Revista Engenharia na Agricultura - REVENG

Development of a low-cost iot platform for data collection

2021-10-26T09:04:09-03:00

Precision agriculture in the Internet of Things (IoT) integrates different technologies able to raise crop productivity, optimize resource efficiency, and accelerate decision making. However, the adoption of this technology is usually costly, affecting the acquisition by the farmers. Thus, the objective of this work was to develop and evaluate low-cost hardware to obtain data in a hydroponic system via IoT. The experiment was conducted at the Pici Campus of the Federal University of Ceará and split into three distinct stages. Firstly, the DS18B20 temperature sensors were calibrated in water, using the KR380 infrared thermometer as a comparison method. For the second step, when the hydroponic system was installed, the water temperature was monitored in the channel and not in the solution reservoir. In this same phase, the quality of data sending and receiving was investigated. In the third step, the sensory data were analyzed with those obtained by the local Meteorological Station. The calibration results revealed that the DS18B20 sensor has reasonable accuracy and excellent agreement and reliability between data. As for receiving and storing, only 6% of the total data was lost.

Analysis of pest incidence on apple trees validated by unsupervised machine learning algorithms

2021-09-15T15:14:19-03:00

Integrated pest control is a practice commonly used in apple orchards in southern Brazil. This type of management is an important tool to help improve quality and increase yields. This study aimed to identify areas with higher and lower incidence of aerial pests in a commercial apple orchard, regarding data collected from three different crops using georeferenced traps. Geostatistical analyses were performed, based on the modeling of semivariograms and spatial interpolation using the kriging method; and clustering, based on specific unsupervised machine learning algorithms for count data. The algorithms were selected from measures of stability, connectivity and homogeneity, seeking to identify areas with different incidence of pests that could help farmer decision making regarding insect population control using pesticides. The geostatistical analysis verified the presence of individual pest infestations in specific sites of the study area. Additionally, the analysis using machine learning allowed the identification of areas with incidence above the average for all analyzed pests, especially in the central area of the map. The process of evaluation described in this study can serve as an aid for risk analysis, promoting management benefits and reducing cost in the farms.

Evaluation of the quality and mechanical resistance of eggs with the application of biodegradable coatings

2021-12-08T21:15:23-03:00

The chicken egg is one of the most complete and balanced foods for human nutrition, representing an important source of animal protein of the highest quality. The application of coatings can extend the shelf life of these foods, minimizing the migration of moisture, gases (CO₂ and O₂), solutes and volatile aromatic compounds, and can even function as a vehicle for food additives. The objective of the present work was to test the effect of whey protein concentrate (WPC) based coatings with and without the addition of a lipid source (palm oil) on the quality and mechanical resistance of chicken eggs. The result of this study showed that the coating that offered the least loss of egg quality during storage was the WPC+oil coating. The presence of a lipid combined with a protein constituted a barrier to moisture and CO₂; consequently, this coating presented lower values for weight loss and pH, as well as higher values for Haugh unit and shell strength, characterizing better quality eggs.

Post-harvest of coffee: factors that influence the final quality of the beverage

2021-12-15T15:28:58-03:00

Brazil is the world’s largest producer and exporter of coffee and the second largest consumer market. Brazil offer differentiated and high quality products to maintain its leading position in coffee production and export. However, Brazilian coffee has suffered some limitations in its commercialization in the international market, due to qualitative aspects. The development of taste and aroma is highly complex, since hundreds of chemical reactions take place at the same time, such as the breakdown of proteins, polysaccharides, trigonelline and chlorogenic acid, mainly in the roasting process. Then, it is necessary that, in addition to pre-harvest management, there are post-harvest practices that meet consumer demands regarding the final quality of the beverage. Studies on physical and chemical changes in the composition of coffee beans must continue to be performed in a comprehensive manner, since factors such as damage to coffee beans, drying methods, processing, storage time, type of packaging and chemical components are directly related to sensorial properties and thus define the quality of the beverage at this point of view. Thus, the objective of this review was to relate the physicochemical, biochemical and physiological characteristics of coffee beans after harvest with the quality of the product after roasting.

Sugarcane wax extraction using hexane and limonene mixtures

2021-11-21T14:43:33-03:00

Hexane is the most widely solvent used in the lipids extraction process, as the case of the sugarcane wax. However, the use of this solvent is highly harmful to the environment and to human health. Limonene is a monoterpene found in the citrus peel, with great potential for use as a green solvent. In this study, the partial and total substitution of hexane by limonene was performed in the process of the sugarcane peel wax extraction to evaluate the effect of this substitution on the physicochemical characteristics of the wax. The extracted samples were compared with a commercial wax sample (carnauba) using the Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) and Infrared by Fourier Transform (FTIR) analyses. Through this study, we can conclude that the waxes obtained from the use of the hexane and limonene mixture solvents presented similar physicochemical characteristics to those found in commercial waxes. Thus, the total and/or partial substitution of the hexane by solvents less harmful to health and the environment, such as limonene, can be an alternative in the wax extraction process.

