Engenharia Agrícola - Artigos
URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11739
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Item Variabilidade espacial de atributos do solo em sistema de semeadura direta com rotação de culturas no cerrado brasileiro(Revista Ciência Agronômica, 2013-01) Bottega, Eduardo Leonel; Queiroz, Daniel Marçal de; Pinto, Francisco de Assis de Carvalho; Souza, Cristiano Márcio Alves deO presente estudo objetivou analisar a variabilidade espacial dos atributos químicos e da textura de um Latossolo Vermelho distroférrico. A propriedade onde o estudo foi realizado localiza-se no município de Sidrolândia (MS) e produz soja, milho e algodão, adotando rotação de culturas e o sistema de plantio direto. Em uma área experimental de aproximadamente 90 hectares foi amostrado solo em 181 pontos georeferenciados. As amostras foram compostas por quatro amostras simples, representativas da profundidade de 0,00-0,20 m. Foram mensurados os atributos químicos e a textura do solo. Realizou-se, inicialmente, análise de discrepantes e, posteriormente, análise descritiva e geoestatística para caracterizar as amostras e identificar a dependência espacial dos atributos estudados. Não foi detectada dependência espacial para os atributos acidez ativa em água, alumínio, acidez potencial, saturação por bases e matéria orgânica. As melhores estimativas de valores para locais não amostrados foram observadas para os atributos físicos do solo, os quais apresentaram os melhores parâmetros de ajuste dos variogramas e da validação cruzada. As técnicas de geoestatística utilizadas possibilitaram o ajuste dos modelos teóricos que melhor representaram a semivariância experimental, possibilitando assim a construção de mapas temáticos da distribuição espacial dos valores dos atributos do solo estudado.Item Espacialização de perdas e da qualidade do feijão em colheita semimecanizada(Acta Scientiarum. Agronomy, 2010) Souza, Cristiano Márcio Alves de; Bottega, Eduardo Leonel; Vilela, Fábio Velloso; Rafull, Leidy Zulys Leyva; Queiroz, Daniel Marçal deO objetivo deste trabalho foi analisar o efeito da distribuição espacial do teor de água dos grãos e da produtividade do feijoeiro sobre as perdas e a qualidade do produto durante o processo de arranquio, recolhimento, trilha e separação em uma recolhedora-trilhadora. O trabalho foi realizado em uma área de 35 ha sob pivô central. Foi determinado o teor de água dos grãos no arranquio e no recolhimento, a produtividade total e líquida da lavoura, a velocidade de trabalho da máquina, a quantidade de grãos perdidos no arranquio, no recolhimento e na trilha e separação e a porcentagem de matéria estranha e própria do feijoeiro presente no produto. As perdas de grãos e a qualidade do produto colhido apresentaram elevada variação de seus valores na área, indicando a necessidade de regulagem específica da recolhedora-trilhadora em cada caso durante a colheita, em função do teor de água e da produtividade.Item The use of different sampling grids in determining the variability of soil physical attributes of Oxisol(Comunicata Scientiae, 2014-04) Bottega, Eduardo Leonel; Queiroz, Daniel Marçal de; Pinto, Francisco de Assis de Carvalho; Santos, Nerilson TerraThis study aimed to analyze the influence of different sampling grids in determining the spatial variability of physical attributes of Oxisol. It was used to study an area of approximately 90 hectares, where soil was sampled at depth from 0 to 0.20 meters, using a grid of 2 points per hectare (G1). Each soil sample was composed of four subsamples and obtained using a soil sampler Dutch type. The samples were sent to the laboratory to granulometric analysis. From the initial grid, the area was divided into sampling cells of 2.9 (G2) and 4.7 hectares (G3), and assigned a coordinate value representative of the center of each cell. Classical statistical and geostatistical methods were used to characterize the data and to model the spatial dependence. Spatial dependence was detected for all physical variables of the soil, regardless of the sampling grid used. The utilization of sampling grid of 1 point for each 2.9 hectares, and the sampling cell characterized by 12 subsamples, showed itself capable of detecting the spatial variability of the physical attributes of the soil, guaranteeing reliability in the estimates, even reducing the quantity of points when compared to the densest grid.Item Correlação entre condutividade elétrica aparente e atributos químicos e físicos de um Latossolo(Comunicata Scientiae, 2015-04) Bottega, Eduardo Leonel; Queiroz, Daniel Marçal de; Santos, Nerilson Terra; Pinto, Francisco de Assis de Carvalho; Souza, Cristiano Márcio Alves deA agricultura de precisão vem sendo utilizada como importante técnica de manejo localizado da fertilidade do solo. Para tanto, é indispensável à caracterização da variabilidade espacial dos atributos químicos e físicos do solo através de amostragem capaz de representar tais variações. O presente estudo teve por objetivo analisar a correlação entre a condutividade elétrica aparente com os atributos químicos e físicos de um Latossolo Vermelho distroférrico. O trabalho foi realizado em uma propriedade localizada no cerrado brasileiro. Em uma área de 90 hectares foram coletados 181 amostras de solo georeferenciadas, na profundidade de 0,00 – 0,20 metros. Nos mesmos locais de retirada de amostras foram efetuadas leituras de condutividade elétrica aparente do solo. As amostras foram encaminhadas ao laboratório para realização das análises física e química. Selecionou-se, aleatoriamente, 30 pontos amostrais e calculou-se o coeficiente de correlação de Pearson entre as variáveis físicas, químicas e a condutividade elétrica aparente do solo. Não foi observado correlação significativa entre a condutividade elétrica aparente com os atributos físicos do solo. Observou-se correlação positiva e significativa da condutividade elétrica aparente do solo na profundidade de 0,20 m com os atributos químicos fósforo, fósforo remanescente e zinco.Item An open-source spatial analysis system for embedded systems(Computers and Electronics in Agriculture, 2018-11) Coelho, Andre Luiz de Freitas; Queiroz, Daniel Marçal de; Valente, Domingos Sárvio Magalhães; Pinto, Francisco de Assis de CarvalhoSoil and plant monitoring systems are important tools for applying precision agriculture techniques. To acquire soil-plant system data, the user establishes a sampling