Scielo RSS <![CDATA[Engenharia Agrícola]]> vol. 37 num. 5 lang. en <![CDATA[SciELO Logo]]> <![CDATA[FORM OF LAYING HENS EGGS IN THE FUNCTION OF DIFFERENT LAMPS USED IN PRODUCTION]]> ABSTRACT: Lighting, either in its intensity or in its luminous spectrum, affects the eggs quality. This study evaluated the effect of four lamps (sodium vapor lamp, mercury vapor lamp, fluorescent lamp and incandescent lamp) that have different luminous spectra in the form of commercial poultry eggs. For this, 60 laying hens of the same age were separated for 63 days in four aviaries with reduced and distorted scale. In each treatment, different lamps were installed which provided similar luminous intensities. At the end of the period, these eggs were taken as samples for the fluorescent, incandescent, mercury vapor and sodium vapor lamps. In this way, images were made of these eggs, using a camera installed on a fixed tripod on a flat table with black background. In a room with controlled lighting, ensuring the same distance and angle for all eggs. The Matlab® program was used to perform the image analysis, recording measurements of area, perimeter and minimum and maximum distances of the mass center of each egg. The measurements were grouped by treatment and the Tukey's test of averages was applied. The results showed that the eggs removed from the sodium vapor treatment presented a more elongated shape. It is concluded that the light spectrum of the lamps affects the shape of the eggs and this should be considered in the planning of lighting programs in aviaries. <![CDATA[TECHNICAL FEASIBILITY OF THE ACCLIMATIZATION SYSTEM IN AVIARY OF POSTURE: A CASE STUDY]]> ABSTRACT: The objective of this study was to compare the performance of laying hens between automated aviaries, one with and another without acclimatized system. On a daily basis it was registered in each aviary the mortality, the egg production, and the feed consumption. The variables of the dry bulb temperature, relative humidity and black globe temperature were registered every 30 minutes using the thermos hygrometer. Every 28 days ninety eggs from each aviary were collected randomly and the variables egg weight, shell weight, shell thickness and Haugh Unit were registered. The consumption and quality of the electrical energy supply were monitored every 30 minutes using registers of electrical magnitude. The results showed that the acclimatization system consumes more electrical energy; however it provides thermal environment more suitable for bird raising, resulting in better production and quality of the eggs. The quality of the electrical energy supply was not maintained, since several interruptions occurred which resulted in higher mortality in the acclimatized aviary. It was concluded that the acclimatization system is technically feasible, since the electrical energy supply is guaranteed. <![CDATA[MEASUREMENT AND ANALYSIS OF A FIELD AREA BASED ON AN ADAPTIVE KALMAN FILTER]]> ABSTRACT: This paper proposed the use of an adaptive Kalman filter (AFK) to improve Global Positioning System (GPS) positioning accuracy to measure a tractor operational area. First, we used MATLAB to identify the operation trajectory. Then, we used different colors to show the area of operation. Finally, we used an image-processing method to calculate the effective operational area, actual operational area, and repeat and omission rates. We used these rates to evaluate the tractor efficiency. The experiment indicated that the Kalman filter improved the accuracy of GPS single-point positioning. To test the GPS area-measurement precision, field area measurements were taken. We used GPS to measure standard figures and some irregular figures. The results indicate that the area measurement relative error was 2.09%. The measurement accuracy increased with the increasing measurement area. The field test results indicated that the most efficient farming method was alternative tillage and the second most efficient was spindle tillage. The omission rate under back tillage was highest and its operational efficiency was lowest. <![CDATA[CLOACAL AND SURFACE TEMPERATURES OF BROILERS SUBJECT TO THERMAL STRESS]]> ABSTRACT: The cloacal and surface temperatures are important physiological parameters to quantify the thermal comfort of animals, its variations may occur as a function of thermal variables. In this context, the goal of the present study was to evaluate the cloacal (tclo) and surface (tsur) temperatures of Cobb 500® broilers, in the second week of life, subjected to different air dry-bulb temperature (24, 27, 30 and 33 °C) and stress durations (1, 2, 3 and 4 