Model applicability to predict growth rates of insects throughout the storage of corn (Zea mays L.) grain

2021-12-08T21:16:26-03:00

Insect pest infestation in stored grains can cause several losses during storage, in addition to promoting the spread of fungi, changing the temperature of the grain mass, and reducing the value of the final product. Knowing the behavior of these insect pests and how they reproduce in the grain mass is essential to design more efficient control strategies and ensure a quality final product. Thus, this work aimed to accomplish modeling and simulation of the population growth of insects Rhyzopertha dominica, Sitophilus oryzae, Oryzaephilus surinamensis and Tribolium castaneum throughout the storage of corn grain, using data retrieved from digital sensors of temperature installed in three Brazilian storage facilities in different regions. Data were collected through managing system CERES (company Procer Automação e Sistemas) and retrieved from 1^st of July to 29^th September 2019. In each one of the facilities, a silo equipped with the aforementioned sensors was used. Mean weekly values of temperature of the grain mass and the intergranular relative humidity were used, calculated using the Modified Henderson equation. The silos evaluated in facilities 1, 2, and 3 have a static capacity of 2,100; 6,304, and 93 tones, respectively, considering soybean with a bulk density of 750 kg m-3. Higher growth rates of all assessed species were observed for the storage facility number 2; and lowest values for storage facility number 1. Storage facilities that presented a higher potential for the growth rate of insects are subjected to elevated levels of insect populations throughout time.

Photovoltaic generators: use by rural customers in Mato Grosso state

2021-10-27T15:29:48-03:00

In the current Brazilian energy scenario, the use of photovoltaic systems for generating energy is an excellent choice, as it combines electricity savings and energy production with less harmful impact on the environment. Mato Grosso is a state of great importance for agricultural production, in a country where agribusiness has a large share in the Gross Domestic Product (GDP). The aims of this study are to investigate the growing use of distributed photovoltaic system by rural customers in the state of Mato Grosso and compare it with the number of installations implemented in other consumer classes to eventually evaluate the participation in the state energy matrix and its applications. The analysis was carried out with data up to 2020 available from the registration system of the distributed generation of the National Electric Energy Agency (ANEEL) and the local electricity company Energisa Mato Grosso (EMT). The number of consumer units having photovoltaic generation systems in the state has grown on average 342% since 2015, when the first units were installed. When analyzing only rural facilities, this percentage rises to 347%. Although the participation of rural customers in the total number of installations is 7.04%, which are less significant than the other consumer classes, these systems are 6.44 times larger than residential systems, with a participation in the total state installed power of 21.74%.

Soil physical attributes and agronomic characteristics relationships of soybean in no-tillage

2021-12-17T10:17:40-03:00

The objective of this work was to evaluate the soil physical attributes and their relationship to soybean productivity under no-tillage system. The study was conducted in a Oxisol, based on randomized blocks design, with the treatments: no-tillage for 10 years (0 tractor traffic) and five tractor-traffic intensities (2, 4, 6, 8, and 12 passes), with five repetitions. An increase of macroporosity up to 10% under soil bulk density ranging from 1.51 to 1.56 mg.m^-3 and soil penetration resistance between 1.5 to 2.0 MPa, on the 0.00-0.10 m layer benefited the soybean productivity. The number of pods per plant, grain number per plant, stem diameter, and soybean productivity is higher in Oxisol, under intermediate compression. Soil bulk density and soil penetration resistance showed to be sensitive an indicators of soil physical quality, with more relation to soybean grain productivity.

Use of geotechnologies for morphometric analysis of experimental basin in the semiarid region to support hydrological simulation

2021-11-10T10:04:47-03:00

The morphometric characteristics help to regulate the hydrological processes of a basin. The understanding of these characteristics is essential for an adequate planning of water resources. The aim of this study was to analyze the sensitivity of the hydrological simulation to different pixel thresholds for the generation of the drainage network and to perform a detailed morphometric characterization of the sub-basin upstream of a fluviometric section (SBSF) installed in the experimental basin of the Jatobá stream, semiarid region of Pernambuco. The following thresholds were considered: 264, 132, 66, 55 and 44 pixels, corresponding to scenarios 1 to 5, respectively. The morphometric analyses were performed through hydrological modeling and the use of mathematical equations, where 25 morphometric indices were evaluated. The results indicated that scenarios 3, 4 and 5 adequately represented the hydrological processes. The physical parameters indicate that the basin has an elongated shape, with a low tendency for flood peaks under normal conditions of climatic events. Although the SBSF presents a low average slope, it was verified the existence of regions with high slopes, favoring the surface runoff, which requires the adoption of conservationist practices and the maintenance of native vegetation.