Scielo RSS <![CDATA[Engenharia Agrícola]]> vol. 37 num. 1 lang. es <![CDATA[SciELO Logo]]> <![CDATA[COMPUTATIONAL FLUID DYNAMICS (CFD) APPLICATION FOR VENTILATION STUDIES IN BROILER HOUSES]]> ABSTRACT With the recent increase in the number of acclimatized broiler houses in Brazil, design and adaptation of facilities to withstand the tropical weather conditions enabling the maintenance of ideal conditions without increasing costs have been major challenges. The aim of this study was to evaluate the ventilation system in solid-wall broiler houses using computational fluid dynamics (CFD). The research was carried out in the city of Amparo - SP (Brazil). The facility consisted of a broiler house enclosed by masonry sidewalls with tunnel ventilation equipped with exhaust fans (air outlet) and cooling pads (air inlet). The following variables were collected: wind speed and dry bulb temperature over 27 equidistant points inside the house at bird height (0.30 m above the floor), wind speed in inlet – cooling pad, and static pressure in the outlet (exhaust fans) as a boundary condition. The data were monitored at the most critical time of the day – 2 pm during the final rearing stage in summer. The CFD technique allowed visualizing the air flow according to each running condition for exhaust fans, as well as determined the best setting of exhaust fans, avoiding a low air area renewal and turbulence. <![CDATA[DIFFERENT GENDER DIVISION PATTERNS FOR SWINE HOUSING IN WEAN-TO-FINISH SYSTEM]]> ABSTRACT This study aimed at identifying the best gender division pattern for swine at nursery stage, through the evaluation of behavioral and environmental parameters. Three treatments were established to achieve our objective: single-sex housing of 26 surgically castrated male pigs; mixed-sex housing of 13 castrated males and 13 females; and single-sex housing of 26 females. Environmental and behavioral data have been recorded. It was used an ethogram to make an inventory of behaviors and that was used in multivariate analysis. Bite addiction differed statistically among treatments, and the lowest occurrence was in mixed-sex housing. Results of the multivariate analysis suggested that regardless of the treatment chosen, relative humidity is positively associated with the production of gases and dry-bulb temperature with airspeed. Mixed-sex housing had multivariate relations suggesting less aggressive behaviors over food resources, being an example of social interaction that improves swine welfare. <![CDATA[<em>Hymenaea courbaril</em> SEEDLINGS IN PROTECTED ENVIRONMENTS AND SUBSTRATES]]> ABSTRACT The Brazilian copal is a tree fruit species that can be used for various purposes. The study evaluated protected environments and substrates in forming Brazilian copal seedlings (Hymenaea courbaril), at the State University of Mato Grosso do Sul, Cassilândia-MS, from January to March, 2014. Two greenhouses were used: (A1) agricultural greenhouse covered with aluminized thermal reflector screen of 50% shading and (A2) agricultural greenhouse covered with black screen of 50% shading. Inside the greenhouses, substrates derived from mixtures of cattle manure, soil, medium vermiculite, super fine vermiculite and washed fine sand were tested. For each cultivation environment, a completely randomized experimental design was used. The environments were compared by combined analysis. Emergence parameters, growth, phytomass and biometric relations were evaluated. The best seedlings were formed on the substrates containing 10 or 20% of cattle manure in the mix. Substrates containing 50% of cattle manure in the mixture did not favor the development of seedlings in the greenhouse with black screen. The best seedlings have been formed in the protected environment of aluminized screen coverage, with higher air and total phytomass, and Dickson quality index. Larger seedlings in height, with more leaves were formed in the protected environment with black screen coverage. <![CDATA[THERMAL ENVIRONMENT OF TABLE GRAPE PACKING HOUSES IN THE SÃO FRANCISCO VALLEY]]> ABSTRACT The aim of this study was to characterize the thermal environment of the sorting and packing sectors of small, medium and large packing houses in the São Francisco Valley, Northeast of Brazil. Micrometeorological data were