Resumo em Inglês:

ABSTRACT The selection of the type of fuzzy systems pertinence curve allows a better representation of the mathematical model and a smaller simulation error. We aimed to study the effect of pertinence curves in fuzzy modeling of broiler performance, created in different production systems. For the development and testing of fuzzy models, three commercial aviaries (conventional, tunnel with negative pressure, and dark house) were evaluated over one year, totaling six lots per system. For the development of the model, the input variables were enthalpy in each rearing phase (initial: phases 1, 2, and 3; growth: phase 4; and final: phase 5) and the output variables were feed intake (FE), weight gain (GP), feed conversion (FE), and the productive efficiency index (PEI). Triangular, trapezoidal, and Gaussian pertinence curves were combined and applied to represent the input and output fuzzy sets, totaling nine fuzzy models for each output variable. The combinations of pertinence curves provided adequate responses for the prediction of AL, GP, RC, and PEI. However, the selection of the types of curves should be studied on a case-by-case basis, so that the smallest possible simulation errors are obtained.

Resumo em Inglês:

ABSTRACT This study aimed at evaluating bovine behavioral parameters managed in crowding pens built with modular panel of reforestation wood and homogeneous particle sheets of sugarcane bagasse and in conventional wooden crowding pens. The animals treated had their body surface temperature measured by the infrared thermography method and the behavior evaluated through the flight time parameters and the behavior score in the crowding pens. The results indicated that the animals managed in these buildings showed no difference in the behavioral parameters, but the mean and maximum superficial body temperatures were lower in the animals managed in the crowding pens of modular panel.

Resumo em Inglês:

ABSTRACT The success of confinement for dairy cattle in the compost barn model depends mainly on the management of the bed and consists of its turning. This paper characterises the spatial variability of the bed temperature in the compost barn confinement model, as well as verifying whether there was an effect on efficiency from turning the bed with different agricultural implements. The experiment was conducted during the summer and winter of 2016, with 8 days of collection in each period. Data were analysed with descriptive statistics methods and geostatistical modelling with semivariograms and kriging maps. The results of the t-test at a5% significance level indicated that, after turning the bed with the plough or rotary hoe, the temperature values were significantly lower. There was an efficient on bed turning based on different agricultural implements. Spatial dependence was observed on the data, with a better adjustment given by a Gaussian model. Kriging maps allowed the characterization of the spatial variability of bed temperature and the visualization across the compost barn bed at the superficial layer and 0.15 m in depth.

Resumo em Inglês:

ABSTRACT Different techniques have been used to evaluate the energetic characteristics and damage to the photosynthetic apparatus of plants exposed to different stresses, including the measurement of chlorophyll fluorescence. The objective of this study is to evaluate the photosynthetic response by assessing the fluorescence parameters of chlorophyll a in basil (Ocimum basilicum L.) cv. Alfavaca Basilicão cultivated in a hydroponic deep-flow technique system using treated domestic wastewater. The study used a completely randomized block design with a 2 × 2 factorial scheme, in which the factors were the water source used for preparing the nutrient solution (tap water or treated domestic wastewater) and the height (upper and lower) of the platform of the cultivation system. The photosynthetic yield of the plants grown on the lower platform was comparatively lower regardless of the water source. However, there was no significant effect of the water source on the potential and effective quantum yields of photosystem II, indicating the absence of changes in the photosynthetic apparatus and photosynthetic yield of plants produced with treated domestic wastewater, suggesting the viability of this treatment for producing basil cv. Alfavaca Basilicão in hydroponic systems.

Resumo em Inglês:

ABSTRACT It was used statistical techniques for the evaluation of agricultural experiments, but there are mathematical theories that allow finer adjustments, highlighting among them, the fuzzy logic. The objective of the study was characterizing a method of fuzzy modeling from an agronomic experiment. For this study it was used data from an experiment conducted at the School of Agriculture of São Paulo State University (UNESP) in Botucatu-SP. The system input variables based in fuzzy rules were soil water tension and doses of water salinity, being defined three fuzzy sets. The output variables was elected from the biometric and productivity analysis that showed statistically significant differences, namely, plant height, stem diameter, leaf area, green biomass, dry weight, number of fruits, average fruit weight and percentage of disabled fruits. For output variables 9 fuzzy sets were defined. From the adopted methodology, the model allowed extract directly from the data set a base of rules without the use of questionnaires to experts for its preparation. In addition, it will analyze intermediate regions at trial levels and weave other conclusions of the tomato growth and productivity, not limiting in this way only those observed with statistical analysis.

