the surface layer. Have the physical attributes that most change with inadequate management are the bulk density (Ds) and porosity. For the infiltration test it is clear the presence of soil water repellency.

International audience; Biochar is a material produced by the pyrolysis of agro-industrial waste, which has become one of the most promising management tools to improve soil quality. The aim was to determine the effects of incorporating biochar from different coffee wastes in sandy soil, cropped with maize, on soil chemical and microbial attributes. The experiment followed a factorial design 2 × 3 + 1 with two types of biochar, including coffee ground (CG) or coffee husk (CH) in 3 doses (4, 8, and 16 t·ha-1) and a control fertilized solely with bovine manure (3 t·ha-1). The variables analyzed were soil organic carbon, chemical attributes, microbial biomass (C, N and P), soil basal respiration and microbial gene abundance (16S rRNA, 18S rRNA and nifH gene). Most chemical attributes were strongly increased by CH application, while CG at 8 t·ha-1 increased the soil C:N ratio (3.5 times), P (2.1 times) and K+ (7.9 times) and at 4 t·ha-1 increased the C content, microbial biomass C and N (3, 2.1 and 1.6 times, respectively). The application of CG biochar at 16 t·ha-1 showed trend to increase the abundance of bacteria, fungi and diazotrophic genes (11, 10 and 2%, respectively). Contribution of both coffee biochar types, but mainly CH, was more effective than the soil that received organic manure alone. Biochar from coffee wastes is a promising tool to improve sandy soil quality.

International audience; The addition of biochar to the soil has been seen as a potential and low-cost important tool in the management of tomato diseases. Thus, the objective of this study was to evaluate the effect of biochar from different sources applied to the sandy soil against bacterial wilt disease caused by Ralstonia solanacearum in tomatoes. We set up two experiments: (1) To evaluate the impact of different sources of biochar: cassava husk (CHB), bean straw (BPB), sugar cane straw (SSB), and corn straw (CPB) in reducing the growth of the R. solanacearum in vitro; and (2) To evaluate the effect of the use of these biochars applied to the soil on reducing the severity of bacterial wilt in tomatoes. The different sources of biochar are efficient in reducing the formation of colony-forming units of R. solanacearum. CHB reduced the growth of the bacterium by 19%, followed by CPB and BPB, which showed an approximate reduction of 16% and 13%, respectively. Biochar BPB and CHB applied to the sandy soil were able to reduce the severity of bacterial wilt in tomatoes by 30%. Overall, our findings expand our knowledge about the reuse of wastes transformed in biochar that has potential perspective to formulate products as alternative management tool as management of bacterial wild (R. solanacearum) in tomato and add important information that can be suitable for development of strategy for use in the global health concept.

International audience; Pradoo wood biochar has been tested in order to explore sustainable solutions to the development of agriculture on poor sandy soils in marginal areas in Northeast Thailand. Some basic physicochemical properties of biochar, for example pore size distribution, cation exchange capacity (CEC), specific surface area (SSA), and water and nutrient adsorption, were determined and compared to soil properties in order to determine appropriate biochar application to soil. Pradoo wood biochar showed important adsorption properties with high SSA, CEC and nutrient adsorption. The water retention properties were also improved on the dry end of the water retention curve. Phosphorous and ammonium adsorption-desorption isotherms were established and their respective affinity for the biochar surface was quantified, by the means of a retention index and thermodynamical parameters. We found that despite excellent retention properties, biochar needs to be added in large amounts (between 10 and 70 kg m(-2)) to soil to be able to modify noticeably the resulting soil properties.