monitored every 15 minutes for 20 days during winter 2014 and summer 2015. The parameters evaluated were air temperature (°C), relative humidity (%) and radiant thermal load, RTL,(W/m2). External environmental data were obtained from weather stations close to the packing houses. The data obtained show that packing houses minimum and maximum temperatures were reached at 6am and 3pm, respectively, during winter and summer. Both seasons had air temperatures above 20°C, relative humidity below 90% and radiant thermal load above 450 W/m2. The construction materials that had the highest energy transmissions were the roofs. Metal roofs had the worst thermal conditioning, resulting in maximum internal air temperatures of 32.7°C and minimum relative humidity of 40.9% at 3pm, during summer. According to the results, thermal environments of sorting and packing sectors proved to be inadequate for processing table grapes, mainly during summer. These packing houses should be modified to reach the optimal thermal environment, considering the regional climatic conditions. <![CDATA[KALE SEEDLINGS PRODUCTION IN DIFFERENT SUBSTRATES, CELL VOLUMES AND PROTECTED ENVIRONMENTS]]> ABSTRACT The kale is a brassica, this vegetable presents importance on nutritional and economic patterns. The present study aimed to evaluate the effect of different substrates, trays and protected environment in the formation of kale seedlings. The experiment was conducted in two greenhouses located at the State University of Mato Grosso do Sul - MS. The first environment consisted of an agricultural greenhouse with polyethylene film cover, while the second was an agricultural nursery with monofilament screen and mesh to offer 50% of shading. In each protected environment were used 72 and 128 cells tray and six different compositions of substrates with organic material based on cassava branches (CB) and cattle manure (CM): 1) 100% CM; 2) 20% CM + 80% CB; 3) 40% CB + 60% CM; 4) 60% CB + 40% CM; 5) 80% CB + 20% and CM; 6) 100% CB. The seedlings were evaluated according to the parameters: dry mass of seedlings, stem diameter and plant height. The agricultural nursery was the most suitable for the formation of kale seedlings, with 72 cells tray and the substrate composed of organic matter with 20% of cassava branches and 80% of cattle manure. <![CDATA[REGIONALIZATION OF MAXIMUM AND MINIMUM FLOW IN THE TELES PIRES BASIN, BRAZIL]]> ABSTRACT In a watershed there is space and climate variability within its catchment area, causing changes in water qualitative and quantitative characteristics. Thus, the hydrological data collected from a specific basin may be extrapolated to neighboring basins with similar physical characteristics, using techniques of hydrological regionalization. This study developed the flow regionalization in the Teles Pires Basin, using historic series and probabilistic models to verify the data adherence through the regression equations adjustment according to the hydrologically homogeneous regions. The linear and power regression models were tested, employing physical and climatic characteristics and then the best adjustments were selected based on coefficients of determination, adjusted coefficient of determination, significance by F-test and small number of variables in the equation. The physical characteristics of the basin, drainage area and mainstream length, and the climatic variable, annual total precipitation showed higher adjustments. These equations can provide subsidy for decision making in the process of water resource management. <![CDATA[DETERMINATION OF XARAÉS GRASS QUALITY SUBMITTED TO IRRIGATION WATER LEVELS AND NITROGEN AND POTASSIUM DOSES]]> ABSTRACT In the correct pasture management, nutritional factors such as nitrogen and potassium fertilization play an important role in the forage production and quality. The aim was to evaluate the effects of the application of water levels, nitrogen and potassium doses in the Xaraés grass in the south of the State of Tocantins. For this, Xaraés grass was cultivated in the experimental field of the Federal University of Tocantins, municipality of Gurupi, TO. We used a mixture of fertilizer, combinations of N and K2O following the 1 N: 0.8 K2O ratio. To evaluate the effect of irrigation water levels and combinations of