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Weeds are responsible for losses in sugarcane productivity, often requiring the application of herbicides to control their infestation in crops. One of the herbicides commonly used in sugarcane cultivation is Imazapic. However, this chemical can be leached into environmental compartments when applied to soil, contaminating it. Scientific research has shown that the soil amended with biochar can reduce the leaching of herbicides, avoiding environmental pollution. Therefore, the present work aimed to evaluate the adsorption efficiency of Imazapic in a dystrophic Yellow Ultisol amended with biochar cultivated with sugarcane. Biochars were produced with sugarcane bagasse by pyrolysis at temperatures of 300, 500, and 700ºC to evaluate the adsorption capacity of Imazapic by the soil amended with biochar. The experiments revealed an increase in Imazapic adsorption with soil amended with biochar and that the adsorptive potential is more significant for pyrolyzed biochars at higher temperatures. In this way, the biochars produced can reduce the risks of groundwater contamination by increasing the residence time of Imazapic in the surface layer of the soil, being subject to the action of microbial degradation and other forms of degradation.

Radiotherapy (RT) is an important treatment for cervical cancer. The quality of life of patients undergoing RT may be compromised during and following treatment by nausea, diarrhea, vomiting, burns, erythema and fistula. Cytokinesis-block micronucleus (CBMN) assays may be useful for predicting adverse effects of RT for cancer. The CBMN test is easy to perform and is reproducible for screening subjects exposed to ionizing radiation. We investigated the use of the frequency of micronuclei (MN) from peripheral blood samples, irradiated in vitro, as a possible biomarker to predict the side effects of RT in patients with cervical cancer. We used 10 patients with cervical cancer receiving RT and chemotherapy. We found a strong relation between the frequency of MN and the appearance of acute side effects of RT for cervical cancer. We suggest that the methodology presented here may be useful for predicting side effects of RT for patients affected by cervical cancer and who have undergone chemotherapy.

To model water flow and solute transport in soils, hydrodynamic and hydrodispersive parameters are required as input data in the mathematical models. This work aims to estimate the soil hydraulic and solute transport properties using a ponded axisymmetric infiltration experiment using a single-ring infiltrometer along with a conservative tracer (Cl-) in the field. Single ring infiltration experiments were accomplished on an Oxisol in Areia in the state of Paraíba, Brazil (6o 58' S, 35o 41' W, and 645 m), in a 50 x 50 m grid (16 points). The unsaturated hydraulic conductivity (K) and the sorptivity (S) were estimated for short or long time analysis of cumulative three-dimensional infiltration. The single tracer technique was used to calculate mobile water fraction (Ф) by measuring the solute concentration underneath the ring infiltrometer at the end of the infiltration. Two solute transfer numerical models based on the mobile-immobile water concept were used. The mobile water fraction (Ф), the dispersion coefficient (D), and the mass transfer coefficient (a) between mobile and immobile were estimated from both the measured infiltration depth and the Cl- concentration profile underneath the infiltrometer. The classical convection-dispersion (CD) and the mobile-immobile (MIM) models showed a good agreement between calculated and experimental values. However, the lowest standard errors to the fitted parameters were obtained by the CD model. Para modelar el flujo de agua y el transporte de solutos en los suelos, se requieren parámetros hidrodinámicos e hidrodispersivos como datos de entrada en los modelos matemáticos. Este trabajo tiene como objetivo estimar las propiedades hidráulicas y de transporte de solutos del suelo utilizando un experimento de infiltración simétrica de eje utilizando un infiltrómetro de anillo único junto con un trazador conservador (Cl-) en el campo. Se realizaron experimentos de infiltración de anillos simples en un Oxisol en Areia, en el estado de Paraíba, Brasil (6°58'S, 35°41'W y 645 m), en una cuadrícula de 50x50 m (16 puntos). La conductividad hidráulica insaturada (K), y los sorbidos (S), se estimaron analizando el tiempo largo y corto de la infiltración tridimensional acumulada. Se utilizó la técnica del trazador único para calcular la fracción de agua móvil, Ф, midiendo la concentración de soluto debajo del infiltrómetro de anillo al final de la infiltración. La fracción de agua móvil (Ф), el coeficiente de dispersión (D) y el coeficiente de transferencia de masa (a) entre agua móvil e inmóvil se estimaron a partir de la profundidad de infiltración medida y el perfil de concentración de Cl- debajo del infiltrómetro de anillo. Los modelos de convección-dispersión (CD) y móvil-inmóvil (MIM) lograron una buena concordancia entre los valores calculados y medidos. Sin embargo, los errores estándar más bajos para los parámetros ajustados se obtuvieron para el modelo de CD. Para modelar o fluxo de água e o transporte de solutos no solo, parâmetros hidrodinâmicos e hidrodispersivos são necessários como dados de entrada nos modelos matemáticos. Este trabalho tem como objetivo estimar as propriedades hidráulicas e de transporte de soluto do solo por meio de um experimento de infiltração axissimétrica utilizando um único anel como infiltrômetro juntamente com um traçador conservador (Cl-) em campo. Experimentos de infiltração em anel simples foram realizados em um Latossolo em Areia, Paraíba, Brasil (6°58'S, 35°41'W e 645 m), em uma malha de 50x50 m (16 pontos). A condutividade hidráulica insaturada (K), e a sorvidade (S), foram estimadas pelas análises dos tempos longo e curto da infiltração tridimensional cumulativa. A técnica de traçador único foi usada para calcular a fração de água móvel, Ф, medindo a concentração de soluto abaixo do infiltrômetro no final da infiltração. Dois modelos numéricos de transferência de soluto baseados no conceito de água móvel-imóvel foram usados. A fração de água móvel (Ф), o coeficiente de dispersão (D) e o coeficiente de transferência de massa (a) entre a água móvel-imóvel foram estimados a partir da profundidade de infiltração medida e do perfil de concentração de Cl- abaixo do infiltrômetro de anel. Os modelos de convecção-dispersão (CD) e móvel-imóvel (MIM) alcançaram uma boa concordância entre os valores calculados e medidos. No entanto, os menores erros padrão para os parâmetros ajustados foram obtidos para o modelo CD.