days). The experiment was carried out in four climate-controlled wind tunnels. Air relative humidity and air velocity were set at 60% and 0.2 m s-1, respectively. The tclo and tsur were measured daily through digital thermometer and thermographic camera, respectively. Analysis of variance and Scott Knott mean test at 5% probability were applied to the data. The results indicate that the stress by low air temperature (24 and 27 °C) resulted decreased of tclo and tsur (p&lt;0.05, Scott-Knott test). When subjected to high air temperature stress (33 °C), there was no significant difference (p&gt;0.05, Scott-Knott test) compared to the control treatment (30 °C). Acclimation of broilers to thermal stress occurred from the second day of stress. <![CDATA[EVATUATION SYSTEM OF EXHAUST FANS USED ON VENTILATION SYSTEM IN COMMERCIAL BROILER HOUSE]]> ABSTRACT: This study aim to develop a system, called FANS-N, for evaluation the exhaust fans in the ventilation system of broiler facilities. The system is divided into: 1) Mechanical Structure - consisting of two stepper motors for positioning a anemometer sensor in the vertical and horizontal coordinates; 2) Electronic Interface - control of the anemometer positioning and record data of wind speed; 3) Control Programming Module – accountable for the cursor movement, measurement and record the wind speed data with the anemometer at predetermined points; and 4) Analysis Programming Module - responsible for the interpretation of wind speed values at each point. The software uses artificial neural networks (Multi-Layer Perceptron) for images analyses of data base. The output of neural network give to the user the following recommendations: "possible changing", "maintenance", "standard limit", and "within standard". The system was able to evaluate the exhaust fans, identify the failures and proposing solutions to farmers of a preventive diagnosis. <![CDATA[PHYSICAL-MECHANICAL CHARACTERIZATION OF <em>Eucalyptus urophylla</em> WOOD]]> ABSTRACT: Eucalyptus urophylla consists in a wood-producing species, which offers a natural multiple raw material of good quality for applications in rural and civil constructions. However, Eucalyptus urophylla still has a small utilization as building parts and elements, resulting from the possible ignorance and low diffusion of its structural possibilities. Thereby, the present research aims to measure the main thirteen mechanical properties of Eucalyptus urophylla wood for two different moisture contents, 12% and 30% (green wood). Furthermore, in these two conditions of moisture content evaluation, volumetric mass densities were also evaluated. At the end of this evaluation, which included 2688 determinations, all the obtained results were statistically treated with t-test at a 5% of significance level in order to evaluate the influence of moisture content in the evaluated properties. Twelve mechanical properties were significantly affected by moisture content, and the behavior pattern consisted in increasing the values of the properties with the reduction of the moisture content. <![CDATA[ENERGY BALANCE OF IRRIGATED AND RAINFED SORGHUM PRODUCTION]]> ABSTRACT: The objective of this study was to evaluate the yield and energy balance of four sorghum genotypes in irrigated and rainfed crops. The experiment was conducted in an irrigation and drainage unit at the Federal University of Grande Dourados (UFGD), in Dourados, Mato Grosso do Sul state (Brazil). The experimental design was a randomized complete block design with split plots (with and without irrigation), testing four genotypes (BRS 506, CV 007, CV 147, and EJ 7281) with four replicates (32 plots). Irrigation provided yield increase in all four genotypes. The respective yield increases were 85.89%, 71.82%, 64.28%, and 63.36% for genotypes EJ 7281, BRS 506, CV 147, and CV 007. The energy efficiency (produced/ used ratio) was on average 3.5 under irrigation, and 2.8 for rainfed crops. These results indicate the lack of competition between sorghum and sugarcane, being the first an alternative for off-season. Irrigation increased productivity, leading to an increase in yield and, consequently, in the amount of extracted energy. Yield gains in response to irrigation were more pronounced for genotype EJ 7281. There was a positive impact of irrigation on the energy balance of the four genotypes, increasing energy efficiency. <![CDATA[INTEGRATED ENVIRONMENTAL FOOTPRINT INDEX (IEFI): MODEL DEVELOPMENT AND VALIDATION]]> ABSTRACT: Freshwater is a valuable resource worldwide given the growing demand of the global population. This study aimed to develop and validate an