strategy, goes to the field, collects data and finally goes to the office for data analysis. Sometimes, when the analysis is performed, the user realizes that the sampling strategy was not adequate and needs to return to the field in order to collect more data. To avoid problems with the sampling strategy, the solution is to have a system that performs the data analysis immediately after its collection, while the user is still in the field. To do that, we can use single board computers; these types of platforms have ports to communicate to sensors and good processing capabilities. Therefore, the objective of this work was to develop an embedded system to perform spatial variability data analysis in the field, right after data acquisition. The software was developed using Python 3.6; the PyQt Integrated Development Environment (Riverbank Computer Limited, Dorchester, United Kingdom) was used to design a graphical user interface. The BeagleBone Black board, running Debian version 8.6, was used to implement the software. The analysis was divided into three steps: in the first one, an outlier and inlier analysis was performed to remove unwanted data; in the second one, the semivariogram was generated, and the variable and standard deviation map was produced by performing ordinary kriging; and in the last one, a cluster analysis was performed to create management classes using a fuzzy k-means algorithm. The graphical user interface showed the variable map and the variable classes map. To test the developed software, soybean yield data that was collected in a 31.6-ha field were used. The developed software was shown to be efficient at performing the spatial variability of soybean yields. The comparison of the generated maps shows the importance of filtering the data before performing the analysis. The developed software is available at the GitHub website.Item Spatial variability in nutritional status of arabic coffee based on dris index(Revista Ceres, 2011-02) Silva, Samuel de Assis; Lima, Julião Soares de Souza; Queiroz, Daniel Marçal deThe combined use of precision agriculture and the Diagnosis and Recommendation Integrated System (DRIS) allows the spatial monitoring of coffee nutrient balance to provide more balanced and cost-effective fertilizer recommendations. The objective of this work was to evaluate the spatial variability in the nutritional status of two coffee varieties using the Mean Nutritional Balance Index (NBIm) and its relationship with their respective yields. The experiment was conducted in eastern Minas Gerais in two areas, one planted with variety Catucaí and another with variety Catuaí. The NBIm of the two varieties and their yields were analyzed through geostatistics and, based on the models and parameters of the variograms, were interpolated to obtain their spatial distribution in the studied areas. Variety Catucai, with grater spatial variability, was more nutritional unbalanced than variety Catuai, and consequently produced lower yields. Excess of Fe and Mn makes these elements limiting yield factors.Item Moisture content effect in the relationship between apparent electrical conductivity and soil attributes(Acta Scientiarum. Agronomy, 2012-10-31) Costa, Marcelo Marques; Queiroz, Daniel Marçal de; Pinto, Francisco de Assis de Carvalho; Reis, Elton Fialho dos; Santos, Nerilson TerraTo map the spatial variability of a field to define the variable rate application, an intensive sampling of the soil-plant system is necessary. The apparent soil electrical conductivity (ECa) has been used for soil mapping because it correlates well with soil attributes, allows for dense sampling and can be obtained at low cost. However, ECa is influenced by soil moisture content, and the variability of this attribute can reduce the reliability of the ECa maps to explain the physical and chemical soil attributes. The objective of this study was to identify conditions that maximize the correlations between the ECa and the soil attributes. The results show that the mean soil moisture content of soil sampled on different dates was correlated with the mean of the ECa. The ideal time for measuring ECa occurred when the mean moisture content of the soil was higher. In this condition, the coefficient of variation for the soil moisture content was lower, there was no correlation between ECa and soil moisture content, and ECa was more correlated with other soil attributes evaluated in this work.Item Cacao crop management zones determination based on soil properties and crop yield(Revista Brasileira de Ciência do Solo, 2016-04-12) Carvalho, Perla Silva Matos de; Franco, Laís Barreto; Silva, Samuel de Assis; Sodré, George Andrade; Queiroz, Daniel Marçal de; Lima, Julião Soares de SouzaThe use of management zones has ensured yield success for numerous agricultural crops. In spite of this potential, studies applying precision agricultural techniques to cacao plantations are scarce or almost nonexistent. The aim of the present study was to delineate management zones for cacao crop, create maps combining soil physical properties and cacao tree yield, and identify what combinations best fit within the soil chemical properties. The study was conducted in 2014 on a cacao plantation in a Nitossolo Háplico Eutrófico (Rhodic Paleudult) in Bahia, Brazil. Soil samples were collected in a regular sampling grid with 120 sampling points in the 0.00-0.20 m soil layer, and pH(H2O), P, K+, Ca2+, Mg2+, Na+, H+Al, Fe, Zn, Cu, Mn, SB, V, TOC, effective CEC, CEC at pH 7.0, coarse sand, fine sand, clay, and silt were determined. Yield was measured in all the 120 points every month and stratified into annual, harvest, and early-harvest cacao yields. Data were subjected to geostatistical analysis, followed by ordinary kriging interpolation. The management zones were defined through a Fuzzy K-Means algorithm for combinations between soil physical properties and cacao tree yield. Concordance analysis was carried out between the delineated zones and soil chemical properties using Kappa coefficients. The zones that best classified the soil chemical properties were defined from the early-harvest cacao yield map associated with the clay or sand fractions. Silt content proved to be an inadequate variable for defining management zones for cacao production. The delineated management zones described the spatial variability of the soil chemical properties, and are therefore important for site-specific management in the cacao crop.