Gastão Moraes da Silveira

Determinação da eficiência de campo de conjuntos de máquinas convencionais de preparo do solo, semeadura e cultivo

The profitability of any farm or of a certain crop depends on the adequate management of the tasks executed. For that, in mechanized farms, the careful controlling of agricultural machine and implements, always, deserved a great attention. In this paper, an automatic system of data acquisition, designed for field information survey, was used. The obtained data are related with time and motion, work capacity and field efficiency. The system was conceived for determining the position of the tractor in the field by means of global positioning system (GPS), the fuel comsuption and forward tractor velocity. This set of data makes the control of the operational parameters possible, generating reports containing the most important management indicators such as operational yield and the work conditions. Machinery productivity measurements were carried out in corn fields of the Automation and Agricultural Engineering Center of IAC/SAA. Conventional plowing, harrowing, seeding and mechanical weed control operations were monitored, aiming to characterize performance characterization of the machinery used.

Métodos mecânicos e químico no controle de ervas daninhas em cafezal

Mechanical (disc harrow, rotary cultivator, off-set rotary shredder), chemical (herbicide) and hand hoe weeding are compared in a coffee crop grown on a latosol. After ten years there was no significant yield difference among the treatments. There was however, visible signs of erosion due to the use of disc-harrow, rotary cultivator, and herbicide.

ESTUDO DO CONSUMO DE ENERGIA POR ÓRGÃOS ATIVOS DE ROÇADORA

Brazil, a country that has over 40 million hectares with pasture of brachiaria (Brachiaria sp.), is the second largest bovine breeder in the world. For the maintenance of this pasture, the most important item to be developed is its cleanness. In this context the goal of the present report was to study the active parts of a rotor mower, evaluating the types of actuating forces in the machine: new sharpened blade with deflector, new sharpened blade without a deflector, new blade not sharpened without deflector, used blade not sharpened with deflector, used blade not sharpened without a deflector, and chains with and without deflectors, replacing the blades. The experiment was outlined in randomized complete blocks with eight treatments and six replicates. The treatments were not statistically different in relation to the analyzed values: performance and energetic use.

Sistemas de preparo do solo para as culturas de soja e trigo

In a field experiment set up in Assis county, State of Sao Paulo, Brazil, two seeding processes namely no-till and conventional tillage systems for soybean (Glycine max (L.) Merrill) and wheat (Triticum aestivum L.) (double cropping) were studied. Special emphasis was given to the different seeding machines. Three crop yields were obtained. For wheat the treatments were: conventional seeding (heavy disking and leveling disking) and no-till. For soybean we had: conventional seeding plus chiseling; conventional seeding; plowing and disking; plowing and disking plus scarifying and no-till. The results showed that the interaction among the treatments were not significant, and that the soil management for soybean did not affect the wheat production. Fuel saving was significant for both crops in the no-till system. Machine articulation was essential to fit the roughness of soil surface in no-till.

Uso alternado de métodos mecânicos e químicos de controle de ervas daninhas em cafezal

The use of several methods of weed control (disc-harrow, rotary cultivator, off-set rotary shredder and herbicide) was studied and compared with hand cultivation. The treatments were made alternatively, trying to prevent the inconveniences observed when certain machines were sistematically used. After five years of observations, no significant statistical difference was noticed among several combinations: a) off-set rotary shredder versus herbicide; b) off-set rotary shredder versus rotary cultivator; c) off-set rotary shredder versus disc harrow; d) off-set rotary shredder (in the rain season) versus herbicide (in the dry season).

Mounted implement dynamometry: a simplified solution

An intermediary tower-articulated arm device, for attachment to three-point hitch of mounted implements, with ground whells, more specifically, multiple row seed-planters, was developed and tested on draft determination works. A single ring with electrical extensometers connected in full bridge, was used for sense traction compression efforts, anchored by flexible steel cables between the implement bar and the base of the intermediary tower. Designed for works on tie range of 0-6,000N, submitted to static calibration tests, showed high linearity, with R = 0.9997, an excellent zero return and a resolution of around 70N. A seven row seed-planter was then tested in two sites, firm ground, plane and inclined, and plane, prepared for planting. Draft values from the two first conditions were highly consistent with results obtained from simple theoretical calculus. This, allied to its simplicity of conception, confers to tire device a great deal of reliability. Its use alters the tractor-implement geometry, not being a major problem if there is interest on draft efforts only, for these kind of implements. Results from works in the site prepared for planting, so different from literature citations, say about of convenience of sistematic work for the knowledge of real draft requirements of mounted implements in our conditions.