integrated assessment model by means of environmental footprint indices (water, ecological, and carbon), which measure the environmental sustainability of heterogeneous communities, people, and countries. An environmental footprint was firstly defined as a set of indicators to track human pressure on planet Earth under different angles, being a multidimensional index of environmental sustainability. A Delphi survey was used to bring together opinions from a diverse set of experts. The participants of this study consisted of 120 experts from several fields of knowledge belonging to the best-known research and education institutions in Brazil. Through this technique, an integrated environmental footprint index (IEFI) could be developed, being then validated with information from eight different communities located in the Paraíba State (Brazil). Afterwards, this index was applied to several representative countries from all continents. Our results indicated the sensitiveness of IEFI model to variations in natural ecosystems, in addition to its ability to identify the environmental balance of a person, community, or nation level. <![CDATA[SWINE WASTEWATER: IMPACTS ON SOIL, PLANT, AND LEACHATE]]> ABSTRACT: The use of animal-origin residues as a nutrient source without prior and proper investigations on their positive and negative impacts can affect the quality of agricultural soils and the environment into which they are inserted. In this sense, the aim of this study was to assess the impact of swine wastewater and mineral fertilization application on soil, soybean crop, and leachate characteristics. The experiment was developed in drainage lysimeters under field conditions. The following doses of swine wastewater were applied: 0, 100, 200, and 300 m3 ha−1, both with and without mineral fertilization. Swine wastewater application contributed to increasing soil nutrients; however, a special attention should be paid to Cu+ and Zn+ accumulation, which may interfere with soil quality in the long-term. In addition, Na+, K+, and N can be leached into groundwater and cause impacts on water quality. Wastewater supplied soybean crop requirements with some nutrients such as K+ and Zn2+, without the need for an additional mineral supplementation. Thus, once the above conditions are monitored, swine wastewater can be applied to soil. <![CDATA[ALTERATIONS ON THE EVAPOTRANSPIRATION OF SUGARCANE CULTIVARS UNDER DISTINCT SALINITY LEVELS APPLIED IN THE FERTIGATION]]> ABSTRACT: The aim of this research was to evaluate the effect of distinct levels of salinity on the evapotranspiration of the RB867515, RB855453, RB92579 and RB928064 sugarcane cultivars. The evapotranspiration was monitored during daytime period under meteorological conditions influenced, mainly by cloud variations. The salinity values were established by addition of 0, 50, 100 and 150 mM of Sodium Chloride (NaCl) to the nutrient solution, which was applied by fertigation, in such way that the electrical conductivity (EC) of the leached solution was near 3, 6, 10 and 13 dS m−1, respectively. The increase of the NaCl concentration in the nutrient solution affected, significantly and in a linear manner, the evapotranspiration of all sugarcane cultivars, such that the days with low cloud provided the highest evapotranspiration values and the greater reduction among salinity levels. Analysis of the evapotranspiration accumulated during the daytime period showed that there were no significant differences among sugarcane cultivars and that, under the highest atmospheric water demand, the evapotranspiration decreased 48.5 g plant−1 EC−1. This value represents the average reduction of 5.1% EC−1 when compared to the treatment without NaCl, considering data of all cultivars. <![CDATA[CROP COEFFICIENT REGIONALIZATION FOR IRRIGATED AGRICULTURE PLANNING IN MARANHÃO STATE -BRAZIL]]> ABSTRACT: Irrigated agriculture has emerged as a necessary technology to achieve greater productivity, mainly by supplying the water requirements of agricultural crops in critical periods, especially for those regions where natural rainfall is insufficient to meet these requirements. The daily water consumption of crops is strongly influenced by local weather conditions, which justifies the need for regionalized studies of the parameters influencing the water depth to be applied. The crop coefficient (Kc) is perhaps the most important parameter because it interferes directly with the crop water requirements. This index must be determined for each region, thus avoiding the use of reference values meant for other climatic conditions, causing loss of productivity The