Soil respiration represents the largest flux of CO2 emission from terrestrial ecosystems, being affected by land-use changes and soil properties. There are few studies investigating the response of soil respiration to land-use changes in the Caatinga biome. This study aimed to measure soil respiration from Caatinga vegetation and degraded pasture, to verify the effect of land-use changes on soil respiration. Measurements of soil respiration were performed using the infrared gas analyzer method over nine months (in rainy and dry seasons), in Caatinga and degraded pasture in the semi-arid region of Pernambuco. The soil moisture, soil temperature, soil organic carbon (SOC), Normalized Difference Vegetation Index (NDVI), and climatic variables were also measured. Soil organic carbon and NDVI were higher in Caatinga than in degraded pasture, while the inverse occurred with soil temperature. The soil respiration showed a clear seasonal variation, with the highest values occurring in the wet season, being positively correlated with soil moisture and negatively with soil temperature. Soil respiration was significantly higher in the Caatinga (8.0 ton ha-1 yr-1 of C) than in degraded pasture (3.7 ton ha-1 yr-1 of C). These higher values of soil respiration in Caatinga were due to lower soil temperature and higher SOC, and can be seen as indicators of good environmental quality.

The textile industry generates a large volume of chemically diversified effluents containing, among other compounds, dyes. Untreated wastes are contaminants to surface water, soil, and groundwater. In this aspect, various studies have explored the issue of contamination of alluvial soils in the Alto Capibaribe region, northeast of Brazil, due to local textile activity. This region, inserted into the Brazilian semiarid region, suffers from water scarcity, and there is a need for rural communities to use alluvial formations for water supply. The simulation of solute transport is a fundamental tool for understanding the environmental performance and risks associated with contamination by textile dyes. Transport parameters that directly influence pollutant dynamics in sedimentary environments are characterized. This study evaluated the retention and mobility of the dye Remazol Black 5 (RB5) in two superficial layers of alluvial soil from Alto Capibaribe to obtain transport parameters. In the laboratory, tests of mobility in soil columns with RB5 dye (concentration of the 25 mg L−1) and KBr tracer (concentration of the 35.7 g L−1) solutions were conducted. The CDE and two-region models were used to model the KBr experimental transport data, and the two-site model was used to model the RB5 experimental transport data. Physical non-equilibrium was found in the soils for KBr transport, and the two-region model adequately modeled the experimental breakthrough curves (BTCs). For the transport of RB5, the results showed a chemical non-equilibrium, and the two-site model was adequate to model the experimental BTCs. The results indicate that the surface layer is most responsible for the retention of RB5, where the RB5 solution was less mobile than in the lower layer. Both layers showed low retention and high mobility for RB5, indicating that the RB5 dye in the region may contaminate groundwater.

O lodo de esgoto (LE) e um residuo solido, oriundo de Estacoes de Tratamentos de Esgoto (ETE), rico em materia orgânica, sendo capaz de melhorar as propriedades fisicas, quimicas e biologicas do solo. Contudo, o LE pode apresentar em sua composicao elementos toxicos e agentes patogenicos que trazem maleficios para saude humana e para o meio ambiente. A transformacao do LE, por meio do processo de pirolise, em biochar pode ser uma boa alternativa tanto do ponto de vista agricola, quanto do ambiental. Desse modo, o presente trabalho teve o objetivo de avaliar o efeito de biochar de lodo de esgoto (BLE) na eficiencia do uso da agua (EUA), na evapotranspiracao e na producao da cultura da alface. O experimento foi realizado em casa de vegetacao, no delineamento inteiramente casualizado, utilizando-se quatro tratamentos, consistindo de controle (sem biochar), BLE10 (10 t ha -1 de BLE), BLE20 (20 t ha -1 de BLE), BLE30 (30 t ha -1 de BLE), com tres repeticoes. Foram avaliadas a biomassa, a evapotranspiracao (ET) e a eficiencia no uso de agua (EUA) da alface. Nao foram observadas diferencas significativas na ET da alface com a adicao de BLE ao solo. Contudo, verificou-se que houve um aumento crescente da producao da alface e da EUA com o aumento das doses de BLE. Assim, o BLE mostrou-se uma interessante alternativa para uma destinacao adequada do lodo de esgoto gerado nas ETE. Sewage Sludge Biochar Increases Yield and Water Use Efficiency in Lettuce A B S T R A C T Sewage sludge (SS) is a solid residue, originating from Sewage Treatment Plants (STP), rich in organic matter, being able to improve the physical, chemical and biological properties of the soil. However, SS can present in its composition toxic elements and pathogenic agents that bring harm to human health and the environment. The transformation of SS, through the pyrolysis process, into biochar can be a good alternative both from an agricultural and environmental point of view. Thus, the present study aimed to evaluate the effect of sewage sludge biochar (SSB) on the water use efficiency (WUE) on evapotranspiration (ET) and on the yield of lettuce. The experiment was carried out in a greenhouse, in a completely randomized design, using four treatments, consisting of control (without SSB), SSB10 (10 t ha -1 of SSB), SSB20 (20 t ha -1 of SSB), SSB30 (30 t ha -1 SSB), with three repetitions. Fresh biomass, evapotranspiration (ET) and water use efficiency (WUE) of lettuce were evaluated. No significant differences were observed in the lettuce ET with the addition of SSB to the soil. However, it was found that there was an increase in the yield of lettuce and the WUE with increasing doses of SSB. Thus, the SSB proved to be an interesting alternative for an adequate destination of the sewage sludge generated in the STPs. Key words: Waste; evapotranspiration; carbon.