In sugarcane crops, several agricultural pesticides are applied simultaneously, and a set of these can be detected in groundwater and surface waters, characterizing a contamination by pesticides mixtures with different concentrations in these bodies of water. Thus, the aim of this work is to estimate the gray water footprint of the pesticide mixture (herbicides) used in a dystrophic Yellow Ultisol in a sugarcane cultivation system, in Pernambuco, Brazil, based on the toxicity of each pesticide used in the mixture. For this objective, the model proposed by Paraiba et al. (2014) was used, where the gray water footprint is determined by physicochemical characteristics of the soil and pesticides, the pesticide application rates (dose), and the lowest value of the effective mean dose of these substances in a population of organisms (EC50). The gray water footprint of the pesticide mixture was 1.32 × 105 m3 ha−1. The highest volumes of gray water and higher ranks of the mixture were due to Amicarbazone and Hexazinone, with 1.05 × 105 m3 ha−1 (r = 5) and 3.71 × 104 m3 ha−1 (r = 4.6), respectively, and the lowest values were due to Paraquat and Glyphosate, with gray water footprint of 1.64 and 8.43 m3 ha−1, respectively. The gray water footprint for the yield of the sugarcane crop was estimated at 1731.1 m3 t−1, considered a high value for the gray water footprint of the sugarcane, demonstrating how much this crop can demands water resources to dilute its load of contaminants.

The determination of the hydraulic and hydrodispersive properties of soil is necessary for the understanding of water dynamics and soil solute transport, and they are used as input data in several models. Determinations of soil hydraulic and hydrodispersive parameters are usually obtained by separate methodologies. Axisymmetric infiltration tests using a single ring infiltrometer with a conservative tracer (KBr) in the field (Beerkan-Solute) lead to the determination of the most realistic hydraulic and hydrodispersive properties of the study area. The objective of this work was the hydrodynamic and hydrodispersive characterization of an irrigated soil, classified as Fluvic Cambisol, from the lowland areas of the northeastern semi-arid region, located in the backwoods of the state of Pernambuco, in the municipality of Serra Talhada-PE. The hydrodispersive parameters were determined with the CXTFIT 2.0 program, using the CDE and MIM models. The studied soil presented hydrodynamic characteristics with high values of sorptivity (S) that were associated with high values of saturated hydraulic conductivity (Ks), indicating that the soil has good permeability and resistance to surface crumbling caused by rain drops or soil management. It was observed the predominance of the convective process, being the CDE model the one that presented the best performance in the transport of the KBr tracer under field conditions, indicating the absence of two water regions mobile and immobile in the studied soil. RESUMO A determinação das propriedades hidráulicas e hidrodispersivas do solo é necessária para o entendimento da dinâmica da água e do transporte de solutos no solo, sendo utilizadas como dado de entrada em diversos modelos. As determinações dos parâmetros hidráulicos e hidrodispersivos do solo são normalmente obtidas por metodologias separadas. A realização de ensaios de infiltração axissimétrica utilizando um infiltrômetro de anel simples com um traçador conservativo (KBr) em campo (Beerkan-Soluto) conduz a determinações das propriedades hidráulicas e hidrodispersivas mais realistas da área em estudo. Este trabalho teve como objetivo a caracterização hidrodinâmica e hidrodispersiva de um solo irrigado, classificado como Cambissolo Flúvico, em áreas de baixios da região do Semiárido nordestino, situado na microrregião do Sertão Pernambucano, no município de Serra Talhada-PE. As determinações dos parâmetros hidrodispersivos foram realizadas com o programa CXTFIT 2.0, com uso dos modelos CDE e MIM. O solo estudado apresentou característica hidrodinâmica retratada em altos valores de sorvidade (S) associados a altos valores de condutividade hidráulica saturada (Ks), indicando que o solo apresenta boa permeabilidade e resistência ao encrostamento superficial, provocado por gotas de chuva ou manejo do solo. Observou-se o predomínio do processo convectivo, sendo o modelo CDE o que apresentou melhor desempenho no transporte do traçador KBr em condições de campo, indicando a ausência de duas regiões água móvel e imóvel no solo estudado.

This research was designed to evaluate the influence of the irradiation process of the leaf extracts of Libidibia ferrea (Leguminosae) on the production of secondary chemical compounds, including their biological activity. Leaves were collected and prepared to obtain the crude extract, which was then aliquoted and separately exposed to a Co-60 source with different doses, namely: 5, 7, 10, 12, 15, 20, 25, and 30 kGy. From irradiated and control samples, tests of toxicity were carried out with the microcrustacea Artemia salina Leach at three moments: 24 h, 60 and 180 days after the irradiation of the samples. Bioassays showed an increase in the toxicity of the irradiated extracts, correlated with the dose. The toxicity level did not change with the storage time, indicating the excellent stability of the samples. To assess the phytochemical profile of the crude and irradiated extracts, three techniques were employed: thin-layer chromatography (TLC), liquid chromatography coupled to mass spectrometry (LC-MS), and gas chromatography coupled to mass spectrometry (GC-MS). The phytochemical results emphasized the presence of phenols, tannins, and triterpenes. The analytical tests confirmed the role of ionizing radiation in breaking down macromolecules into simpler chemical species responsible for increasing chemical activity of the extract. This report presents and discusses ionizing radiation as an outstanding tool for enhancing active chemical compounds in leaf extracts of Libidibia ferrea, which reflects on their biochemical properties.

O comportamento hidrodinâmico de solos em cultivo de vazante foi analisado por meio das curvas de retenção θ(h), da condutividade hidráulica K(h), da sorvidade S e do raio característico de poros λm, determinados em dois Neossolos Flúvicos das vazantes dos açudes Cajueiro e Flocos, em Tuparetama, PE. O solo de Cajueiro apresenta uma pequena transição de textura e de densidade do solo, já o de Flocos apresenta uma evidente transição dessas propriedades em profundidade. As curvas de θ(h) foram obtidas pelo ajuste da equação de van Genuchten aos valores de campo (por meio de medidas de tensiômetros e de sonda de nêutrons) e de laboratório (por meio da “câmara de pressão de Richards”). Para determinação de K e S, foram realizados ensaios com o infiltrômetro a disco (0,08 m diâmetro da base), com quatro tensões de fornecimentos, nas profundidades de 0, 0,20, 0,40, 0,60 e 0,80 m. As curvas de θ(h) mostraram boa concordância na faixa de potencial de -30 a -10 kPa, indicando coerência dos dados experimentais. A heterogeneidade hidrodinâmica do solo de Flocos é explicada pela textura e densidade do solo e em Cajueiro é induzida pela distribuição dos tamanhos dos poros. O diâmetro do infiltrômetro, combinado às tensões aplicadas, permitiu caracterizar a matriz porosa da camada argilosa do solo de Flocos.