N and K2O doses in Xaraés grass, the plant height, the crude protein content and neutral detergent fiber were determined. The greatest height observed in the grass was 61.6 cm, with the dose application of 700 kg ha-1 yr-1 of N: 0.8 K2O and a water level of 120% of the ETc. The highest protein content was 11.7%, with the highest dose application of fertilizer and absence of irrigation. The highest fiber content in neutral detergent was 64%, with the estimated amount of 385.5 kg ha-1 yr-1 of N: 0.8 K2O and a water level of 120% of ETc. The conclusion was that the plant height, fiber detergent and crude protein content were influenced by the change in water level of irrigation and fertilizer doses. The values of plant height and crude protein increased with the increase of water levels and manure dose, while the fiber content of neutral detergent decreased with the increase of irrigation and varied little with the increase of fertilizer dose. <![CDATA[GÁLIA MELONS PRODUCTION IN PROTECTED ENVIRONMENT UNDER DIFFERENT IRRIGATION DEPTHS]]> ABSTRACT The study aimed to evaluate the “Gália” melons productive characteristics grown in greenhouse under different irrigation levels, and conducted with and without soil cover by plastic mulching. Experiments I (WC) and II (WtC) were conducted simultaneously in a protected environment, using a completely randomized design (CRD), where plants of Gália melons (Hybrid Nectar cv.) received five levels of water depth defined by 50, 75, 100, 125 and 150% of evapo-transpiration (water requirement), with four replications, differing only by utilization (WC) or not (WtC) of plastic mulching. The results showed that the variables productivity, average weight, length and diameter of the fruits were affected by different levels of water replacement in the soil regardless the use or not of the soil cover. The largest reductions in productivity 46.32 and 32.03% were observed for the treatment of 50%, compared to the treatment of 100% for experiments I (WtC) and II (WC), respectively. <![CDATA[APPLICATION OF OPTICAL METHOD IN MEASURING MECHANICAL VIBRATIONS IN A CANTILEVER BEAM]]> ABSTRACT The pertinent literature discloses a family of optical profile measuring techniques highlighting the moiré methods. The Moiré technique is based on the interference of two superimposed optical grids which produce fringe patterns which can be processed to analyze the DYNAMIC MEASUREMENT IN MATERIALS mechanical behavior. The goal of this research is to experimentally determine the mechanical displacement of a slim cantilever beam by means of Moiré technique with Phase Shift. Photomechanical experimental arrangement included a digital camera, a multimedia projector and a PC. The occurrence of oscillations has been adequately analyzed. The results showed data from which useful information can withdraw, being of great importance to support agricultural machinery projects and development. <![CDATA[PERFORMANCE OF AN AGRICULTURAL DIESEL ENGINE USING DIFFERENTS FUELS]]> ABSTRACT The use of fuels for agricultural Diesel engines cycle, both of mineral origin (Diesel) or vegetable and animal origin (biodiesel) can significantly alter its performance. Therefore, the aim of this study was to quantify the change in torque, power and consumption of agricultural Diesel engine fuel using minerals and vegetables fuels. It was used a tractor power take-off coupled to a magnetic brake dynamometer (for measuring speed and torque for subsequent calculation of power), and a flow meter (for measuring the hourly fuel consumption and specific fuel consumption calculation). Eleven different fuels (S10 mineral diesel with 5%, 10%, 15%, 20% and 50% biodiesel and mineral diesel S500 with 5%, 10%, 15%, 20% and 50% biodiesel, have been used pure biodiesel B100). The results indicate that the increase of biodiesel in mineral diesel reduces torque and power, increases the specific fuel consumption and practically does not change the hourly consumption. This reduction in torque and power occurs with greater intensity in Diesel S10. Additions of 10% biodiesel in mineral diesel reduces the maximum torque 1.65 Nm (0.6%), the maximum power at 0.33 kW (0.6%) and increases the specific fuel consumption of 3.6 g kWh -1 (1.3%). <![CDATA[AGRONOMICAL ATTRIBUTES OF SOYBEANS AND SOIL