The use of biochar can bring benefits such as long-term carbon sequestration and water use efficiency, being an alternative for semiarid regions. The objective of this study was to evaluate the impact of the application of coffee biochar on sandy soil on maize growth, chemical, microbial and biochemical attributes in Entisol. The experimental design was completely randomized, distributed in a 2 x 4 + 1 factorial scheme, two types of wastes coffee ground (MCG) and coffee husks (MCH), four doses (4, 8, 12 and 16 Mg ha -1 ) and control (CONT), without biochar. All treatments received organic fertilization with manure. Coffee biochar applied to sandy soil cultivated with maize, as predicted, increased the total soil C content, mainly coffee husk biochar that increases twice the C content when compared to the control. Nutrient and some enzyme activities of soils were improved with increasing coffee biochar doses. Microbial biomass of soils amended with the biochars MCH16 and MCH12 showed an increase of 100 and 116%, respectively. This study demonstrated a clear response of the soil nutrients, microbial community and enzyme activities change to types and doses of biochar. However, the effects on the actual maize plant growth with these biochar treatments were not significative in the first cycle. Impacto do biochar de cafe sobre o carbono, biomassa microbiana e atividades enzimaticas de solo arenoso do semi-arido, cultivado com milho R E S U M O O uso do biochar pode trazer beneficios como o sequestro de carbono a longo prazo e a eficiencia do uso da agua, sendo uma alternativa para regioes semi-aridas. O objetivo deste estudo foi avaliar o impacto da aplicacao de biochar oriundos de residuos de cafe aplicado em solo arenoso sobre o crescimento de milho, atributos quimicos, microbianos e bioquimicos. O delineamento experimental utilizado foi inteiramente casualizado, distribuido em esquema fatorial 2 x 4 + 1, sendo dois tipos de residuos de cafe: borra (MCG) e casca de cafe (MCH), quatro doses (4, 8, 12 e 16 Mg ha -1 ) e controle (CONT), sem biochar. Todos os tratamentos receberam adubacao orgânica com esterco bovino. O biochar de cafe aplicado em solo arenoso cultivado com milho, conforme previsto, aumentou o teor total de C no solo, principalmente o biochar de casca de cafe, que aumentou em dobro do teor de C, comparado ao controle. Os teores de nutrientes e algumas atividades enzimaticas dos solos foram aumentados com o aumento das doses de biochar de cafe. Solos que receberam os tratamentos MCH16 e MCH12 aumentaram a biomassa microbiana em 100 e 116%, respectivamente. Este estudo demonstrou uma clara resposta dos nutrientes do solo, comunidade microbiana e atividades enzimaticas relativos aos tipos e doses de biochar. Por isso, recomenda-se o uso do biochar de cafe para o aumento da qualidade de solos arenosos no semi-arido brasileiro. Palavras-chave: Zea mays , enzima extracelular do solo, carbono orgânico total, biomassa microbiana do solo.