The concept of gray water footprint (GWF) was introduced as an indicator of the volume of freshwater required to dilute the total pollutant load, generated from a particular production process, to maintain water quality standards. In crop production, for example, the theoretical calculation of the GWF can be employed as a sound tool for assessing the environmental impacts due to the use of pesticides. In this context, we compared two models for estimating the GWF of pesticide mixtures applied to the soil in a sugarcane crop, in Pernambuco, Brazil. One model was proposed by Hoekstra et al. (2011) and calculates the GWF based on the maximum concentration limit acceptable in water. The other one was designed by Paraiba et al. (2014) and employs the concept of Concentration Addition. This latter model also takes into account the effect of toxicity of pesticide mixtures on aquatic organisms and water quality, considering the characteristics of the soil and cultivation data obtained through the field and physical-chemical tests pesticides used in agricultural activities. The model of Paraiba et al. (2014) has shown to be more conservative in determining the GWF of the pesticide mixtures (2.00 × 107 m³ ha−1) in the aquatic ecosystem, than the model of Hoekstra et al. (2011) (6.25 × 105 m³ ha−1 for Sulfentrazone). The results presented and discussed in this study reinforce the use of the GWF as an indicator of water quality for agricultural sustainability. Our work also contributes to a better understanding of the advantages and limitations of each model approach in the assessment of the volume of freshwater needed to dilute the contaminant load in agriculture activities as, for instance, in sugarcane crops.

Vinasse is a byproduct of the process of distillation of sugarcane juice for the manufacture of sugar and alcohol. Because it is rich in nutrients, mainly potassium (K), is used as fertilizer and applied via fertigation, without concerning for the fate of this compound in the soil. Thus, the objective of the study was to evaluate the interactions of the potassium ion (K+), applied via vinasse in a soil representative of the sugarcane zone of the State of Pernambuco using adsorption isotherms. The methodology was based on physical, chemical and soil mineralogical characterization, as well as equilibrium batch tests, where the experimental curves were fitted by Langmuir and Freundlich isotherm models. The results allowed to infer that the Freundlich model showed better fit of the curve in both forms: linear and non-linear (direct fit); the non-linear model was selected due to the values ​​of coefficient of determination (R²). The interaction between potassium and soil occurred mainly with organic matter and the presence of soil kaolinite, because they showed negative ions on the external surface, thereby promoting potassium adsorption. Soil potassium adsorption capacity was higher for the first layer (0-20 cm) and decreased along the depth profile.

Modeling of water movement in non-saturated soil usually requires a large number of parameters and variables, such as initial soil water content, saturated water content and saturated hydraulic conductivity, which can be assessed relatively easily. Dimensional flow of water in the soil is usually modeled by a nonlinear partial differential equation, known as the Richards equation. Since this equation cannot be solved analytically in certain cases, one way to approach its solution is by numerical algorithms. The success of numerical models in describing the dynamics of water in the soil is closely related to the accuracy with which the water-physical parameters are determined. That has been a big challenge in the use of numerical models because these parameters are generally difficult to determine since they present great spatial variability in the soil. Therefore, it is necessary to develop and use methods that properly incorporate the uncertainties inherent to water displacement in soils. In this paper, a model based on fuzzy logic is used as an alternative to describe water flow in the vadose zone. This fuzzy model was developed to simulate the displacement of water in a non-vegetated crop soil during the period called the emergency phase. The principle of this model consists of a Mamdani fuzzy rule-based system in which the rules are based on the moisture content of adjacent soil layers. The performances of the results modeled by the fuzzy system were evaluated by the evolution of moisture profiles over time as compared to those obtained in the field. The results obtained through use of the fuzzy model provided satisfactory reproduction of soil moisture profiles. A modelagem do movimento da água na região não saturada do solo requer normalmente um grande número de parâmetros e variáveis, como a umidade volumétrica inicial, a umidade volumétrica saturada e a condutividade hidráulica saturada, que podem ser avaliadas de forma relativamente simples. O fluxo monodimensional da água nessa mesma região do solo é normalmente modelado por meio de uma equação diferencial parcial não linear, conhecida como a equação de Richards. Desde que essa equação não possa ser resolvida analiticamente em alguns casos especiais, uma maneira de aproximar sua solução é por meio de algoritmos numéricos. O sucesso dos modelos numéricos em descrever a dinâmica da água no solo está intimamente relacionado com a precisão com que os parâmetros físico-hídricos são determinados. Esse tem sido o grande desafio no uso dos modelos numéricos, pois, em geral, tais parâmetros são difíceis de determinar e apresentam grande variabilidade espacial no solo. Portanto, fazem-se necessários o desenvolvimento e a utilização de métodos que incorporem, de maneira apropriada, as incertezas intrínsecas ao deslocamento da água nos solos. Neste trabalho, um modelo com base na lógica fuzzy foi usado como solução alternativa para descrever o fluxo de água na zona não saturada do solo. Esse modelo fuzzy foi desenvolvido para simular o deslocamento da água em um solo cultivado ainda não vegetado, durante o período chamado fase de emergência. O princípio desse modelo consiste de um sistema com base em regras fuzzy do tipo Mamdani, em que as regas se baseiam no teor de umidade das camadas adjacentes do solo. O desempenho dos resultados modelados pelo sistema fuzzy foram avaliados pela evolução dos perfis de umidade, ao longo do tempo comparado com os obtidos em campo. Os resultados pelo uso do modelo fuzzy apresentaram uma reprodução satisfatória dos perfis de umidade volumétrica.