RESISTANCE TO PENETRATION IN NO-TILLAGE AND CHISELED SURFACES]]> ABSTRACT Farming systems may affect soil properties and crop production of components, decreasing yields. This study aimed to assess penetration resistance (PR) and agronomic traits of soybeans under no-tillage (NT) and chiseling (CP). The experiment was carried out in a randomized block with two treatments (tillage and scarification) with 12 repetitions; yet soil penetration resistance (PR) was assessed in a factorial block, considering farming systems and sampling sites (row and interrows). PR was measured with an impact penetrometer, sampling in row and interrows within a 22.5 x 0.1 m2 mesh grid up to 0.60 m depth. The obtained values were higher for NT in the 0.10-0.20 m layer. Great PR values in interrows were only registered within the surface layer. This is because there was no soil mobilization by seeder chisel plow. In chiseled soil, compaction was reduced, however, the first tractor passings were able to compact the soil to a depth of 0.50 m. Therefore, scarification reduced the plant stand and penetration resistance, allowing greater growth and soybean yield. <![CDATA[TIMES OF EFFICIENCY AND QUALITY OF SOYBEAN CROP MECHANICAL OPERATION IN GEOMETRY FUNCTIONS OF PLOTS]]> ABSTRACT The knowledge of the operational quality of soybean harvester provides useful information to management in order to obtain the maximum performance of all available resources, with minimal expenses. The aimed of this study was to evaluate the quality of mechanized soybean harvesting operation in different formats of plots through statistical process control. Treatments were established from the formats of existing plots in the area (irregular, trapezoidal and rectangular). The activities carried out during the harvest were monitored (harvesting, unloading, handling, maneuvering and climate charts) and through these activities were made the calculation of capacity and harvesting operation efficiencies. In the determination of total losses were used 4 circular frames of 0.33 m2 each, the grain losses were considered below and above these frames. The statistical analysis was by means of statistical process control opting for the use of the type CUSUM charts. The rectangular plot showed greater management efficiency and harvesting efficiency. The trapezoidal shape facilitated the maneuvers relative to others. The rectangular plot has better quality of operation in relation to others. The CUSUM control chart showed to be effective in preventing instability and maintenance of process quality. <![CDATA[AERIAL AND GROUND APPLICATION OF FUNGICIDE IN CORN SECOND CROP ON DISEASES CONTROL]]> ABSTRACT The aim was to evaluate the diseases severity on corn second crop. The research was conducted on the agricultural year of 2013 and 2014, evaluating the application quality over the fungicide spraying. The hybrid used was PIONEER 30k75 BT HERCULEX, evaluating the diseases severity previously and after the fungicide spraying, spray deposition on the culture and productivity. The aerial application was carried out with solution volume of 7.5, 13.5, 20 and 30.3 L ha-1, using automatic rotating nozzles, and the ground application with 90, 110, 130 and 150 L ha-1, uniform flat spray tips. As control a non-fungicide treatment was used. The aerial and soil treatment showed diseases control from the corn crop, being the biggest cover of drops acquired at the volumes 30.30 L ha-1 for aerial and 150 L ha-1 for soil, with no significant change on the productivity of the corn harvest for both forms of spraying: aerial or soil. <![CDATA[QUALITY OF SEED DISTRIBUTION AT DIFFERENT SPACES BETWEEN BASE AND INTERMEDIATE BASE]]> ABSTRACT The aim of this study was to analyze the influence of space between the base and intermediate base on quality of seed distribution with a horizontal seed plate. The experiment was carried out in 2012 at the Laboratory of Agricultural Mechanization of the State University of Ponta Grossa - PR, Brazil, using a sowing simulation device. The experimental design was completely randomized design with four treatments and seven replications. Treatments consisted of spaces (0, 1, 2, and 3 mm) between the base and intermediate base. Replications were defined by 250 spacing between seeds. Corn (Zea mays