Wastewater from textile industries is loaded with synthetic dyes. These effluents are often not adequately treated, affecting the soil and groundwater quality and leading to environmental contamination. The Agreste mesoregion of the state of Pernambuco is home to one of the largest textile centers in Brazil. This work therefore aims to study the behavior of Remazol Black B (RB5) dye in subsurface mediums in this region. The kinetics and isotherm sorption experiments allowed an evaluation of RB5 retention capacity in two layers of alluvial soil of the dry riverbed of the Capibaribe Basin. The maximum sorption rate was 81.81 mg kg-1 and 21.7 mg kg-1 for the loamy sand and sand layers, respectively. The Pseudo-second order kinetic model described more appropriately the sorption kinetics for both soils. The isotherms behavior was nonlinear, and Freundlich model was the most suitable to describe this process for both soils, presenting KF values of 8.6407 L kg-1 for loamy sand and 0.1868 L kg-1 for sand. The isotherm parameters confirm a more significant interaction of RB5 with the loamy sand layer than with the sand layer, indicating lower leaching in the first layer, which is less mobile for RB5 contamination. Furthermore, the different sorption rates for both soils indicate the importance of studying the soil as a heterogeneous profile. Resumo As águas residuais das indústrias têxteis são carregadas com corantes sintéticos. Esses efluentes geralmente não são tratados adequadamente, afetando a qualidade do solo e das águas subterrâneas, levando à contaminação ambiental. O Agreste de Pernambucano abriga um dos maiores centros têxteis do Brasil. Portanto, este trabalho tem como objetivo estudar o comportamento do corante Remazol Black B (RB5) em meios subsuperficiais nessa região. Os experimentos de cinética e sorção isotérmica permitiram avaliar a capacidade de retenção do RB5 em duas camadas de solo aluvial do leito seco do rio Capibaribe. A taxa máxima de sorção foi de 81,81 mg kg-1 e 21,7 mg kg-1 para a camada areia franco e camada areia, respectivamente. O modelo cinético de pseudo-segunda ordem descreveu mais adequadamente a cinética de sorção para ambos os solos. O comportamento das isotermas foi não-linear e o modelo de Freundlich foi o mais adequado para descrever esse processo para ambos os solos, apresentando valores de KF de 8,6407 L kg-1 para areia franco e 0,1868 L kg-1 para areia. Os parâmetros isotérmicos confirmam uma interação mais significativa do RB5 com a camada de areia franco do que com a camada de areia, indicando menor lixiviação na primeira camada, menos móvel para a contaminação por RB5. Além disso, as diferentes taxas de sorção para os dois solos indicam a importância do estudo do solo como um perfil heterogêneo.

International audience; The Brazilian dry forest occupies an area of about 1 million km2 approximately 46% of which has been deforested. Many studies have been done on the effects of this on productivity and soil chemical attributes. However, little is known about soil enzymatic activity, which is sensitive to environmental changes. The objective of this study was to evaluate the effects of deforestation using different levels of human disturbance on soil enzyme activities, organic carbon content, microbial biomass, and microbial community. We studied areas covered with forest (TDF), old grass (OG), or new grass (NG). Soils from NG had increased microorganisms, which restored important processes related to carbon, sulfur, and nitrogen cycling, so that they resembled those in the forested area. The results of this study showed that the conversion of forest to pasture with a high level of human disturbance could decrease the activities of β-glucosidase, urease, alkaline phosphatase, and fluorescein diacetate in the soil by up to 87%, 66%, 62%, and 58%, respectively. These findings suggest that human disturbance can cause substantial changes in the enzymatic activity and microbial community in the soil. We suggest that maintaining grass pasture with low human disturbance should have fewer impacts on soil quality.

Biochar has been used to reuse the agro-industrial wastes and improve soil quality. Several studies have been carried out to show the impact of biochar on physical and chemical soil attributes. However, there are still gaps regarding the effects on as microbial biomass and enzymatic activities that are important to determine sensitive indicators to evaluate changes in management practices. The objective of this study was to assess the effect of two biochars on the chemical, microbial biomass carbon, and the enzymatic activities in an Entisol cultivated with bean. We evaluate two types of coffee biochar: ground and husks, four doses (4, 8, 12, and 16 Mg ha-1) and control. All treatments received organic fertilization with cow manure. Husks biochar increase the soil pH, Ca, and K, also contributing to the reduction of toxic aluminum contents and raising the concentrations of P labile. The treatments that received ground biochar showed higher soil organic carbon, microbial biomass, β-glucosidase, and fluorescein diacetate. Biochar produced from coffee residues increased sandy soil quality. We showed the first report on the beneficial impact of coffee biochar on enzymatic and microbiological quality of sandy soil cultivated with the bean.

