Revista Brasileira de Engenharia de Biossistemas

Gypsum-based composites reinforced with bamboo particles

Thu, 06 Jun 2024 00:00:00 +0000

This study aimed to evaluate the quality of gypsum-based mineral composites reinforced with bamboo particles. The particles size was 1.68 mm and 0.841 mm. The density adopted for the composites was 0.80 g/cm³. The following weight replacement ratios were adopted: 0; 2.5; 5.0; 7.5 and 10.0%. The water/solid mass factor of the composite remained constant. For each treatment two slabs of composites were produced. Physical and mechanical properties were determined: humidity, apparent density, water absorption (2 and 24 hours), modulus of rupture, modulus of elasticity and compression. The results showed that the apparent density and moisture content of the composites were not influenced by the insertion of the bamboo particles, while the water absorption was significantly reduced. The addition of the bamboo reinforcement particles did not cause improvements in the MOR and MOE properties, but all the MOR values of the treatments reached the value established by EN 13279-2 (EN, 2004). Although all treatments have reached the minimum values stipulated by the standard for compressive strength, all values were reduced with the insertion of bamboo particles. In general, the Dendrocalamus giganteus can be used as reinforcement in gypsum composites, however new parameters should be tested, such as: particle size; increasing the proportions of particles, pre-treatment of particles, addition of other additives, such as superplasticizer to water to improve workability and even use more than one reinforcement to obtain composites with improved properties.

Mapping and modeling of water erosion in the Revubué river Sub-Basin, Moatize, Mozambique

Geraldo Félix Pita Duarte — Sat, 21 Sep 2024 00:00:00 +0000

This study investigated water erosion in the Revubué River Sub-Basin, Moatize, Mozambique, utilizing advanced mapping and modeling techniques. Through detailed land use surveys and application of the Potential Erosion Model (EPM), we identified areas with moderate to severe erosion rates (φ = 0.54), particularly in zones of intensive agriculture (15% of the study area) and mining (1% of the study area). The results highlighted the influence of undulating topography (average slope of 9%) and intensive agricultural practices on erosion rates (0 – 25 ton/ha). Urgent implementation of soil conservation practices, such as contour plowing and terracing, was recommended to mitigate soil loss, improve agricultural productivity, and promote environmental sustainability. Agricultural sustainability was emphasized, focusing on investments in sustainable agricultural practices to preserve long-term soil health. Raising awareness among farmers about the impacts of soil erosion and implementing effective management practices were considered crucial. Extension services were recognized as key agents in disseminating knowledge for promoting eco-friendly agricultural practices.

Variability of drinking water for pigs and poutry the southern region of Brazil over a twelve – month period

Tue, 12 Nov 2024 00:00:00 +0000

The increase in global food demand has led to intensified production of pigs and poultry. In this context, water quality on farms needs to be monitored to ensure maximum production and animal welfare. This study aimed to evaluate the quality and variability of drinking water for animals over twelve months in properties in the Southern Region of Brazil. Physical, chemical, microbiological parameters, and the average rainfall index of nine water sources were observed. Variations in pH were noted among the evaluated water sources, as well as within the same source over monthly collections. A relationship between average rainfall and elevated iron levels was also demonstrated. Nitrate and nitrite levels exceeded Brazilian legislation at certain sampling points, posing risks to human and animal health. In 67.59% of samplings, total coliforms were present, and 59.26% showed the presence of Escherichia coli. The study highlighted the variability of water sources in the Southern Region of Brazil, reflecting the need for constant monitoring and treatment measures, such as water treatment stations, chlorination systems, and acidification in rural properties.

Genetic resistance and silicon in the control of stem rot in Capsicum spp.