Para modelar o fluxo de água e o transporte de soluto em solos são necessários parâmetros hidrodinâmicos e hidrodispersivos como dados de entrada nos modelos numéricos. O experimento de infiltração axissimétrica utilizando um infiltrômetro de anel simples com um traçador conservativo (KCl) é um método simples e eficiente para determinar esses parâmetros no campo. O objetivo deste trabalho consistiu na caracterização hidrodinâmica e hidrodispersiva de um Latossolo Amarelo situado na microrregião do brejo paraibano, no município de Areia, PB, em nível de campo, por meio da infiltrometria de anel simples. Os experimentos foram realizados em uma área cultivada com feijão em uma malha de 50 x 50 m. A condutividade hidráulica saturada, Ks, e a sorvidade, S, foram estimadas pelas análises de infiltração tridimensional axissimétrica para tempos curto e longo. O soluto inerte (Cl-) foi utilizado para o cálculo da fração de água móvel, Φ, por meio da medição da concentração de soluto na camada do solo (0-15 cm) ao final do experimento de infiltração. Um modelo numérico de transferência de soluto com base no conceito de convecção-dispersão (CD) foi utilizado para definir os parâmetros (D e R) de transporte. A infiltrometria de anel simples demonstrou ser um método simples e eficiente para obtenção dos parâmetros hidrodinâmicos e hidrodispersivos. Observou-se boa concordância entre os valores medidos e calculados (v, D e R) com o modelo CD observado pelos coeficientes de determinação (r²). To model the water flow and solute transport in soils, hydrodynamic and hydrodispersive parameters are required as input data in the mathematical models. The axisymmetric infiltration experiment using a single-ring infiltrometer with a conservative tracer (KCl) is a simple and efficient method for the determination of these parameters in the field. The objective of this study was to characterize hydrodynamic and hydrodispersive parameters of some soils in a marshy region, in Areia-PB, in the field, based on single-ring infiltration tests. The experiments were conducted in an area with common bean, in a 50 x 50 m grid. Saturated hydraulic conductivity (Ks) and sorptivity (S) were estimated by analysis of three- dimensional axisymmetric infiltration for short and long periods. The inert solute (Cl-) was used to calculate the mobile water fraction Φ, by measuring solute concentration in the 0-15 cm layer at the end of the infiltration experiment. A numerical model of solute transfer based on the concept of convection-dispersion (CD) was used to determine the transport parameters (D and R). Single-ring infiltrometry proved to be a simple and efficient method to obtain the hydrodynamic and hydrodispersive parameters. A good agreement was observed between measured and calculated values (v, D and R) with the model CD, based on the coefficients of determination (r²).

Paclobutrazol is growth regulator of plants that has low mobility in soil and therefore has accumulated. The objective of this study was to investigate the paclobutrazol biodegradation in two soils from the São Francisco River Valley. The biodegradation experiments were conducted in batch using paclobutrazol and paclobutrazol added glycerol. The experiments were performed in sterile and nonsterile conditions using a mixed culture of Pseudomonas. The concentration of paclobutrazol was determined by high performance liquid chromatography. The biodegradation reached 43% in 14 days of experiments with only paclobutrazol and 70% in 28 days of experiments that contained glycerol and paclobutrazol.

O conhecimento das curvas de retenção e da condutividade hidráulica da água do solo é indispensável para a modelagem do transporte de água e de poluentes em sistemas agrícolas. Essas propriedades são afetadas por numerosas fontes de variabilidade, geralmente associadas a fatores espacial e temporal, e relacionadas com o manejo agrícola. O objetivo desse trabalho foi analisar a variabilidade espacial dos parâmetros das curvas de retenção da água (van Genuchten) e da condutividade hidráulica (Brooks & Corey) da água do solo, obtidos com o método "Beerkan", que se baseia em ensaios de infiltração simplificados e nas informações texturais do solo. Esses parâmetros são de forma ou texturais (parâmetros de ajuste que dão forma às curvas) e de normalização ou estruturais (umidade volumétrica saturada, condutividade hidráulica saturada do solo e potencial de entrada de ar). Os ensaios de campo foram conduzidos em uma malha regular de 25 x 25 m num Neossolo Flúvico e num Latossolo Amarelo cultivados com feijão (Vigna unguiculata (L.) Walp.). Para ambos os solos, os valores dos parâmetros de forma, da umidade volumétrica saturada, dos logaritmos da condutividade hidráulica saturada e do potencial de entrada de ar apresentaram dependência espacial. Os valores da umidade volumétrica saturada e dos logaritmos do potencial de entrada de ar foram mais sensíveis à variação a pouca distância no Neossolo Flúvico do que do Latossolo Amarelo, com semivariogramas apresentando estruturas de variação com fraca dependência espacial. Knowledge on soil hydraulic properties such as water retention and hydraulic conductivity curves is indispensable for water and pollutant transport modeling of agricultural systems. This soil hydraulic properties are affected by numerous sources of variability, mostly associated with spatial, temporal, and management-related factors. The objective of this study was to analyze the spatial variability of parameters of water retention (van Genuchten) and hydraulic conductivity (Brooks & Corey) curves obtained with the "Beerkan" method based on simple infiltration experiments and soil texture data. These parameters are related to shape or texture (fitting parameters that shape the curves) and normalization or structure (saturated water content, saturated hydraulic conductivity and air entry potential). The field tests were carried out in a 25 x 25 m grid in a Fluvent soil and in an Oxisoil planted with beans (Vigna Unguiculata (L.) Walp.). For both soils, spatial dependence was verified in the values of parameters of shape, saturated water content, logarithms of the saturated hydraulic conductivity and air entry potential. The values of saturated water content and air entry potential were more sensitive to variation at short distances in the Fluvent than in the Oxisoil. The spatial dependence in the variograms was weak.

O conhecimento das propriedades hidráulicas do solo, tais como as curvas de retenção da água no solo teta(h) e da condutividade hidráulica K(teta), é indispensável para a modelagem do transporte de água e de poluentes em sistemas agrícolas. Várias técnicas experimentais têm sido propostas para determinar essas características do solo diretamente no campo, porém a complexidade, os custos elevados e o tempo de execução dessas medidas, são fatores que limitam bastante a obtenção dessas informações em grande escala. Apresenta-se, no presente trabalho, uma metodologia conhecida como "Beerkan", com a qual se busca minimizar esses fatores utilizando-se dados experimentais de infiltração, da distribuição granulométrica e da massa específica do solo, para então se estimar os parâmetros das curvas de teta(h) e K(teta). O método foi aplicado em dois solos com diferentes classes texturais (três de um Latossolo Amarelo e três de um Neossolo Flúvico). Determinaram-se, com vistas à caracterização hidrodinâmica, os parâmetros de forma das curvas de teta(h) de van Genuchten e de K(teta) de Brooks e Corey, dependentes majoritariamente da textura do solo e obtidos a partir da curva de distribuição dos tamanhos das partículas, além dos parâmetros de normalização dependentes, essencialmente, da estrutura do solo e obtidos a partir dos ensaios de infiltração utilizando-se o infiltrômetro de anel simples. O método Beerkan provou ser robusto e adaptado à caracterização hidrodinâmica dos dois solos.Knowledge of the soil hydraulic properties, such as the water retention theta(h) and hydraulic conductivity K(theta) curves, is indispensable for water and pollutant transport modeling of agricultural systems. Several experimental techniques have been proposed to determine these characteristic curves of the soil in the field. However, the complexity, the high costs and the time of execution of measurements are limiting factors for obtaining these characteristic curves in large areas. In this work, a simple methodology is shown, known as "Beerkan", which secks to overcome these difficulties. It uses experimental data of infiltration, bulk density and the particle-size distribution for estimating the theta(h) and K(theta) curves. This method was applied to two soils with different textural classification (three of an Oxisoil and three of an Alluvial Soil). For the hydrodynamic characterization, the shape and the normalization parameters of the theta(h) and of K(theta) curves were determined. The shape parameters depend upon the soil texture and they were obtained from the cumulative particle-size distribution curve; the normalization parameters depend on soil structure and they were obtained from the infiltration experiments using the simple ring infiltrometer. The Beerkan method proved to be robust and adapted to modeling the three-dimensional infiltration in field, as well as allowing the hydrodynamic characterization of the two soils.

