Proceedings
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| Filter results10 paper(s) found. |
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1. Soybean Yield Response to Apparent Soil Electrical Conductivity–based Management ZonesManagement zone delineation is a key strategy in precision agriculture, as it enables a better understanding and managing spatial variability in soil attributes and crop yield. Apparent soil electrical conductivity (ECa) has been widely used as an indirect indicator of soil physical and chemical properties and as a basis for defining homogeneous management zones. The objective of this study was to evaluate soybean yield behavior within management zones delineated using soil ECa.The study was conducted... E.L. Bottega, Z.B. Oliveira, D. Queiroz, A. Luiz De Freitas Coelho, G.B. Bernhard |
2. Validation of UAV-Based NDVI Using Proximal Sensing in Mountain Coffee PlantationsUnmanned aerial vehicles (UAVs) with multispectral sensors have expanded remote sensing applications in precision agriculture, however validation against ground-truth measurements remains critical, especially for perennial crops in complex terrain such as coffee plantations in mountainous regions. Proximal sensing can be employed as a reference for evaluating the quality of data obtained by remote platforms. This study aimed to evaluate the reliability of Normalized Difference Vegetation Index... B. Costalonga Vargas, I.A. Barbosa, D. Queiroz, A.L. Coelho, D.M. Valente, M.C. Moreira |
3. Delimitation of Management Zones in Agroforestry Coffee SystemsThe search for more sustainable agricultural production systems is a common goal for both agroforestry systems and precision agriculture. Integrating precision agriculture technologies into coffee cultivation within agroforestry systems has the potential to make these systems more efficient, productive, and sustainable. Thus, this study aims to test the effect of different variables on the delimitation of management zones (MZs) in agroforestry systems. The study was conducted on two coffee-producing... W. Silva Dos Santos, D. Queiroz, F.C. Pinto, A.L. Coelho, B.N. Vasconcelos |
4. Prediction of Soil Potassium Concentration Using Electrical Impedance SpectroscopyThe increasing global dependence on potassium fertilizers and instabilities in international trade, intensified by recent geopolitical conflicts, have raised concerns regarding potassium (K) availability and costs in 2026. Since variable-rate fertilizer application enables the optimization of agricultural inputs, the delineation of management zones based on the spatial variability of soil potassium concentration becomes essential. This study aimed to evaluate the use of electrical impedance spectroscopy... I. Salvador, A.L. Coelho, S.V. Valarares, D. Queiroz |
5. Performance of Autonomous Navigation in an Agricultural Tractor Using Pure Pursuit Control and Dubins Path PlanningAutopilot systems in agricultural machinery are primarily designed to ensure accurate tracking of predefined routes. However, their performance is strongly influenced by the internal parameters of the control algorithms employed, which may vary according to operational conditions. In this context, computational simulations constitute a valuable tool for investigating these interactions and identifying optimal operating configurations. This study evaluates an autopilot system based on the Pure... J.D. Baltazar, A.L. Coelho, L. De Arruda Viana, A.D. Brandão, D.S. Valente, M.R. Furtado Jr |
6. Comparison of Orbital and UAV Remote Sensing for Coffee Crop Monitoring in Mountainous TerrainMonitoring coffee crops is an important step for the success of production systems. Recently, manual field inspections have been replaced by automated techniques aimed at improving spatial coverage and reducing costs. One such technique is remote sensing, which can be performed using both orbital platforms and Unmanned Aerial Vehicles (UAVs). However, coffee cultivation presents significant imaging challenges due to plant spacing, where wide row spacing results in greater spectral variability... I. Araújo Barbosa, M.H. Pereira, D. Queiroz, A.L. Coelho, D. Sárvio Valente, M.C. Moreira |
7. Temporal Variability of Vegetation Indices and Spatial Autocorrelation Applied to Specific Management in Mountain Coffee CropsThe characterization of spatial and temporal variability in agricultural crops is an important stage for the application of precision agriculture, enabling the definition of management zones and the prescription of inputs for variable rate application. In this context, the use of unmanned aerial vehicles (UAVs) equipped with multispectral sensors has enabled the acquisition of spectral data with spatial and temporal resolutions compatible with the objectives of the intended activity. Associated... I. Araújo Barbosa, D. Queiroz, A.L. Coelho, D. Sárvio Valente, M.C. Moreira, B. Costalonga Vargas |
8. Estimation of Leaf Chlorophyll Index in Corn Using Smartphone Images and Machine LearningAccurate estimation of the Leaf Chlorophyll Index (LCI) in corn is fundamental for nitrogen management in precision agriculture, as nitrogen availability directly affects chlorophyll production and photosynthetic capacity. Conventional field assessment techniques are time-consuming and labor-intensive, while smartphone use provides a practical and low-cost alternative for obtaining high-resolution data in near-real-time. The objective of this study was to develop and validate a non-destructive... C.C. Santana, S.M. Mintesinot, D. Queiroz, F.S. Santos, A.L. Coelho |
9. Evaluation of Variable-Rate Application of Growth Regulator in CottonThe application of plant growth regulators in cotton is widely used to control excessive vegetative growth and improve plant architecture. However, the spatial variability present in agricultural fields may reduce the efficiency of conventional fixed-rate application, making variable-rate application (VRA) a promising alternative. The objective of this study was to evaluate the effect of fixed-rate and variable-rate application of the growth regulator mepiquat chloride on plant height, leaf area... B. Costalonga Vargas, M.R. Furtado Junior, G.O. Paula, A.L. Coelho, M.C. Moreira, F.R. Carvalho |
10. Flow Rate and Discharge Coefficient Behavior of Spray Nozzles in a PWM SystemPulse width modulation (PWM) technology has been widely used in variable-rate pesticide applications, allowing flow control by varying the duty cycle while maintaining constant pressure. However, the intermittent operation of the flow may alter the hydraulic behavior of spray nozzles, influencing both the effective flow rate and the discharge coefficient (Cd). In this context, the objective of this study was to evaluate the behavior of flow rate and discharge coefficient of different spray nozzles... B. Costalonga Vargas, M.R. Furtado Júnior, A.L. Coelho, S. Basilio |