The melon belongs to the family of commercially important cucurbitaceous in the world. However, the production of this crop can be very problematic in some places due to management practices and the climatic instability. Amongst the different options available to overcome these obstacles, the use of biochar often promoted for providing multiple benefits to crops, could contribute in holding more water and nutrients in soil and therefore improve the plant growth. A second way to try to improve the plant development was to use Trichoderma (TRI) known as aiding in seed germination, and being an excellent biological control agent against plant pathogenic pests. So, the objective of this study was to evaluate the benefits of the association of biochar and TRI on the initial growth of melon and the effects on the quality of a sandy Entisol. We quantified the effects of these associations through biometric growth in melon plants and chemical, microbial, and enzymatic activities of the biogeochemical cycles in the soil. An experiment in a completely of randomized design was performed in a factorial scheme (3 x 2 + 1) with three sources of biochar (bean husk (BH), coffee ground (CG), and coffee husk (CH)) inoculated with (T+) or without (T-) TRI and additional controls When the coffee grounds (CG) and bean husks (BH) biochar with T+ soil was inoculated, the fresh weight (number of leaves), dry weight, length (of roots and branch), soil acid and alkaline phosphatase, total organic carbon, phosphorus, magnesium, potassium, and pH were all increased. Moreover, T. aureoviride inoculated CG biochar compared to the control increased the shoot length and dry biomass of the melon plant in 30 and 22% between 22 and 30 %. The soil that received coffee husks (CH) biochar and T+ showed higher microbial biomass carbon. However, the melon plants responded more to the type of biochar than to the T. aureoviride inoculation, possibly due to the short growth time of melon. Results of BH biochar inoculated with T. aureviride in sandy soil showed improved efficiency on melon growth and increased soil quality.

The Caatinga is a typical seasonally dry forest with a fine-tuned adaptation to the climatic conditions of the Brazilian semi-arid region and has been frequently replaced by grassland. As the effects of this replacement on CO 2 , water and energy fluxes are still unknown, simultaneous measurements of such fluxes are essential to understand the possible feedback cycles associated with the seasonal functioning of these ecosystems, and assessing the consequences of global changes. The aim of this study was to measure the CO 2 , water and energy fluxes in the Caatinga and grassland in the semi-arid region of Brazil. The measurements were made using the eddy covariance method in Pernambuco State, Brazil. The soil storage water (SSW) and normalized difference vegetation index (NDVI) were also determined. The sensible heat flux (H) was the main consumer of the available energy and was higher in the grassland. Based on an analysis of the decoupling factor, in the dry season evapotranspiration (ET) was controlled by vegetation, and it was controlled by atmospheric conditions in the wet season. ET over the Caatinga (1.4 mm d −1 ) was higher than over the grassland (0.8 mm d −1 ). The Caatinga and grassland acted as atmospheric carbon sources during drier periods with lower NDVI, and as carbon sinks during wetter periods with higher NDVI. During the dry season, the Caatinga stored more carbon than the grassland, while the inverse occurred in the wet season. Thus, land use change from Caatinga to grassland will tend to increase H and to decrease ET, but the CO 2 fluxes will be similar.