Resumo em Inglês:

ABSTRACT Tomato, the most popular greenery, is characterized by being a demanding crop in water and when in prolonged and severe drought, has limitations in its growth and reduction in productivity. In addition, this vegetable is affected by excess salinity in the water, which causes leaf wilting, apex and leaf edges burn until their death. Such effects generally are studied using statistical analysis, but there are mathematical theories that allow finer adjustments, highlighting among them, the fuzzy logic. The objective of this study was to evaluate the effects on the growth and yield of hybrid tomato from different water tensions in the soil and different salinity doses in the irrigation at 120 days after sowing using fuzzy modeling. It was used data from an experiment that was conducted in the experimental area at the School of Agriculture of São Paulo State University (UNESP) in Botucatu-SP. The input variables of the fuzzy systems were irrigation and salinity, while the output variables elected were the biometric analysis and productivity that showed statistically significant differences. Analyses of the effects of irrigation and salinity were performed by means of three-dimensional graphics and the output variables contour maps. The variables studied here showed higher values, with exception of plant height for treatment with irrigation in field capacity and water salinity zero.

Resumo em Inglês:

ABSTRACT The association of adjuvants with phytosanitary products has been tested for several years but is commonly recommended without considering technical and scientific criteria. This study aimed to evaluate the influence of the association of insecticides with different adjuvants on surface tension, contact angle, coverage, hydrogen ionic potential (pH), and the formation of deposits exposed to rain. The insecticides thiamethoxam, imidacloprid, and lambda-cyhalothrin were tested at doses of 75 g ha−1, 150 g ha−1, and 150 g ha−1, respectively, with a spray volume of 200 L ha−1. Break-Thru 240®, Break-Thru 233®, Break-Thru Union®, Oleo FC Agraröl®, and Naturo'il® were added to each of these spray solutions. The results showed that the addition of adjuvants reduced the surface tension and contact angle, and consequently, increased droplet coverage. No deposit pattern was found in the thiamethoxam, imidacloprid, and lambda-cyhalothrin insecticides associated with the adjuvants and a higher amount of residue was observed on wheat leaves than on maize leaves. The use of adjuvants can be an alternative to improve the efficiency of insecticides, allowing the product to achieve its full control potential.

Resumo em Inglês:

ABSTRACT The global navigation satellite system (GNSS) is the basis for localized crop management by allowing the georeferencing of collected data and the generation of maps by different systems that compose precision agriculture. There is a demand for low-cost navigation systems to enable their use in agriculture. Therefore, the objective of this study is to integrate a low-cost GNSS module to a single-board computer using Kalman filtering to obtain navigation data. The system was evaluated by performing one static and two kinematic experiments, with three repetitions each. In the static experiment, the mean error was 3.25 m with a root mean square error (RMSE) of 3.73 m. In the first kinematic experiment, data variability was lower at a velocity of 1.39 m s−1. In the second kinematic experiment, the mean error was 1.26 and 1.13 m, and the RMSE was 1.45 and 1.27 m for data obtained before and after filtering, respectively. In conclusion, the system reduces the lateral errors in linear sections but is not indicated for sections that change direction. Moreover, this system can be used in agricultural applications such as soil sampling and crop yield monitoring.

Resumo em Inglês:

ABSTRACT Cryopreservation is a technique used to preserve genetic material at ultra-low temperatures in cryogenic germplasm banks. In order to enable the cryopreservation of a seed, it is necessary to study its appropriate freezing temperature and its water content, because seeds reach maximum physiological quality with high water contents, and they tolerate drying when they are orthodox seeds, but they may not tolerate cryopreservation. Therefore, the objective of this study was to analyze the influence of initial water content (50 to 10% wet basis) on the kinetic behavior of the lima bean seed at the temperature of −150 °C, in addition to determining changes in its physiological quality (germination and vigor) when cryopreserved (−150 °C) for 30 days with the variation of initial water contents (50 to 10% wet basis). For this purpose, changes in lima bean size (length, width, and thickness), sphere-equivalent radius and volume, and kinetics of seed cryopreservation as a function of its water content. The Fourier model and the Cavalcanti-Mata & Duarte models I and II were used for cryopreservation modeling, in addition to proposing a new model for cryopreservation kinetics in which water content determines the kinetic behavior. The conclusion was that the water content of 10% wb should be used for the lima bean seed cryopreservation since its physiological quality was not affected by cryopreservation at −150 °C. The model that best represents the experimental data is Cavalcanti Mata & Duarte Model II.