The hydrodispersive characterization of two soils: an Yellow Ultisol and a Vertisol, both from the region of Sao Francisco Valley, was performed through displacement experiments in soil column in the laboratory. The experiment consisted of displacement of a pulse of 1 pore volume of a 0.1 M KBr solution in saturated soil column under steady-state flow conditions. The hydrodispersive parameters (D, R) ware obtained by fitting the analytical solution of the convection-dispersion equation (CDE) and the two-region transport model - MIM (D, R, β and ω ) for the points of the experimental breakthrough curve. The soil dispersivity was found to be higher in the Vertisol than in the Yellow Ultisol, because of the higher aggregation of this soil. The retardation factor (R) represented the tracer interactions with the soils: anionic exclusion in the Vertisol and bromide retention in the Yellow Ultisol, due to the presence of iron-oxydes (Goethite). The CDE model presented a better performance than the MIM model, for fitting the bromide breakthrough curves in both soil columns, suggesting the absence of immobile water in the Yellow Ultisol and the Vertisol.

Essays on the displacement of miscible liquid in soil columns in the laboratory were applied to hydrodisper- sive characterization of three soil samples with different textural classes: sandy loam, sandy clay loam and sand, from Alluvial soil on the banks of Cajueiro Dam in the Brazilian semi-arid. The essays comprise the displacement of 1/2 pulse pore volume from the CaCl2 solution at 0.01 M in soil columns under saturation conditions and steady water flow regime. The solute transport parameters were obtained by adjusting the analytical solution of the convec- tion-dispersion equation CDE (v, D), and the mobile- immobile solute transport model CDE-MIM (v, D, b and w), to the breakthrough curve points, by using the CXTFIT 2.0 computer program

Lectins from Canavalia brasiliensis (CnBr), Cratylia floribunda (CFL), Vatairea macrocarpa (VML) and Phaseolus vulgaris (PHA) aggregate Rhizobiumbacteria. The relationship between specific sedimentation rate, ν′ (based on bacterial dry biomass) of bacterial aggregates and lectin concentrations was hyperbolic and showed bacterial surface affinity by lectins. R. tropici (Rt), R. leguminosarum bv. phaseoli (Rlp) and R. etli (Re) surfaces showed predominantly receptors of galactosidic nature. The Rt surfaces showed very high affinities (k s = ±8.6 × 10−8 ag lectin protein ml−1) by Gal-specific lectins (PHA and VML), and very low affinities (ks=± 4.9 × 10−6) by Glc-specific lectins (CnBr and CFL). The Rlp surface had intermediate affinities by lectins. The Re surface showed high affinities by PHA (ks= ±1.26 × 10−8) and intermediate affinities by VML, CnBr and CFL. The relationship between sedimentation specific ν′′ (based on lectin weight) and bacterial density was a sigmoid and showed lectin affinity by Rt surfaces. The bacterial sedimentation showed positive cooperative binding of lectins. The V′′max induced by Glc-specific lectins was ±20 of that produced by Gal-specific lectins. The PHA affinity (ks= 1.19 mg dry biomass ml−1) was larger than VML (ks = 1.23). The Glc-specific lectin affinities were smaller than those of Gal-specific. The apparent binding site number of lectins (napp) was: 2.7-PHA; 2.2-VML; 3.2-CFL and 3.2-CnBr. The dissociation constant, ks, of lectin-binding kinetics decreased with sugar-hapten treatment (10 μM). The napp decreased in PHA and CFL, increasing in VML + sugar-hapten treatment. This study showed that there is a difference in Rhizobium surfaces for lectin binding.

A simplified model representing the small reservoir–ebb tide system by a set of different interacting water storage reservoirs has been proposed. The first one is the small reservoir, which represents the main water storage, accumulated during the rainy season. The second reservoir is the ebb tide zone. The link between the two reservoirs, the saturated zone, represents a buffer reservoir for water transfer. The water transfer in the system is described by a set of two balance equations, with two unknowns: water level in the reservoir and piezometric levels in the ebb tide area, both time-dependent. The solution for the set of equations depends on the equivalent saturated hydraulic conductivity of the medium and on atmospheric conditions. In order to evaluate the preferential flow throughout the network of fissures located in the deepest part of the reservoir two approaches have been considered, denominated the equivalent medium and the new model formulation. Four parameters were calibrated by inverse method using data of 70 days during a the monitoring period (23rd July–1st October 1998) and the model was validated for a 243 days period (17th April–16th December 1998) with different measured initial conditions and evaporation flux variation in time. Both the approaches were capable of reproducing the water levels in the reservoir and in the aquifer. In spite of differences in the estimated daily values, the two approaches predicted well-cumulative water flow and preferential flow. This study allowed a better understanding of the water transfer process in the reservoir–ebb tide system during the evaporation period.

