Alberto Carvalho Filho

Perdas na colheita mecanizada de soja no estado de Minas Gerais

This work aimed the evaluation of soybean mechanical harvesting in Minas Gerais State, during 2002/2003 soybean crop, comparing grain losses according to harvester age, harvesting ground speed, track system (axial and radial) and property condition (proper or rented). Ground speed and tracking cylinder rotation were also studied except when they were evaluated as variable function. The results indicate that the harvesters up to five years old, independent of their rate of annual use, had lesser losses than the harvesters with more than six years. The proper harvesters had presented minors losses when comparing with rented and the machines with axial track system presented minors losses than those with radial track system.

SEMEADORA-ADUBADORA: EXIGÊNCIAS EM FUNÇÃO DO PREPARO DO SOLO, DA PRESSÃO DE INFLAÇÃO DO PNEU E DA VELOCIDADE

Planter machines, responsible for the correct placing of seeds and fertilizer in the ground, have dosing mechanisms set in motion by the drive wheels, as they rotate in function of the contact with the ground surface. This contact is influenced, among other factors, by tire pressure. The objective of this work was to study the performance of a planter as affected by soil tillage, machine speed and planter tire pressure. The following variables were evaluated: traction force and drawbar pull, fuel consumption, field capacity, wheel skidding, initial stand and longitudinal seed distribution. The greatest force was needed in the no-tillage system, which also demanded the highest power and hourly fuel consumption. The same results were found at the fastest speed. In this system the tire pressure of the planter wheels reduced skidding, improved the initial plant stand.

Efeito da profundidade de semeadura e de rodas compactadoras submetidas a cargas verticais na temperatura e no teor de água do solo durante a germinação de sementes de milho

As rodas compactadoras das semadoras-adubadoras tem como principal funcao, propiciar o bom contato entre o solo e a semente para garantir a germinacao das sementes e a emergencia das plântulas. Objetivou-se, neste trabalho, estudar a influencia de tres modelos de rodas compactadoras, tres profundidades de semeadura e tres niveis de carga sobre a roda compactadora sob a temperatura e o teor de agua do solo. O trabalho foi desenvolvido na pista de ensaios de semeadura, localiza em Uberaba, MG, em Latossolo Vermelho distrofico, utilizando-se o delineamento experimental de parcelas sub-subdivididas, com 27 tratamentos e quatro repeticoes. As rodas com maior area de contato com o solo proporcionaram maiores valores do teor medio de agua e da temperatura do solo. O nivel de carga sobre a roda compactadora nao afetou a temperatura e o teor de agua do solo.

Métodos de preparo do solo: alterações na rugosidade do solo

Trying to relate the soil tillage methods with some of their effects in Haplustox, it was installed in the municipal district of Uberaba/MG, a research using a completely randomized experimental design in factorial array with five treatments and four replications. The treatments were composed by the soil tillage: chisel plow, rotary tiller, moldboard plow, disk harrow and disk plow. They were appraised: soil mobilized area, elevation area, medium thickness of the mobilized layer, roughness index and the alteration of the roughness of the soil. It was verified that the chisel plow provided larger roughness index of the soil being framed in the conservationist method disaggregating less the soil, collaborating with the smallest soil losses for erosion.

Efeito de rodas compactadoras submetidas a cargas verticais em profundidades de semeadura sobre o desenvolvimento do milho

The success of the establishment of a crop depend on several factors and the seeders press wheels should be capable to improve the contact soil-seed in order to promote good seed germination. The present work had as objective to study the influence of three models of press wheel, three depths of sowing and three load levels on the press wheel on the germination and development of the corn grow, in a projected sowing assay lane for this purpose. The experiment was carried out at municipal district of Uberaba - MG, Brazil, in a split plot array, with 27 treatments and four replications, used to evaluate agronomic characteristics of the corn crop. The results evidenced that the depth of sowing was the factor that more affected the vegetative development of the corn crop in the stadium 2, and none of the evaluated characteristics in the stadium 4 had significant differences in the measures of the corn development.

Comportamento da cultura do sorgo em função do tipo de rodas compactadoras e cargas verticais impostas na operação de semeadura

Sorghum can be cultivated in areas and environmental situations droughts and hot, which other cereals productivity is uneconomical. When sorghum sowing is accomplished in an efficient way benefits can be verified in productivity. The objective of this work was to evaluate the behavior of sorghum sowed under three levels of vertical load imposed on the press wheels of the seeder. The experiment was carried out in FAZU - Faculdades Associadas de Uberaba (MG), Brazil, with plots arranged in randomized complete block design in split-plot, with three models of press wheels and three vertical loads with five repetitions. It was observed that there were not effect of the press wheels and loads treatments in relation to the days for emergency, but the lineal regression showed significant for vertical load. The height, the medium moisture of the plants and the production of green and dry matter of the sorghum did not differ among the treatments.

Avaliação da influência de cargas verticais sobre diferentes rodas compactadoras no ciclo de semeadura do milho

Assim como outras culturas de origem tropical, o milho exige durante o seu ciclo vegetativo, calor e umidade para se desenvolver, e as condicoes de instalacao da cultura podem definir uma boa ou ma producao. O objetivo deste trabalho foi avaliar a influencia de cargas verticais sobre rodas compactadoras no ciclo da cultura do milho. Este trabalho foi conduzido nas Faculdades Associadas de Uberaba - FAZU, no municipio de Uberaba (MG), e instalado no delineamento em blocos ao acaso com tres modelos de rodas compactadoras e tres cargas verticais com duas repeticoes, na Pista de Ensaios de Semeadura, constituida de canais de solo. Observou-se que o numero de dias para emergencia, altura de plantas, numero de folhas e a producao nao foram afetados significativamente para os tratamentos estudados.

SISTEMAS DE CULTIVO EM MILHO (Zea mays L.) E SEUS EFEITOS RESIDUAIS NOS TEORES DE NUTRIENTES NO SOLO E NA PLANTA

O presente trabalho objetiva avaliar o efeito residual no 7o e 8o ano de quatro sistemas de cultivo, mantidos sob plantio direto, comparados ao sistema de cultivo convencional. O experimento foi desenvolvido nos anos 96/97 e 97/98 em um latossolo vermelho escuro, textura media, na Fazenda Experimental da Faculdade de Ciencias Agrarias e Veterinarias – Universidade Estadual Paulista em Jaboticabal – SP. As caracteristicas agronomicas: indice de area foliar, altura de plantas, massa verde, massa seca, desenvolvimento radicular, massa verde na epoca da ensilagem, producao de graos e peso de 100 graos, foram avaliados nos tratamentos, encontrando diferencas significativas para todas as caracteristicas, exceto producao de graos e area foliar. Neste trabalho, conclui-se que os sistemas de cultivo em milho afetaram significativamente as caracteristicas agronomicas do milho.