present study aimed to estimate the local crop coefficients for corn (Zea mays L.) for the climatic conditions of the State of Maranhão, aiming at the rational use of water in agriculture. The method, which allowed obtaining the local values of Kc for different phases of the crop cycle, used climatic data from 12 weather stations (INMET) and mathematical equations proposed by Albuquerque et al. (2001). It estimated the mean and final Kc values. The local values of Kc obtained for corn ranged from 0.73 to 0.77, 1.00 to 1.31, and 0.24 to 0.45 for initial, intermediate, and final phases, respectively. <![CDATA[INFLUENCE OF THE PLOTS FORMAT ON THE PERFORMANCE INDEX OF THE SOYBEAN COMBINE HARVESTER]]> ABSTRACT: The intensive mechanization during the harvest operation and success of this operation depends on several factors, one of which is the length and format of the plots. The aim of this study was to evaluate the operating performance of a soybean harvester in different geometric plots shape, using as quality indicators performance parameters by means of statistical control tools of process. The experiment was conducted in March 2014 in the city of Uberaba - MG. Operational capacity was evaluated in the mechanical harvesting of soybeans in three plots: irregular, rectangular and trapezoidal. Performance evaluations of soybean harvester were made from the following parameters: displacement speed, engine rotation, cylinder rotation and concave opening. The grain water contents affect the quality indicators of the soybean harvester performance in all plots shapes. The harvester performance is considered able to maintain between the specification limits and close to the target, to speed quality indicators the irregular and the trapezoidal plots and for cylinder rotation the trapezoidal plot. <![CDATA[DYNAMIC OF PRESSURE-DEFORMATION CURVE IN UNIAXIAL COMPRESSION TEST IN DIFFERENT LOAD TIMES]]> ABSTRACT: The loading application time by machinery tires and agricultural tires is one of the factors of soil compaction. We evaluated the effect of loading reduction time in uniaxial compression test, in laboratory, in some physical and mechanical parameters, approaching the loading field condition time by machinery with laboratory tests. Soil samples of two Oxisol and one Paleudult under different years of implementation of no tillage system (NT) and of different layers were collected and subjected to uniaxial compression tests, two times of loading application, 300 seconds per load, according to actual methodology and 30 seconds per load in the laboratory. We analyzed the soil deformation to each load, bulk density, pre-compression stress, recompress and compress indexes. Our results show that the reduction in the time of loading application can be introduced satisfactorily without changes at interested parameters. Furthermore, the soil deformation dynamic in the sample follow the elasto-plastic model used to determine the pre-compression stress, do not changing for the sigmoidal shape. <![CDATA[OPTIMIZATION MODEL FOR VEHICLE ROUTING AND EQUIPMENT REPLACEMENT IN FARM MACHINERY]]> ABSTRACT: An equipment replacement decision takes into account economic engineering models based on discounted cash flow (DCF) such as the Annual Equivalent Cost (AEC). Despite a large number of researches on industrial assets replacement, there is a lack of studies applied to farm goods. This study aimed at assessing an alternative model for economic decision analysis on farm machinery replacement, with no restrictions on the number of replacements and assessed goods during a defined timeline. The results of the hybrid model based on the combination of the vehicle routing problem and the equipment replacement problem (RVPSE) applied to three different farm tractors showed the model reliability, providing a wider range of decisions for management support. <![CDATA[DRYING KINETICS OF PEANUT KERNELS IN THIN LAYERS]]> ABSTRACT: The aim of this study was to adjust mathematical models to the experimental data on the peanut kernels drying in thin layer, as well as to determine the effective diffusion coefficient and the main thermodynamic properties involved in drying of the grains under different air conditions. The peanut kernels, with a water content of 0.59 ± 0.002 (dry basis, d.b.), were dried in a forced air ventilation oven with different temperature levels (40, 50, 60 and 70 °C) until reaching a water content of 0.04 ± 0.001 (d.b.). For the experimental data, eight mathematical models traditionally used to represent the drying kinetics of thin layer of agricultural products were adjusted, also being