Resumo em Inglês:

ABSTRACT The commercial sector of starch extraction has fully automated plants with a minimum scale of 200 ton.day–1, which extracts starch from maize and cassava in Brazil. Although these starches are commodities, the market demands starches with special properties obtained without chemical modifications. A higher-priced starch can compensate for small-scale extraction, as in the case of arrowroot starch, which would correspond to an alternative income for the producer. As a small-scale equipment was not available in Brazil, it was necessary to adapt a hammer mill for arrowroot starch extraction, which should have a performance similar to that obtained from cassava roots using industrial grinders. The degree of disintegration and energy consumption were adopted as the efficiency indexes. The hammer mill was equipped with two perforated plates. The results showed that use of an adapted hammer mill provides an average diameter of 74.64 ± 0.09 μm for perforated plate 1 (TP1) and 76.62 ± 0.06 μm for TP2; these results were equivalent to those obtained with cassava in the respective perforations which, in turn, was comparable to the degree of grinding obtained with large industrial equipment. The specific energy consumption needs for arrowroot disintegration varied from 31.47 to 48.91 kJ.kg–1, which was considered close to that calculated for large-scale industrial cassava roots grinders, reported at 37.03 kJ.kg–1.

Resumo em Inglês:

ABSTRACT The goal of this study was to use the spatial bootstrap method to model the spatial dependence structure of soybean yield and soil chemical attributes in an agricultural area. The study involved developing confidence intervals in probability plots to determine the probability distributions assumed by the data; determine the empirical distributions of the semivariances and model parameters, allowing to obtain statistics and confidence intervals; and to construct maps for the variables. The quantile-quantile plots indicated that the data follows a normal distribution. The confidence intervals for the semivariances helped to model the spatial dependence structure, and the descriptive statistics of the bootstrap replicates of the model parameters allowed to test the consistency of the estimates. The soil chemical attributes (calcium, potassium, and organic matter) were at levels suitable for soybean cultivation. However, the pH was below the ideal range in most of the study area, and water stress during cultivation decreased the mean yield. Therefore, according to the results, a recommendation to the farmer is to correct the soil pH to increase the yield.

Resumo em Inglês:

ABSTRACT Ground Penetrating Radar (GPR) is a geophysical method that uses electromagnetic waves to study subsurface structure in different fields such as geology, agriculture and civil engineering. The wave penetration in the soil is strongly controlled by the electrical conductivity of soil components such as clay, organic matter, and water. In this study, tests were conducted in a floodplain in the Elizabeth Creek watershed (New Jersey – USA). We established one transect where measurements were completed using two techniques, common mid point (CMP) and constant offset profile (COP), both with 100- MHz frequency antennas. Measurements were also completed using 250 and 500 MHz shielded antennas. GPR showed good accuracy to study soil spatial variability and stratigraphy. Antennas of a higher frequency had less vertical investigation capacity and greater accuracy. In this study, it was not possible to clearly differentiate signals from organic matter and clay; this was the main limitation of the GPR system.

Resumo em Inglês:

ABSTRACT Wood is one of the main materials used in the constructing of covering structures (roofs) because of its versatility. Under this situation, due to solar radiation incidence, the temperature can exceed 60 °C and, such as other environmental conditions, influence the mechanical properties of the wood in use. The aim of this research was to study the influence of exposure time of the wood of four different hardwood species at a temperature of 60 °C on the shear strength parallel to fibers. The wood of the following species was used: Cupiúba (Goupia glabra), Eucalyptus (Eucalyptus saligna), Garapeira (Apuleia leiocarpa), and Jatobá Tamarindo (Hymenaea sp.). In order to investigate the effect of exposure time (0, 168, 456, 720, and 2160 hours) of the wood species in an oven (60 °C) on the values of shear strength in the direction parallel to fibers, an analysis of variance (ANOVA) was carried out at 5% significance level. According to the results, the time the wood was exposed to the operating temperature significantly influenced the shear strength in the direction parallel to fibers. In addition, all species showed a decrease in shear strength after 456 hours of exposure at a constant temperature of 60 °C.