Bruno Arcanjo Silva, Lorenna Leal Pires, José Evando Aguiar Beserra Jr — Wed, 05 Jun 2024 00:00:00 +0000

Pepper stem rot is a disease caused by Sclerotium delphinii, a necrotrophic pathogen and a natural soil inhabitant. Identifying genotypes of Capsicum resistant to the pathogen and applying silicon (Si) can be effective management measures. The objective of the study was to identify sources of resistance in 24 accessions of Capsicum spp. against S. delphinii, and to evaluate the potential of sodium silicate (Si) to induce resistance. Two experiments were conducted: In Experiment I, the resistance reaction of Capsicum in a greenhouse was evaluated. The experiment was conducted in two periods of the year (July and November 2019). In Experiment II, the effect of Si on Capsicum resistance was evaluated. The experimental design used in Experiment I employed randomized blocks in a factorial design of 2 (isolates) x 24 (accessions), with five replications. For Experiment II, six accessions were selected with contrasting resistance responses observed in Experiment I, in a factorial design of 1 (isolate) x 6 (accessions) x 4 (doses: 0.0, 0.025, 0.05, and 0.1 mL per vase). Accessions BGH 71 and BAGC 134 showed greater resistance to the pathogen. Accession BAGC 134 demonstrated high resistance stability in both periods and against the two isolates tested. Si doses had no significant effect on the resistance reaction. Therefore, the genotypes BGH 71 and BAGC 134 have the potential to be used in breeding programs for Capsicum for resistance to S. delphinii for control of stem rot.

Parsley production using organic sources of phosphorus

Thu, 04 Apr 2024 00:00:00 +0000

Parsley is a condiment produced mainly by small producers, often in the organic system. Organic fertilizers make nutrients slowly available to plants when compared to inorganic fertilizers, an important quality for phosphorus (P), which is a nutrient that tends to fixate and adsorption. Thus, the objective of this work was to evaluate the production of parsley with the use of organic sources of phosphorus in different proportions. Fourteen treatments were evaluated, resulting from the factorial 6 x 2 + 2: six proportions of two phosphate fertilizers (thermophosphate Yoorin^® (TY) and bone meal (BM)), two doses (recommended (180 kg.ha^-1 of P₂O₅, and double this) + two controls (without phosphate fertilizer; and with inorganic triple superphosphate fertilizer (recommended dose)). The proportions were: 100% P with TY; 80% P with TY + 20% with BM; 60% P with TY + 40% with BM; 40% P with TY + 60% with BM; 20% P with TY + 80% with BM; 100% P with BM. Shoot height, number of leaves, fresh and dry weight of leaves in two harvests and the total of these two harvests were evaluated. No significant differences were obtained in the two harvests. The lack of effect to phosphate fertilization may be related to the high initial P content in the soil (123 mg.dm^-3), which shows that in this case, fertilization with this nutrient is not necessary to produce parsley, despite the official recommendation to fertilize with phosphorus in a soil with a high P content.

Evaluating the suitability of Brazilian native species for riverbank stabilization and protection

Paula Letícia Wolff Kettenhuber, Fabrício Jaques Sutili — Mon, 07 Oct 2024 00:00:00 +0000

In Brazil, soil and water bioengineering techniques have mainly been used for hydraulic stabilization, water course management and to re-establish the vegetation in fluvial environments. In these techniques plants are considered as an important structural component and their use requires adequate selection. The present study aimed to evaluate the root system and shoot development traits of the Allamanda cathartica L., Ludwigia elegans (Camb.) H. Hara and Sesbania virgata (Cav.) Pers species. The experiment was conducted in a greenhouse at the Laboratory of Soil Bioengineering at the Federal University of Santa Maria. The following variables were evaluated after 120 days: the survival rate, average height, average root collar diameter, average number and sum of shoot length per plant, average number of primary roots and the sum of primary root length, length of the largest root and root dry mass per plant. The percentage of fine roots and coarse roots and distribution of root dry mass percentage in soil depth were also evaluated. The results confirm the suitability of the L. elegans, S. virgata and A. cathartica species for riverbank stabilization and protection in soil and water bioengineering works.

Do low-cost digital tools allow measuring the cladode area?