Determinou-se a condutividade hidráulica e a sorvidade, a partir de dados de infiltração acumulada, utilizando-se um infiltrômetro a disco, em duas camadas de um Neossolo Flúvico (uma superficial, 15 - 25 cm de profundidade, argilosa, e outra 50 - 70 cm de profundidade, arenosa) da vazante do açude Flocos, localizado no município de Tuparetama, PE. Para a caracterização hidrodinâmica, os ensaios de infiltração foram realizados aplicando-se potenciais de fornecimento de água de 0, -3, -6 e -12 cm de coluna de água, utilizando um infiltrômetro a disco, com base de 80 mm de diâmetro. Três métodos foram empregados para se determinar a condutividade hidráulica (K) e a sorvidade (S) baseados no conhecimento prévio da curva de retenção da água no solo, obtida pelo ajuste das funcionais propostas por: i) van Genuchten (VG); ii) Russo (GR); e iii) Zhang & van Genuchten (ZV) aos valores experimentais de campo e de laboratório. A equação da infiltração acumulada em função do tempo descreveu com precisão os ensaios de infiltração realizados, apresentando coeficientes de determinação (R²) superiores a 0,995. O método GR parece ser o menos recomendado, pois superestima sistematicamente e prediz satisfatoriamente a condutividade hidráulica normalizada para ambas as camadas, enquanto o método VG a prediz razoavelmente, para ambas as camadas.Hydraulic conductivity (K) and sorptivity (S) of two layers with different textural classes of a Fluvents soil from Flocos dams, located in Tuparetama, PE, Brazil were determined using the cumulative infiltration data measured with an infiltrometer disk. During the infiltration experiments, water was applied to the soil by an infiltrometer disk at potentials equivalent to 0, -3, -6 e -12 cm of water columm. Three methods were used to evaluate K and S: i) van Genuchten (VG); ii) Russo (GR); e iii) Zhang & van Genuchten (ZV). These methods based on the previous knowledge of the soil-moisture characteristic curve, which were obtained by the adjustment of the functions proposed by each method. The equation of cumulative infiltration described with precision the infiltration experiments, and yielded determination coefficients (R²) greater than 0.995. The method GR is the less adequate, since it systematically overestimated values and did not predict well the normalized K for the two soil layers. On the other hand, the VG method yielded good predictions of normalized K for both soil layers.

Determinou-se a condutividade hidráulica e a sorvidade, a partir de dados de infiltração acumulada, utilizando-se um infiltrômetro a disco, em duas camadas de um Neossolo Flúvico (uma superficial, 15 - 25 cm de profundidade, argilosa, e outra 50 - 70 cm de profundidade, arenosa) da vazante do açude Flocos, localizado no município de Tuparetama, PE. Para a caracterização hidrodinâmica, os ensaios de infiltração foram realizados aplicando-se potenciais de fornecimento de água de 0, -3, -6 e -12 cm de coluna de água, utilizando um infiltrômetro a disco, com base de 80 mm de diâmetro. Três métodos foram empregados para se determinar a condutividade hidráulica (K) e a sorvidade (S) baseados no conhecimento prévio da curva de retenção da água no solo, obtida pelo ajuste das funcionais propostas por: i) van Genuchten (VG); ii) Russo (GR); e iii) Zhang & van Genuchten (ZV) aos valores experimentais de campo e de laboratório. A equação da infiltração acumulada em função do tempo descreveu com precisão os ensaios de infiltração realizados, apresentando coeficientes de determinação (R²) superiores a 0,995. O método GR parece ser o menos recomendado, pois superestima sistematicamente e prediz satisfatoriamente a condutividade hidráulica normalizada para ambas as camadas, enquanto o método VG a prediz razoavelmente, para ambas as camadas.

A determinação da condutividade hidráulica de um Podzólico Amarelo foi obtida a partir de experimento montado em uma parcela de 3,5 m x 3,5 m, localizada na Estação Experimental da Empresa Pernambucana de Pesquisa Agropecuária (IPA), de Itapirema, Goiana, PE. Foi utilizado o método de drenagem interna para calcular a condutividade hidráulica (K(q)) como função da umidade do solo, nos três horizontes característicos do solo. Os perfis de umidade e de potencial matricial, em função do tempo, obtidos no experimento de drenagem interna mostram claramente a existência de um joelho que marca a transição entre as fases de drenagem rápida e lenta. Várias funções do tipo potência, soma de duas e três exponenciais, foram usadas para modelar essa transição entre a fase rápida e a fase lenta de drenagem. O horizonte A, arenoso, com poros maiores, é um horizonte de elevada condutividade hidráulica, enquanto o horizonte BA, de estrutura maciça com poros pouco visíveis, é um horizonte de impedimento para a infiltração. A dinâmica hídrica do horizonte Bt é mais complexa em virtude de sua heterogeneidade. A caracterização dos horizontes A e BA pode trazer subsídios significativos para a elaboração de modelos de simulação numérica dos processos de transferência de água nos horizontes superficiais, que são os mais condicionantes para a exploração agrícola e a conservação dos solos. The determination of the hydraulic conductivity of a Yellow Podzolic soil was carried out during an experiment in a plot measuring 3.5 m x 3.5 m, at the Estação Experimental de Itapirema, Goiana, in the State of Pernambuco, Brazil. The internal drainage method was used to obtain the hydraulic conductivity (K(q)) as a function of soil water content, in the three main horizons of the soil. In relation to the methodological aspects, processing of data from internal drainage experiments, including the initial phase of fast drainage, the adjustment of the required parameters, it is necessary to use functions that reproduce the distinct transition between the fast and slow phases of drainage. From all five tested functions, those of power, sum of two exponentials and sum of three exponentials, especially this last one, adjusted well to this distinct transition. Three main horizons of the Yellow Podzolic soil were investigated for hydraulic conductivity. The sandy A horizon, with large pores, has a high conductivity while the BA horizon, with massive structure and few visible pores, has a low infiltration rate. The hydraulic dynamics of the Bt horizon is more complex due to its heterogeneity. The precise characterization of the A and BA horizons, which are the most important to agriculture and soil conservation, makes it possible to elaborate numeric simulation models of the water transference process in the surface horizons of this type of soil.

This study evaluated the effects of total and dissolved organic matter produced from two swine wastewater treatment systems, a biodigester and a manure lagoon, on the adsorption, desorption, and leaching of alachlor (2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide) in soil. It was used the batch equilibrium method to test adsorption and desorption, and the results are presented in Freundlich isotherms. It also used disturbed soil columns to evaluate the miscible displacement of alachlor in soil treated with total and dissolved organic matter. This assay was used to monitor the concentration of alachlor in the leached material, the amount of total organic carbon, and the pH. The addition of swine wastewater promoted greater adsorption and desorption of alachlor compared with the control. The dissolved organic matter promoted less soil adsorption of alachlor compared with the total organic matter and also interacted with the alachlor and/or competed with the exchangeable cation sites in the soil, resulting in greater leaching. The total organic matter contributed to the emergence of new sorption sites in the soil column, and the solids present in the composition may have blocked pesticide passage, resulting in lower loss of alachlor due to leaching.