L.), soybean (Glycine max L. Merrill), and sorghum (Sorghum bicolor Moench) seeds were tested. The analyzed variables were faulty, multiple and acceptable spacing. By increasing the space between base and intermediate base, quality of seed distribution was reduced for all species. <![CDATA[ESTIMATION OF FUEL CONSUMPTION IN AGRICULTURAL MECHANIZED OPERATIONS USING ARTIFICIAL NEURAL NETWORKS]]> ABSTRACT This study aimed to develop artificial neural networks for the estimation of tractor fuel consumption during soil preparation, according to the adopted system. The multilayer perceptron network was chosen. As input data: the soil mechanical penetration resistance, the mobilized area by implements, the working gear and the tractor engine speed. The number of layers and neurons varied to form different architectures. The adjustment was verified based on various statistical criteria. The values estimated by the networks did not differ significantly from those obtained experimentally. The conclusion was that the networks showed adequate reliability and accuracy to predicting the fuel consumption in each tillage system, in function of the input data and this can be a useful tool for planning and management of agricultural operations. <![CDATA[STARCH EXTRACTION FROM THE PEACH PALM (<em>Bactris gasepaes</em> Kunth.) FRUIT: A MODEL APPROACH FOR YIELD INCREASE]]> ABSTRACT The objective was to study the starch extraction process of the peach palm (Bactris gasipaes Kunth.) fruit focused on increasing yield and in preserving the quality characteristics the extracted product. Two experimental designs are carried out in order to investigate the effects of NaOH and NaHSO3 concentrations, as well as the decantation time, on the yield of starch and on product color. Firstly, a 23 full factorial design provided a linear model with 95% of confidence, indicating major tendencies for optimization. Secondly, a 22 central composite design rendered a quadratic model which allowed the maximization of yield (it 9.0% higher) without compromising the color of the product. The maximum yield of 23.90%, validated with triplicate experiments, is considerably higher than the yield of starch from other fruits reported in literature. <![CDATA[HYDROGEN PRODUCTION AND PERFORMANCE OF ANAEROBIC FIXED-BED REACTORS USING THREE SUPPORT ARRANGEMENTS FROM CASSAVA STARCH WASTEWATER]]> ABSTRACT Fixed-bed reactors have been considered promise alternatives for hydrogen production due to their simple construction and increase in the biomass retention. The purpose of this study was to investigate the biological production of hydrogen in anaerobic fixed-bed reactors with cassava starch wastewater used as substrate. Different support materials and arrangements of fixed-bed were used to evaluate the biological production of hydrogen in anaerobic continuous fixed-bed reactors, with cassava starch wastewater as substrate - recycled low-density polyethylene scraps, in packed bed (R1), recycled low-density polyethylene cylinders, in ordained bed (R3) and bamboo stems, in vertical arrangement (R2 and R4). In R1 the initial pH was adjusted for 6.0, with hydraulic retention time (HRT) of 4 h and organic loading rate (OLR) of 9.5 g.L−1.d−1. In R2 the initial pH was maintained in 4.5, with HRT of 4 h and OLR of 9.5 g.L−1.d−1. R3 and R4 were operated with initial pH of 4.5, HRT of 4 h and OLR of 13.5 g.L−1.d−1. The volumetric hydrogen production (VHPR) was favored by lower OLR applied, evenin different pH ranges (6.0 and 4.5). VHPR values of 229 mL H2.L−1.d−1and 248 mL H2.L−1.d−1 were obtained in R1 and R2, respectively. Both in the bamboo stems bed as in the polyethylene cylinders bed, the increase of OLR and the reduction of the initial pH resulted in a diminishing of VHPR to 175 mL H2.d−1.L−1 (R3) and 145 m LH2 .d−1.L−1 (R4). Higher concentrations of butanol (821.32 and 1,529.22 mg.L−1) and ethanol (915.41 and 924.41 mg.L−1) were verified in the reactors with bamboo stems. In R4, the increase of OLR and the reduction of the initial pH contributed to the increase of butanol concentration in 1.8 times, diminishing the VHPR in 41.68%, yield in 63.95% and H2 in 37.6%, and indicating that the effect of pH is more pronounced with the increase of OLR, leading to the solventogenesis. <![CDATA[PERFORMANCE OF