Vilnei de Oliveira Dias

Distribuição de sementes de milho e soja em função da velocidade e densidade de semeadura

With the objective to evaluate the distribution of corn and soybean seeds by a precision seeder in function of the displacement speed and seeds density, an experiment was made in track of sand according to international standard. The treatments consisted of the combination among four speeds, three sowing densities for the corn and four for the soybean, being appraised the transversal distribution, longitudinal distribution and final seeds density. It was observed that the elevations of the displacement speed from 3.5 to 7.0km h-1 for the corn and from 4.3 to 11.0km h-1 for the soybean did not reduce significantly the final densities of sowing. The increase in the sowing density from 3 to 7 seeds m-1 for the corn and from 8 to 20 for the soybean reduced the percentile of acceptable spacings for both the cultures, independent of the displacement speed.

Utilização de um veículo aéreo não-tripulado em atividades de imageamento georeferenciado

The aim of this study consisted in developing and testing an alternative procedure for data acquisition, telemetry, monitoring and geo-referencing in agricultural fields. The proposed approach was implemented by placing dedicated electronic gear onboard Unmanned Aerial Vehicles (UAV). For this purpose an UAV was assembled at the Federal University in Santa Maria, Brazil and equipped with the required hardware for image and control points acquisition. Tests have shown that the proposed approach can be regarded as a valuable tool to detect areas affected by faulty germination, weed infestation and mapping in general. The tests have also shown that poor quality of the acquired image data was the main drawback in the equipment onboard the UAV, pointing to the need to reevaluate the system with regard to this particular aspect.

Corn gatherer platform investment analysis in reduced spacing: oscillation effect in the productivity, corn and seed price

O objetivo deste trabalho foi avaliar a viabilidade economica do investimento em plataformas colhedoras de milho em espacamento reduzido quanto a aumentos percentuais de produtividade, do preco do milho e da semente. Para tal, foi confeccionado fluxo de caixa diferencial e, a partir desse, determinaram-se a Taxa Interna de Retorno (TIR) e a Razao Beneficio/Custo (B/C) do investimento para as combinacoes de aumentos de produtividade em diferentes niveis tecnologicos. Fez-se analise de sensibilidade para variacoes no preco pago pelo produto e nas despesas com sementes para o indicador Valor Presente Liquido (VPL). Foram consideradas areas de 100 a 300 ha e produtividades de 70; 100; 130 e 160 sc ha-1. Concluiu-se que os acrescimos de produtividade afetam positivamente a TIR e a razao B/C. Quando esses acrescimos sao superiores a 7,5%, o investimento e viavel economicamente na maioria das situacoes analisadas. Variacoes no preco de sementes tem baixo efeito sobre o investimento, e oscilacoes no preco do milho sao toleradas na maioria das situacoes testadas.

Tamanho amostral para ensaios de mecanismos dosadores de sementes de milho em esteira carpetada

Because to the diversity of sample sizes used in performance evaluations of seed metering mechanisms, the objective of this study was to determine the sample size for laboratory experiments with horizontal plate and pneumatic seed meters, and treatment effects in the corn seed distribution. For this, experiment was conducted under laboratory conditions, according to the international standard ISO 7256/1. The treatments comprised a combination of four metering mechanisms (two pneumatic and two horizontal plate) with three sowing speeds, 0.7, 1.4 and 2.1 m s-1. Methods were used for determining the sample size, sampling intensity and adapted bootstrap. Regarding the distribution of seeds, the meter mechanisms studied show no differences in the regularity of distribution, quality dropped with increasing speed. Referring to the sample size, can be reduced to 103 seed spacing with error level of 5% of the sample mean for the corn, independent of seeding speed and metering system used.

DESEMPENHO DE UMA SEMEADORA NO ESTABELECIMENTO DO TRIGO EM FUNÇÃO DA VELOCIDADE DE SEMEADURA

A study was accomplished in Vacaria (city placed in Rio Grande do Sul state, in Brazil), aiming to rate a seeder-fertilizer machine’s performance in three speeds of displacement over wheat sowing. Evalutions were carried out in compacted soil lane and directly in the field, with the seeder-tractor set operating in ryegrass’ straw, evaluting up seeds and fertilizer cross distribution, longitudinal distribution of seeds, depth of seeds deposition and transversal profile area, called up by the groover machanism. There was an increase in the of frequency range classes number with the lifting of displacement speed from 9.8 to 12.6 km h-1. The perpetual screw fertilizer doser mechanism presented variations in the distribution of fertilizers. There was lifting the planting density and transversal soil profile mobilized with increasing speed of displacement. It was concluded that the seeder shows a good performance to wheat sowing when agronomic culture recomendations were considered.

Levantamento e identificação dos símbolos gráficos utilizados para a caracterização de controles e comandos em máquinas agrícolas

The graphic symbols that indicate the function of the commands and controls of the agricultural machines, keep its safer operation. Therefore, this work had as objective, the identification of the existent ones in the available agricultural machines in the four principal concessionary of Santa Maria City - RS, Brazil, the rising were used as parameter, the graphic symbols recommended in the standards, and the existent ones in the studied machines were photographed and later logged in a spreadsheet. The conformities and nonconformities found were contained in a table for better visualization. The result found was average of 86%, in relation to the use of the graphic symbols recommended by the standards, however, there is the use of graphic symbols also created by the own company, what generates doubts in the operator of the agricultural machine, because not always the meaning of the same ones coincides with described in the standards. The results demonstrated that the fabricator of agricultural machines studied use the existent standards, fact this that leads the equality lack among the market placed products.