O paclobutrazol (PBZ) é um regulador de crescimento utilizado em sistemas agrícolas com o propósito de controlar o crescimento vegetativo, estimulando a capacidade reprodutiva das plantas. Esse regulador de crescimento permanece ativo no solo por muito tempo, e sua meia-vida varia com o tipo de solo e as condições climáticas, podendo afetar severamente o desenvolvimento dos cultivos subseqüentes e, por lixiviação, contaminar os aqüíferos. Este trabalho teve como objetivo estudar os mecanismos envolvidos no transporte e na sorção do PBZ em colunas, utilizando amostras de um Argissolo Amarelo eutrófico e de um Vertissolo Háplico órtico, ambos da região do Vale do Rio São Francisco. Os ensaios de deslocamento miscível do traçador (solução de KBr) e do paclobutrazol foram realizados considerando duas vazões (0,4 e 1,6 cm³ min-1) para ambos os solos. As variáveis hidrodispersivas foram obtidas pelo ajuste do modelo convecção dispersão (CDE) às curvas de eluição experimentais do KBr, e as variáveis do modelo CDE-2 sítios de sorção, às curvas de eluição experimentais do PBZ por intermédio do programa CXTFIT 2.0. O paclobutrazol foi mais facilmente transportado no Vertissolo Háplico que no Argissolo Amarelo. A taxa de recuperação foi menor para a menor vazão para ambos os solos. A quantidade de PBZ não recuperada pode ser atribuída, sobretudo, à histerese no processo de sorção irreversível. O modelo CDE a dois sítios de sorção representa adequadamente os dados experimentais das curvas de eluição do paclobutrazol. Os resultados obtidos evidenciam que o paclobutrazol, utilizado em pomares com manga irrigada cujos solos são o Argissolo Amarelo e o Vertissolo Háplico, oferece risco real de contaminação das águas subterrâneas da região. Paclobutrazol (PBZ) is a post-emergence plant growth regulator used in agricultural systems with the objective of vegetative control growth, thereby increasing the reproductive capacity of the plant. This growth regulator remains active in the soil for several years being detrimental to subsequent tillage and contamination of groundwater through leaching. The objective of this work was to study the mechanisms involved in the transport and sorption of PBZ in an Ultisol and a Vertisol, both of the São Francisco Valley, Brazil. Column breakthrough experiments were performed with a water tracer (Bromide) and with PBZ at 0.4 e 1.6 cm³.min-1 in the two soils. Hydrodispersive parameters of both soils were obtained by fitting the tracer breakthrough curves (BTC) with the convection-dispersion (CDE) model, whereas the parameters of PBZ reactive transport were obtained with the CDE-2 sorption sites model, through the CXTFIT code. PBZ presents a lower retardation factor in the Vertisol than in the Ultisol. The water flow was found to strongly affect PBZ mass balance, mainly because of sorption/desorption hysteresis, suggesting partial irreversible sorption of the chemical. The two sites model fitted well the tracer and PBZ breakthrough curves. The results showed that PBZ transport is strongly influenced by its interactions with the soil matrix through rate-limited sorption. The determined transport parameters indicate that PBZ applied to the two tropical soils cultivated with Mango presents an important leaching potential and contamination risk of the groundwater of the São Francisco Valley.

O conhecimento das propriedades hidráulicas do solo, tais como as curvas de retenção da água no solo teta(h) e da condutividade hidráulica K(teta), é indispensável para a modelagem do transporte de água e de poluentes em sistemas agrícolas. Várias técnicas experimentais têm sido propostas para determinar essas características do solo diretamente no campo, porém a complexidade, os custos elevados e o tempo de execução dessas medidas, são fatores que limitam bastante a obtenção dessas informações em grande escala. Apresenta-se, no presente trabalho, uma metodologia conhecida como "Beerkan", com a qual se busca minimizar esses fatores utilizando-se dados experimentais de infiltração, da distribuição granulométrica e da massa específica do solo, para então se estimar os parâmetros das curvas de teta(h) e K(teta). O método foi aplicado em dois solos com diferentes classes texturais (três de um Latossolo Amarelo e três de um Neossolo Flúvico). Determinaram-se, com vistas à caracterização hidrodinâmica, os parâmetros de forma das curvas de teta(h) de van Genuchten e de K(teta) de Brooks e Corey, dependentes majoritariamente da textura do solo e obtidos a partir da curva de distribuição dos tamanhos das partículas, além dos parâmetros de normalização dependentes, essencialmente, da estrutura do solo e obtidos a partir dos ensaios de infiltração utilizando-se o infiltrômetro de anel simples. O método Beerkan provou ser robusto e adaptado à caracterização hidrodinâmica dos dois solos. Knowledge of the soil hydraulic properties, such as the water retention theta(h) and hydraulic conductivity K(theta) curves, is indispensable for water and pollutant transport modeling of agricultural systems. Several experimental techniques have been proposed to determine these characteristic curves of the soil in the field. However, the complexity, the high costs and the time of execution of measurements are limiting factors for obtaining these characteristic curves in large areas. In this work, a simple methodology is shown, known as "Beerkan", which secks to overcome these difficulties. It uses experimental data of infiltration, bulk density and the particle-size distribution for estimating the theta(h) and K(theta) curves. This method was applied to two soils with different textural classification (three of an Oxisoil and three of an Alluvial Soil). For the hydrodynamic characterization, the shape and the normalization parameters of the theta(h) and of K(theta) curves were determined. The shape parameters depend upon the soil texture and they were obtained from the cumulative particle-size distribution curve; the normalization parameters depend on soil structure and they were obtained from the infiltration experiments using the simple ring infiltrometer. The Beerkan method proved to be robust and adapted to modeling the three-dimensional infiltration in field, as well as allowing the hydrodynamic characterization of the two soils.

Baseado nos conceitos da geometria fractal e nas leis de Laplace e de Poiseuille, foi criado um modelo geral para estimar a condutividade hidráulica de solos não saturados, utilizando a curva de retenção da água no solo, conforme representada por um modelo em potência. Considerando o fato de que este novo modelo da condutividade hidráulica introduz um parâmetro de interpolação ainda desconhecido, e que, por sua vez, depende das propriedades dos solos, a validação do modelo foi realizada, utilizando dois valores-limite fisicamente representativos. Para a aplicação do modelo, os parâmetros de forma da curva de retenção da água no solo foram escolhidos de maneira a se obter o modelo de van Genuchten. Com a finalidade de obter fórmulas algébricas da condutividade hidráulica, foram impostas relações entre seus parâmetros de forma. A comparação dos resultados obtidos com o modelo da condutividade e a curva experimental da condutividade dos dois solos, Latossolo Vermelho-Amarelo e Argissolo Amarelo, permitiu concluir que o modelo proposto é simples em sua utilização e é capaz de predizer satisfatoriamente a condutividade hidráulica dos solos não saturados. From a conceptual model based on fractal geometry and Laplace's and Poiseuille's laws, a versatile and general fractal model for the hydraulic conductivity to be used in the soils was developed. The soil-moisture retention curve is derived from a power model. Due to the fact that the proposed model of hydraulic conductivity introduces a still unknown interpolation parameter, which in turn is a function of soil properties, its limiting values were considered for the analysis. To apply the model in the soil, the form parameters of the soil-moisture retention curve were chosen so as to reproduce van Genuchten's equation. In order to obtain a closed-form equation for the hydraulic conductivity, relationships between the form parameters were imposed. The comparison between the predicted and experimental hydraulic conductivity from two soils, Oxisol and Yellow Utilsol, demonstrated that the proposed model is flexible and that it can be used to predict the unsaturated hydraulic conductivity of soils with good accuracy.