Tue, 03 Dec 2024 00:00:00 +0000

This study evaluated low-cost digital tools for estimating cladode area by mobile and fixed devices. We conducted the experiment at the Serra Talhada Academic Unit of the Federal Rural University of Pernambuco with pear cactus (Nopalea cochenillifera Salm-Dyck and Opuntia stricta (Haw.)). In this sense, we used four software to measure the cladode area: LAFore (fixed device), ImageJ (fixed device), Easy Leaf App (mobile device), and Petiole App (mobile device). We considered the LAFore software as a reference and used the following statistical parameters: linear regression, correlation coefficient (r), Willmott index (d), confidence index (c), and standard error of estimate (SEE). The software on fixed devices (ImageJ and LAFore) showed similar results, with performance considered excellent, and the Easy Leaf App showed a very good performance among mobile devices.

Bean yield estimation using unmanned aerial vehicle imagery

Diane Gomes Campos, Rodrigo Nogueira Martins — Thu, 06 Jun 2024 00:00:00 +0000

The common bean is a crop of substantial socioeconomic importance that is cultivated throughout the Brazilian territory. Despite that, studies conducted so far have shown limitations in the methodologies used for yield estimation. In this sense, emerging technologies such as unmanned aerial vehicles (UAVs) can help both in crop monitoring and in assessing crop yield. Therefore, this study aimed: (1) to estimate the bean yield using spectral variables derived from UAV imagery and (2) to define the best vegetative stage for yield estimation. For this, data from a field experiment were used. The beans were planted in a conventional system in an area of 600 m² (20 x 30 m). During the crop cycle, six flights were carried out using a UAV equipped with a five-band multispectral camera (Red, Green, Blue, Red Edge, and Near-infrared). After that, 10 spectral variables composed of the bands and five vegetation indices (VIs) were obtained. At the end of the season, the area was harvested, and the yield (kg ha^-1) was determined. Then, the data was submitted to correlation (r), and regression analysis. Overall, all developed models showed moderate performance, but in accordance with the literature, with R² and RMSE values ranging from 0.52 to 0.57 and from 252.79 to 208.84 kg ha^-1, respectively. Regarding the best vegetative stage for yield estimation, the selected models used data from the second flight (52 days after planting) at the beginning of pod formation and filling (between stages R7 and R8).

Soil compaction in progressive agricultural tractor treads

Wed, 05 Jun 2024 00:00:00 +0000

Soil compaction is one of the main problems in world agriculture. It is known that, even in soil conservation management, such as in no-till, the transit of agricultural machinery damages the soil structure, therefore, it is essential to better understand the compaction processes and ways to alleviate the problem. In soils that have traditional tillage management, just one machine pass can damage the physical structure. This research aimed to evaluate the levels of compaction as a function of different passages of an agricultural tractor, considering the hypothesis that, during agricultural operations, a machine transits several times through the same place in the crop. The experiment was carried out on plowed and harrowed agricultural soil in the state of São Paulo. Resistance to soil penetration at different depths was evaluated, and the averages were correlated as a function of the number of steps taken by the tractor. Results showed that approximately 60% of the total soil compaction occurs in the first passes of the agricultural tractor, and above five passes the increase in compaction is minimal. At depths of 20 to 30 cm, the largest RSPs were found. It is concluded that a good planning of machinery traffic is essential, because in the case of a motor-mechanized set moving out of its predestined route, the soil structure is permanently affected.

Cotton responses to potassium fertilization in Northeastern Brazil

Thu, 06 Jun 2024 00:00:00 +0000

Carrying out research evaluating the responses of cotton plants to potassium fertilization in different regions is of great importance, as it allows the development of recommendations for fertilization of this nutrient for the crop based on results from localized studies. Therefore, the aim of this work was to evaluate the responses of cotton plants to potassium fertilization in the climate and soil conditions of the Cariri region, located in the northeastern State of Ceará, Brazil. The experiment was conducted in an experimental area at the School of Technology (FATEC - Cariri campus), located in the city of Juazeiro do Norte, Ceará State. A completely randomized design (CRD) was adopted for statistics. The treatments were composed of a combination of five doses of potassium (0, 25, 50, 75, and 100 kg ha^-1 of K₂O, equivalent to 0, 50, 100, 150, and 200% of the K recommended for cotton cultivation) with four replications. At 70 days after sowing, the plants were collected. Measurements were taken of stem diameter, number of leaves, root dry matter, shoot dry matter, total dry matter, number of floral buds, number of cotton balls, and cotton ball weight. Except for the shoot dry matter and the cotton ball weight, the remaining analysed variables were significantly influenced by potassium doses. Potassium doses between 65 and 100 kg ha^-1 of K₂O maximized the growth, dry matter, and production components of the cotton plant in the soil and climate conditions of the Cariri region, northeastern Brazil.