determined the effective diffusion coefficient and the thermodynamic properties, specific enthalpy and entropy and Gibbs free energy. The Diffusion Approximation, Two Terms, Midilli, Page and Thompson models represent the drying kinetics of peanut kernels in thin layers. The effective diffusivity increases with the increase of temperature, being the relation with the drying temperature described by the Arrhenius' equation. The increase in temperature promotes the decrease of the enthalpy and entropy values and the increase of the Gibbs free energy. <![CDATA[PHYSIC-CHEMICAL QUALITY OF SECOND CROP CORN AS A FUNCTION OF TIME BETWEEN HARVEST AND DRYING]]> ABSTRACT: The gap in the storage industry has brought a series of problems for the agro industrial market today, as its ability to directly infer the quality of newly collected material. The present study was carried out with the objective of evaluating the quality of second crop corn harvested with different water contents depending on the period until drying. The corn grains were harvested with moisture contents of approximately 28.5; 22.4; 21 and 19%, and subjected to temporary storage for ten days, simulating the time between harvest and drying. In the period, every two days the quality was evaluated by determining the specific mass, electrical conductivity, color, crude protein content, ethereal extract, ashes and carbohydrates. Based on the obtained results it is concluded that: the increase in the harvest water content negatively influenced the quality of the produced corn in the second harvest, being this effect worsened with time. The harvest moisture content of 19% is the least that affected the quality of the grains during 10 days of temporary storage. <![CDATA[COMPARATIVE ASSESSMENT BETWEEN PER-PIXEL AND OBJECT-ORIENTED FOR MAPPING LAND COVER AND USE]]> ABSTRACT: The traditional per-pixel classification methods consider only spectral information, and may be limited. Object-based classifiers, however, also consider shape and texture, firstly segmenting the image, and then classifying individual objects. Thus, a Geographic Object-Based Image Analysis (GEOBIA) was compared in conjunction with data mining techniques and a traditional per-pixel method. A cut of Landsat-8, bands 2 to 7, orbit/point 223/77, located between the municipalities of Cascavel, Corbélia, Cafelândia and Tupãssi, in the west part of the state of Paraná, from 12/18/2013 was used. In the GEOBIA approach was realized image segmentation, spatial and spectral attribute extraction, and classification using the decision tree supervised algorithm, J48. For the per-pixel method, we used the supervised Maximum Likelihood Classifier. Both approaches presented equivalent results, with Kappa Index of 0.75 and Global Accuracy (GA) of 78.97% for the approach by GEOBIA and Kappa Index of 0.72 and GA of 77.44% for the perpixel classification. The classification by GEOBIA showed better accuracy for the soil, forest and soybean classes, and did not show the splash aspect, which visually improves the classification result. <![CDATA[TOPOGRAPHIC ASPECTS IN THE SPATIAL AND TEMPORAL DYNAMIC OF NET RADIATION]]> ABSTRACT: The measurements obtained by remote sensing are influenced by issues related to relief. Based on that, this paper aims to analyze the spatial and temporal dynamics of the net radiation (Rn), considering the influence of topographic parameters on it, in Edgárdia Experimental Farm (FEE). It was used the methodology based on the SEBAL algorithm (Surface Energy Balance Algorithm for Land) to estimate the net radiation by orbital images. In order to assess the topographic influence on the computing of net radiation, three methodologies were applied: without topographic correction (RnSem), cosine correction (RnCos) and C correction (RnC). These methodologies were applied on 21 images of the orbital platform Landsat-5/TM, from 1985 up to 2010. Due to the complex relief of the FEE, the cosine correction did not show effectiveness on the attenuation of topographic influence. For the values of RnC, we noticed an average reduction of 5.97% for the standard deviation, relative to the images without correction. These results show the importance of considering the relief, to achieve higher accuracies on the estimation of biophysical parameters with orbital images. <![CDATA[OUTDOOR CULTIVATION OF <em>Scenedesmus obliquus</em> BR003 IN STIRRED TANKS BY AIRLIFT]]> ABSTRACT: The use of microalgae as a source of raw material for biofuel production has been highly targeted. Compared to other biological options for the capture and use of CO2, microalgae crops have the following