Soil heat flux (G) is an important component for the closure of the surface energy balance (SEB) and the estimation of evapotranspiration (ET) by remote sensing algorithms. Over the last decades, efforts have been focused on parameterizing empirical models for G prediction, based on biophysical parameters estimated by remote sensing. However, due to the existing models’ empirical nature and the restricted conditions in which they were developed, using these models in large-scale applications may lead to significant errors. Thus, the objective of this study was to assess the ability of the artificial neural network (ANN) to predict mid-morning G using extensive remote sensing and meteorological reanalysis data over a broad range of climates and land covers in South America. Surface temperature (Ts), albedo (α), and enhanced vegetation index (EVI), obtained from a moderate resolution imaging spectroradiometer (MODIS), and net radiation (Rn) from the global land data assimilation system 2.1 (GLDAS 2.1) product, were used as inputs. The ANN’s predictions were validated against measurements obtained by 23 flux towers over multiple land cover types in South America, and their performance was compared to that of existing and commonly used models. The Jackson et al. (1987) and Bastiaanssen (1995) G prediction models were calibrated using the flux tower data for quadratic errors minimization. The ANN outperformed existing models, with mean absolute error (MAE) reductions of 43% and 36%, respectively. Additionally, the inclusion of land cover information as an input in the ANN reduced MAE by 22%. This study indicates that the ANN’s structure is more suited for large-scale G prediction than existing models, which can potentially refine SEB fluxes and ET estimates in South America.

Estudos voltados ao entendimento dos processos hidrológicos são de suma importância para auxiliar a gestão e a tomada de decisões relacionadas aos recursos hídricos. Modelos hidrológicos são considerados ferramentas poderosas no entendimento desses processos. Entretanto, tais modelos requerem uma série de dados que não estão facilmente acessíveis. Objetivou-se com este trabalho, aplicar e testar o modelo SWAT, seguindo uma sequência de procedimentos recomendada em uma sub-bacia do rio Mundaú, Nordeste do Brasil. Foram utilizados dados de entrada como mapa de uso e ocupação do solo, mapa digital de elevação e mapa dos tipos de solo, além de um período de 2000 a 2016, em passo de tempo diário. A acurácia do modelo foi medida com base no coeficiente de Nash-Sutcliffe (CNS), pelo percentual de tendência (PBIAS) e pelo coeficiente de determinação (R²). Os valores de CNS, PBIAS e R² obtidos foram de 0,53; -7,1 e 0,56 respectivamente, para o período de calibração. Foi possível realizar a modelagem hidrológica com o modelo SWAT na sub-bacia do rio Mundaú, obtendo-se desempenho satisfatório, segundo o CNS e muito bom considerando o PBIAS na calibração. Com o modelo calibrado, estudos futuros podem ser realizados com o SWAT, a fim de validá-lo e prever possíveis impactos de mudanças climáticas e de uso do solo na bacia estudada. Estudos como este têm mostrado que cada vez mais, os dados experimentais são imprescindíveis para a adequada representação e entendimento dos processos por meio da modelagem hidrológica.

Um modelo numérico foi utilizado para modelar a evapotranspiração do feijão caupi, e a evolução do estoque de água no solo nas profundidades de 10, 20 e 30 cm, utilizando dados de evapotranspiração potencial, precipitação e os seguintes dados hídricos: umidade volumétrica inicial, curva de retenção da água no solo e quatro valores de potenciais matriciais que regulam a extração de água pelas raízes. Os valores modelados de evapotranspiração foram comparados com os valores medidos pelo método do balanço de energia – razão de Bowen. A modelagem da evolução do estoque de água no solo foi comparada com dados medidos por uma sonda de nêutrons. Os valores médios de evapotranspiração da cultura foram 3,88 mm d 1 e 3,96 mm d-1, obtidos pelo modelo e pelo método do balanço de energia, respectivamente. O modelo predisse a evapotranspiração acumulada com um erro relativo subestimado de 1,77%. As evoluções dos estoques de água no solo nas profundidades de 10, 20 e 30 cm obtiveram resultados que apresentaram valores da raiz quadrada média do erro (RMSE) de 4,9, 6,3 e 10,5, respectivamente, o que indicam o pequeno espalhamento entre os dados medidos e os simulados.