Modeling the evaluation of methods for determining the basic density of wood in forest species based on data from a neuro-fuzzy inference system

Tue, 17 Dec 2024 00:00:00 +0000

The forestry sector is one of the agribusiness sectors that generates the most wealth for the national economy, as it brings benefits to society, from the wood itself for industries, biomass for energy production, and to the environment, reducing pressure on native forests and the reuse of land degraded by agriculture. In view of this, this study was carried out to predict the different basic densities in tree species under the influence of two factors, nine different tree species in relation to three different density methodologies using the Neuro-Fuzzy System. Tree basic density modeling was carried out using effective species parameters and different calculation methodologies adapted to the Neuro-Fuzzy Inference System (ANFIS). In the ANFIS model, 67% and 33% of the total data were considered as training and test data, respectively. The numbers of pertinence functions were selected 9 for species and 3 for methodologies for the input data. ANFIS training was carried out using the hybrid method. The average R2 determination coefficients were 87.32% and 97.42% for the field and ANFIS models, respectively. The model obtained using ANFIS showed a high accuracy of 4.36%. Compared to the field data, the ANFIS model was highly accurate and can be used to estimate the basic density of the trees in this study.

Treatment of cauliflower seeds with product based on bacillus subtilis aiming plant seedling production, development and productivity.

Tue, 24 Sep 2024 00:00:00 +0000

The relation between seed vigor and field performance is not yet fully understood, and it is questionable whether these effects extend to more advanced phenological stages and if they affect crop production. In front of that, the objective of this study was to evaluate the effects on the seedlings and plant production of cauliflower using doses of product based on Bacillus subtilis in seed treatment. The study was conducted in Ilha Solteira city, São Paulo State. The experimental design was a complete randomized design for laboratory analysis and complete randomized blocks for the field stage. Ten treatments were studied in a 2 x 5 factorial scheme with four replications. The treatments consisted of seed treatment of cultivars Sharon and Barcelona with Bacillus subtilis-based product (strain FMT001 containing 3x10⁸ cells cm^-3) in five doses (0, 100, 200, 300 and 400 mL per 10 kg of seeds). Seed vigor and crop yield (shoot, root and inflorescence weight, leaf number, inflorescence diameter and yield) characteristics were evaluated. Cultivars averages were compared by Tukey test (p <0.05) and regression for the doses. The results showed that doses of 200 and 400 mL per 10 kg of seeds increased the percentage of strong seedlings of cultivars Barcelona and Sharon, respectively.

Artificial intelligence applied to estimate soybean yield

Thu, 14 Mar 2024 00:00:00 +0000

The application of mathematical models using biotic and abiotic factors for the efficient use of fertilizers to obtain maximum economic productivity can be an important tool to minimize the cost of soybean (Glycine max (L.) Merr.) grain yield. In this sense, using Artificial Neural Networks (ANN) is an important tool in studies involving optimization. This study aimed to estimate soybean yield in Luiziana, Paraná state, Brazil, by considering two growing seasons and an Artificial Neural Network (ANN) as a function of the morphological and nutritional parameters of the plants. Results reveal a well-trained network, with a margin of error of approximately 10^-5, thus acting as a tool to estimate soybean data. For the phases, model validation and network test, i.e., data that were not part of the training (validation), the errors averaged 10^-3. These results indicate that our approach is adequate for optimizing soybean yield estimates in the area studied.