International audience; In Northeast Brazil, more than 70,000 small dams retain superficial runoff and underground water flow, creating small reservoirs. Recession agriculture consists of cropping the margins of the reservoirs, on slight slopes, while the water level progressively decreases, and it is a widespread cropping system in this area. The water balance for this particular system was quantified on two contiguous plots, one with “Marreca” grass (Paspalum conjugatum Berg.), a forage crop, and the other one on bare soil, in the recession zone of the basin of Flocos dam, municipality of Tuparetama, PE (7°36′S and 37°18′W). The soil, classified as Fluvent, consists of a superficial clay textured layer overlying a sandy layer. Next to the dam, a meteorological station was installed, equipped with automatic sensors for recording rainfall, air temperature and wind speed, and pan evaporation. In the reservoir, the water level was recorded. The plots were instrumented with one neutron probe access tube, one piezometer and tensiometers at different soil depths. Water retention and hydraulic conductivity characteristics were determined through field and laboratory measurements. The water balance was determined for the cropped and the bare soil plots, during 67 days. Average values for the actual evaporation and evapotranspiration rate, were respectively 5.0 and 8.0 mm day−1, with an average reference evaporation rate of 8.7 mm day−1. The contribution of the aquifer recharge to evaporative demand was estimated and found to be very important. Field observation and the estimated aquifer recharge from the reservoir suggest the presence of preferential flow. The study of water dynamics in this system is fundamental for establishing a basis for the sustainable development of agriculture in this area.

A distribuição probabilística do fator de escala da camada superficial, considerando-se a teoria dos meios fractais auto-similares, foi determinada para dois solos do Estado da Paraíba. O estudo foi realizado em duas áreas experimentais, com distintas condições de clima e solo, de aproximadamente 4 ha. A primeira na Fazenda Várzea Grande, no município de São João do Cariri, PB (7º23'S e 36º31'O) com o solo classificado como Neossolo Flúvico enquanto a segunda, se localiza no Centro de Ciências Agrárias, da UFPB, no município de Areia, PB (6º58'S, 35º41'O), com o solo classificado como Latossolo Amarelo. Para estimar a condutividade hidráulica à saturação do solo, realizaram-se ensaios de infiltração com infiltrômetro de anel (15 cm de diâmetro) na superfície do solo, em 80 pontos distribuídos regularmente em uma malha de 25 x 25 m. Para ambos os solos, o logaritmo dos fatores de escala que intervém nos fractais auto-similares segue uma distribuição de Gauss ou distribuição normal. A função de distribuição probabilística permitiu estimar a dimensão fractal do meio poroso, que representa os solos estudados. The probabilistic distribution of the scale factor of superficial layer was determined, considering the similar fractal theory for two soils in the Paraíba State. The study was performed at two experimental sites, with different climate and soil conditions of approximately 4 ha. The first was located in the Várzea Grande farm, in the municipality of São João do Cariri, PB (7º23'S e 36º31'O). The soil was classified as Fluvent. The second was located in the Centro de Ciências Agrárias, of the UFPB, in the municipality of Areia, PB (6º58'S, 35º41'W). The soil was classified as Oxisol. To estimate the soil saturated hydraulic conductivity, infiltration experiments were performed using a ring infiltrometer (15 cm diameter) on the soil surface, at 80 points on a regular mesh of 25 x 25 m. For both soils, the logarithms of the scale factors followed a Gaussian distribution or normal distribution. The probabilistic distribution function allowed the estimation of the fractal dimension of the porous media that represent the studied soils.

Este estudo teve como objetivo avaliar os efeitos da variabilidade da precipitacao no balanco hidrico diario e suas implicacoes em relacao aos cenarios climaticos futuros na cultura do feijao caupi (Vigna Unguiculata). Realizou-se o balanco hidrico diario, cujos dados de entrada foram a chuva e a evapotranspiracao diarias no periodo de abril a junho do ano de 2004, na localidade de Palmares – PE. O feijao caupi, foi escolhido como cultura de referencia, devido a sua importância alimentar e a sua adaptacao as condicoes edafico-climaticas da regiao. Os resultados obtidos por meio do balanco hidrico e a avaliacao na distribuicao das temperaturas e chuvas diarias apontaram como fatores limitantes para o desempenho satisfatorio do feijao cultivado em sequeiro, a irregularidade na distribuicao pluviometrica ao longo dos estagios de desenvolvimento e o aumento de temperatura de 2 °C, esses fatores influenciam diretamente a producao final. Portanto, se nos proximos 50 anos houver um aumento de temperatura de 2 °C, em decorrencia do aquecimento global, provavelmente esta cultura necessitara de novas adaptacoes geneticas, bem como novas areas de plantios e adequacoes no periodo de semeadura. Palavras-chave: variabilidade pluviometrica, aquecimento global, balanco hidrico e feijao caupi. Impact of Global Warming on Daily Water Balance and its Consequences for Agriculture ABSTRACT This study it had as objective to evaluate the effect of the variability in precipitation in the daily hydric balance and its implications in relation to the future climatic scenes in the culture of the beans caupi. The daily hydric balance data were used daily rainfall and the evapotranspiration in the period of April the June of the year of 2004, in the locality of Palmares - PE. The beans caupi, was chosen had its alimentary importance and its adaptation the edaficoclimatic conditions of the region. The results gotten by means of the hydric balance and the evaluation in the distribution of the temperatures and daily rains, had pointed as restriction factors with respect to the satisfactory performance of the beans cultivated in dry land, the irregularity in the precipitation distribution to long of the periods of training of development and the increase of temperature of 2 °C. Those factors influence direct in the production end. Therefore, if in next the 50 years it will have the increase of temperature of 2 °C, in result of the global heating, probably this culture will need new genetic adaptations, as well as new areas of plantations and adequacies in that it says respect to the period of sowing. Keywords: variability precipitation, global heating, water balance, beans caupi.