advantages: high productivity, lack of competition with feed and food-based products, use of unproductive and non-arable land, and allowance of the use of wastewater for its cultivation. The use of wastewater from industrial, agricultural, and domestic sewage has been indicated as an alternative means to reduce the cost of crops, since such waste is generally released into the environment without previous treatment. This work addresses the use of petrochemical wastewater (ARP) from effluent produced at the Gabriel Passos Refinery (Petrobrás refinery unit) for the cultivation of a strain of Scenedesmus obliquus BR003. Twelve experimental units of 20 L each were constructed in the experimental area of the Biofuel Laboratory of the Federal University of Viçosa, Minas Gerais, Brazil in an uncontrolled environment, and the cultures were evaluated by quantification of total carbohydrates, total lipids, dry biomass, and growth evaluated by absorbance. The results showed that the wastewater from petrochemical effluent is an efficient growth medium for the growth of Scenedesmus obliquus BR003 microalgae for large-scale cultivation on land that is not suitable for other agricultural crops. <![CDATA[METHODOLOGY EVALUATION OF PIN MICRORELIEF METER]]> ABSTRACT: The effects of natural weathering and different managements performed in agriculture may best be understood by studying the soil roughness. The aim of this study was to evaluate the optimization of the use of pin microrelief meter, an instrument used to determine the soil surface roughness, as the number of readings collected over traditional methodology proposed in the bibliography. The study was conducted in Rio Paranaiba (MG), in a Haplustox soil. The experimental design was completely randomized in a 2×3 factorial design with four replications. There were combined two types of primary tillage: conventional tillage with disc plow (PCAD) and harrow (PCGA), and three amounts of readings (100, 200, and 300 reading points) sampled in each experimental unit. Independently of the soil tillage, disc plow and harrow, the collection of 100 readings using a pin microrelief meter of a square meter, was sufficient to determine the surface roughness before and after soil preparation, without accuracy loss compared with the traditional method. <![CDATA[DEVELOPMENT OF A TRACEABILITY MODEL APPLIED TO GOAT AND SHEEP MEAT PRODUCTION]]> ABSTRACT: The goat and sheep meat producer chain has developed in last years, thus, it is imperative to organize and structure the supply chain and to adopt reliable policies for products' traceability, as a tool to achieve these requirements. The study aimed to make a management program with a traceability model for goat and sheep meat production, with emphasis on ensuring product origin and management practices' transparency at the animal production unit. For this purpose, it was made a reference model in order to emit an origin certificate which, in turn, provides specific information concerning the final product from each unit. Secondly, the program was developed using Hipertext Preprocessor (PHP) technology and as for the Database Management System, it was used MySQL. The schematic model proposed meets the requirements of a traceability system for goat and sheep meat. Furthermore, the program can work as a tool for farm management, by reports and real-time remote access to information. <![CDATA[TECHNICAL EFFICIENCY AND IMPLEMENTATION COSTS OF SHEEP IDENTIFICATION SYSTEM]]> ABSTRACT: The objective of this research was to characterize the efficiency and convenience of sheep identification system and its implementation costs. Therefore we quantified the time for implementation, reading and data transfer to a management program in a manual system (earrings) and electronic system (subcutaneous transponders). Furthermore, it was evaluated the implementation costs of the traceability systems by analysis of the absorption costs and comparison between systems. It was observed that the implementation time for the manual system was shorter (2.2 s animal−1) than the electronic system (4.67 s animal−1). As for reading time, the electronic system presented shorter time (2.89 s animal−1) than the manual system (4.67 s animal−1). As for the data transfer time, the electronic system also presented shorter time (16 s) than manual system (6 min and 42 s). In terms of economic costs, the manual system presented lower implementation costs and lower values per tracked animal to ensure the economic viability. In conclusion, the producer must analyze the context around the production unit to choose the best traceability system.