ESTIMATIVE MODELS FOR DAILY REFERENCE EVAPOTRANSPIRATION IN THE CITY OF CASSILÂNDIA, BRAZIL]]> ABSTRACT Before choosing the method of the estimate of reference evapotranspiraton (ET0) in a region, it is important to evaluate the degree of precision of the model. The present research aimed to evaluate the performance of 30 methods for daily ET0 estimate in the Cassilândia city, Brazil. The meteorological data had been obtained from the National Institute of Meteorology in the period of four years (from April, 2008 to March, 2012). As standard method it was chosen the Penman-Monteith-FAO56, and the comparison of the results was by means of the estimated standard error (ESE), the determination coefficient (R2), the coefficients “a” and “b” of the linear regressions, Willmott's index of agreement (d), Pearson's correlation coefficient (r) and the reliable coefficient (c). The best methods for estimate the daily ET0 had been: Penman-Original, Stephens-Stewart, Abtew, Thornthwaite-Modified, Priestley-Taylor, Penman-FAO 24, Hicks-Hess, Liquid-Radiation, Turc, Hamon, Camargo, Temperature-Radiation, Global-Radiation and the Original Hargreaves. When it has been given only temperature data, the Camargo method is the more recommended. The methods Blaney-Criddle-FAO 24, Radiation-FAO 24, Makkink, Hargreaves-Samani, Jensen-Haise, Linacre, Ivanov, Kharrufa, Garcia-Lopez, Blaney-Morin, McCloud, McGuiness-Bordne, Romanenko, Lungeon, Tanner-Pelton and Thornthwaite should not be used to estimate the daily ET0. <![CDATA[DATA MINING FOR THE ASSESSMENT OF MANAGEMENT AREAS IN PRECISION AGRICULTURE]]> ABSTRACT Precision Agriculture (PA) uses technologies with the aim of increasing productivity and reducing the environmental impact by means of site-specific application of agricultural inputs. In order to make it economically feasible, it is essential to improve the current methodologies as well as proposing new ones, in which data regarding productivity, soil, and compound indicators are used to determine Management Areas (MAs). These units are heterogeneous areas within the same region. With these methodologies, data mining (DM) techniques and algorithms may be used. In order to integrate DM techniques to PA, the aim of this study was to associate MAs created for soy productivity using the Fuzzy C-means algorithm by SDUM software over a 9.9-ha plot as the reference method. It was in opposition to the grouping of 2, 3, and 4 clusters obtained by the K-means classification algorithms, with and without the Principal Component Analysis (PCA), and the EM algorithm using chemical and physical data of the soil samples collected in the same area during the same period. The EM algorithm with PCA modeling had a superior performance than K-means based on hit rates. It is noteworthy that the greater the number of analyzed MAs, the lower the percentage of hits, in agreement with the result shown by SDUM, which shows that two MAs compose the best configuration for this studied area. <![CDATA[LOW COST <em>FUZZY</em> SYSTEM APPLIED TO THE CONTROL AND SUPERVISION OF THERMAL ENVIRONMENT IN POULTRY FARMS]]> ABSTRACT The aim of this study was to develop an automated fuzzy controller with microcontroller, consisting of hardware and software for the control and supervision of thermal environment in broiler farms. The study has been conducted in two steps: in the first one it was performed a computer analysis through simulation. In the second step it was performed the evaluation of the software and hardware developed by the equipment test in the registration of the thermal environment variables within the facility and activation of the climate control equipment. The experiment was conducted in a poultry house with broilers of Cobb 500 lineage, aged between 1 and 28 days in an experimental farm located in Bambuí - MG. The presented prototype is able to operate in an automatic way, the equipment control for the ambience in poultry farms and supervision of meteorological variables. The developed fuzzy controller estimated satisfactorily the thermal comfort for the poultry during 28 days of experiment, keeping the thermal parameters within the specified by literature. The system can be used in the automation of ambience equipment for the four steps of the production chain for broiler chickens.