Natural regeneration may be a cost-effective method for recovering areas previously used for intensive agricultural purposes. Plant diversity in the succession periods has been well documented; however, less attention has been paid to the changes in soil attributes, which may work as an instrument for the validation of regeneration methods. The present study is part of a broader interdisciplinary research project assessing the effects of natural regeneration on biodiversity and the quality of the soil. We investigated the effects of natural regeneration on the physicochemical attributes of the soil, as well as on soil organic carbon (SOC), microbial biomass carbon (MBC) and enzyme attributes. We assessed three stages and five areas of each natural regeneration stage (early-ER, intermediate-IR and late-LR) in two layers: 0–5 and 5–10 cm. The present study found a 20% SOC increase due to natural regeneration. In the first layer, SOC, urease, acid phosphatase and arylsulfatase absolute activities were significantly higher in the two older natural regeneration stages (IR and LR) than those found in the ER stage. We found a reduction in specific enzyme activities per SOC unit in the ER areas. Natural regeneration influenced SOC and MBC, the absolute enzyme activities, and the specific enzymes per SOC unit, mainly in the surface layer. The present study provided some of the first data concerning the beneficial effects of natural regeneration on the quality of soil as measured through enzyme activity, SOC and MBC in a tropical dry region in Northeastern Brazil.

O modelo Soil and Water Assessment Tool (SWAT) tem sido amplamente utilizado como ferramenta de simulação hidrometeorológica e de qualidade da água, sendo que o mesmo é extremamente sensível a diversos parâmetros. Assim, é importante definir os mais influentes e mais relevantes sobre o modelo, para reduzir as incertezas e melhorar os resultados gerados. O objetivo deste trabalho consiste em avaliar os parâmetros do modelo SWAT aplicado a uma sub bacia do Rio Mundaú. Foram selecionados 19 parâmetros relacionados aos processos de escoamento, solo, cultura, evapotranspiração e percolação e realizadas análises de sensibilidade global e local. De acordo com a análise global, os quatro parâmetros mais sensíveis do SWAT foram: a curva-número (CN) - CN2.mgt, o coeficiente de percolação - RCHRG_DP.gw, a profundidade do solo SOL_Z.sol e o coeficiente de Manning - OV_N.hru, com valores de t-stat de 4,28; 3,38; 2,44; 2,35; e p-value de 0,0004; 0,003; 0,02; 0,03, respectivamente. A partir da análise local, pode-se identificar os parâmetros mais sensíveis como sendo o CN2.mgt, o tempo para a recarga do aquífero - GW_DELAY.gw, o coeficiente de Manning - CH_N2.rte e o fator de compensação do consumo de água pelas plantas - EPCO.hru. Os parâmetros mais sensíveis para a sub-bacia do rio Mundaú foram aqueles relacionados com o escoamento superficial, fluxos subterrâneos, parâmetros do solo e culturas. A partir da análise de sensibilidade, estudos futuros podem ser realizados com o objetivo de calibrar e validar o modelo SWAT para a sub-bacia estudada e então proceder a simulação de cenários diversos. A B S T R A C T The Soil and Water Assessment Tool (SWAT) model has been widely used as hydrometeorological and water quality simulation tool, and it is extremely sensitive to the various parameters. Thus, it is important to define the most influential and most relevant on the model, to reduce uncertainties and improve the generated results. The aim of this study is to evaluate the parameters of the SWAT model applied to a sub-basin of the Mundaú River. Nineteen parameters were selected related to flow processes, soil, culture, evapotranspiration and percolation and performed global and local sensitivity analyzes. According to the global analysis, the four most sensitive parameters of SWAT were: the curve-number (CN) - CN2.mgt, the percolation coefficient - RCHRG_DP.gw, the soil depth - SOL_Z.sol and Manning coefficient - OV_N.hru, with t-stat values of 4.28; 3.38; 2.44; 2.35 and p-value of 0.0004; 0.003; 0.02; 0.03, respectively. From the local analysis, the most sensitive parameters were identified as the CN2.mgt, the time for aquifer recharging - GW_DELAY.gw, Manning coefficient - CH_N2.rte and compensation factor and water consumption by plants - EPCO.hru. The most sensitive parameters of the SWAT model for the sub-basin of the Mundaú river were those related to surface runoff, groundwater flow, soil parameters and cultures. From the sensitivity analysis, future studies can be performed in order to calibrate and validate the SWAT model for the studied sub-basin and then proceed to simulate various scenarios. Keywords: hydrologic modeling, water resources, SWATCUP.