Resumo em Inglês:

ABSTRACT Wind solicitations generate horizontal, tensile, and compressive stresses on building foundations. In empty light structures, such as agricultural greenhouses and, in the specific case of silos and elevated structures such as metal water tanks, the consideration of these loads becomes important because the lack of the weight component due to the storage load significantly influences the balance of forces. This study focused on the behavior of metallic steel profiles, aiming at its application as a foundation element for the pile, considering the soil of Diabasic origin common to the Center-South region of Brazil. Load tests in real scale were carried out on three steel profiles, type I, gauge W 250 mm x 32.7 kg m-1, drilled in the ground up to 12m deep by means of a pile driver. One steel profile was submitted to lateral loading, another to vertical compressive loading, and the other to vertical tensile load. Test results determined the bearing load of the pile for each loading type, calculated the soil reaction coefficient for lateral loading, and verified the applicability of load capacity prediction methods to tensile and compressive strengths of piles, commonly used in foundation projects.

Resumo em Inglês:

ABSTRACT Accurate crop data are essential for reliable irrigation water requirements (IWR) calculations, which can be acquired during the crop growth season for a given region using earth observation (EO) satellite time series. In addition, a relationship between crop coefficients and the NDVI can be established to allow for crop evapotranspiration estimation. The main objective of the present work was to develop a methodology, and its implementation in an application software, to extract crop parameters from EO image time series for a set of parcels of different types of crops, to be used as input data for a soil water balance model to compute IWR. The methodology was tested at two distinct test sites, the Vila Franca de Xira (site I) and Vila Velha de Ródão (site II) municipalities, Portugal. Landsat-7 and −8 images acquired from April to October 2013 were used for site I, while SPOT-5 Take-5 images from April to September 2015 were considered for site II. EO data were used to estimate the basal crop coefficients, planting dates, and crops growth stage lengths. Based on crop, soil and meteorological data, the IWR for the main crops of both test regions were estimated using the IrrigRotation model. The crop coefficient curves obtained from the EO data proved to be reliable for IWR estimation.

Resumo em Inglês:

ABSTRACT This article aimed to select items with which to evaluate the ergonomic and safety conditions in tractors used by smallholders and family farmers, based on standardization research and legislation for the sector. Brazil has a comprehensive set of technical standards and legislation for the agricultural machinery sector intended to guarantee product standardization and to promote the health and safety of the users. Therefore, the initial step of this research was to review the technical norms and legislation for the product in order to develop instruments to assess their ergonomic and safety conditions. Twenty-eight Brazilian Technical Standards (NBR) and four Regulatory Norms (NRs) were investigated, in addition to CONTRAN (the Brazilian Traffic Council) Resolution No. 227/2007, which establishes requirements for vehicle lighting and signaling systems, generating 57 safety evaluation items and 35 ergonomic items. These evaluating items were applied to six tractor models commonly sold to smallholders with a rated engine power of 37–57kW. The results indicate levels of safety unconformities as high as 39.7% for the worst case and 44.7% ergonomic-related problems for the same tractor model. These data point to the need for improvements, especially in lower power tractors.

Resumo em Inglês:

ABSTRACT In agricultural areas with a historical of systematic soil sampling, alternative methodologies such as directed sampling design based on management zones (MZ) have been proposed to reduce sampling costs. The aim of this study was to evaluate the technical and economic impacts of replacing a dense systematic soil sampling design (cell size of 0.5 ha) by a systematic sampling with a smaller number of samples (cell size ranging from 1 to 4.5 ha), directed or conventional sampling design on the mapping of soil plant-available phosphorus (P), exchangeable potassium (K), and pHwater. The study was carried out in an agricultural area of 120 ha with soil classified as an Oxisol. The directed sampling designs were based on MZ delimited from data of elevation and overlapping of crop yield maps. Our finding revealed that systematic samplings with grids larger than 2 ha were not efficient to detect the spatial variability of soil P, K and pHwater. Larger systematic grid sizes, directed and conventional sampling design resulted in more generalist thematic maps, losing information about spatial variability of the soil attributes. Thus, from a technical point of view, soil sampling designs with a low density were little efficients, particularly for mapping P and K, due to their higher spatial variability. However, because soil P and K contents were close to or above critical levels and soil acidity was low (average pH close to 5.5), the different sampling designs presented little influence on fertilizer and liming recommendations. Therefore, we concluded that systematic soil sampling design may be replaced by soil sampling directed based on MZ or even by conventional sampling in soils with high fertility to reduce sampling costs. Nevertheless, crop responses must be monitored to validate fertilization management based on these simplifications on soil sampling procedure.