Three soil management systems in corn crop: a comparative study in State of São Paulo, Brazil

Three crop production systems (namely conventional, reduced tillage and no-till) were compared as to yields, fuel consumption, and number of machine hours per hectare in a five-year experiment (1979/80 to 1982/83) carried out at the Experiment Station in Jundiai, State of Sao Paulo, Brazil. No significant differences among treatments were detected in the yields, althought they came up in fuel consumption and number of machine hours. The performance of a disc cultivator was also evaluated. The no-till system showed the least values for fuel consumption and number of machine hours, while the reduced tillage showed intermediate results and the conventional system the highest values. The disc cultivator in the no-till system demonstrated the possibility of eliminating the use of herbicides in the inter-row cultivation. Once the three systems showed significant differences in fuel consumption and number of machine hours per hectare but not in the yields, both factors could be taken in consideration in the adoption of one of the systems evaluated.Tres sistemas de manejo do solo em cultura do milho (cultivo convencional, cultivo reduzido e plantio direto) foram comparados do ponto de vista de consumo de combustivel e rendimento operacional, mediante a analise de resultados de experimentos realizados em campo de producao da Estacao Experimental de Jundiai, com duracao de cinco anos (de 1978/79 a 1982/83). A produtividade, tambem objeto de analise, foi tomada como fator condicionante. Nao foram constatadas diferencas significativas entre os tres sistemas quanto a produtividade, tendo, porem, os mesmos diferido entre si quanto ao consumo de combustivel e rendimento operacional. O sistema que apresentou menor consumo e exigiu o menor numero de horas de trabalho por hectare foi o plantio direto, seguido pelos cultivos reduzido e convencional. O desempenho satisfatorio de um cultivador de discos inicialmente desenvolvido para o plantio direto tomou desnecessario o uso de herbicidas na fase de pos-plantio, pratica normalmente empregada no plantio direto. O fato de os sistemas de manejo terem diferido entre si quanto ao consumo de combustivel e rendimento operacional indica que esses fois fatores podem ser considerados numa analise mais ampla para a escolha de um deles.

Comparação entre três sistemas de manejo do solo em cultura de milho

Three crop production systems (namely conventional, reduced tillage and no-till) were compared as to yields, fuel consumption, and number of machine hours per hectare in a five-year experiment (1979/80 to 1982/83) carried out at the Experiment Station in Jundiai, State of Sao Paulo, Brazil. No significant differences among treatments were detected in the yields, althought they came up in fuel consumption and number of machine hours. The performance of a disc cultivator was also evaluated. The no-till system showed the least values for fuel consumption and number of machine hours, while the reduced tillage showed intermediate results and the conventional system the highest values. The disc cultivator in the no-till system demonstrated the possibility of eliminating the use of herbicides in the inter-row cultivation. Once the three systems showed significant differences in fuel consumption and number of machine hours per hectare but not in the yields, both factors could be taken in consideration in the adoption of one of the systems evaluated.Tres sistemas de manejo do solo em cultura do milho (cultivo convencional, cultivo reduzido e plantio direto) foram comparados do ponto de vista de consumo de combustivel e rendimento operacional, mediante a analise de resultados de experimentos realizados em campo de producao da Estacao Experimental de Jundiai, com duracao de cinco anos (de 1978/79 a 1982/83). A produtividade, tambem objeto de analise, foi tomada como fator condicionante. Nao foram constatadas diferencas significativas entre os tres sistemas quanto a produtividade, tendo, porem, os mesmos diferido entre si quanto ao consumo de combustivel e rendimento operacional. O sistema que apresentou menor consumo e exigiu o menor numero de horas de trabalho por hectare foi o plantio direto, seguido pelos cultivos reduzido e convencional. O desempenho satisfatorio de um cultivador de discos inicialmente desenvolvido para o plantio direto tomou desnecessario o uso de herbicidas na fase de pos-plantio, pratica normalmente empregada no plantio direto. O fato de os sistemas de manejo terem diferido entre si quanto ao consumo de combustivel e rendimento operacional indica que esses fois fatores podem ser considerados numa analise mais ampla para a escolha de um deles.

Eficiência de diversos equipamentos para incorporação ao solo do herbicida trifluralin

This research investigates the efficiency of trifluralin incorporation in soils using four different equipments, such as, disk harrow, rotary plow, flexible spiketooth harrow and rotary hoe, during 1978/1979 and 1979/1980, at Campinas, State of Sao Paulo, Brazil, in cotton fields. Laboratory tests were also carried out to verify the depth of the herbicide action using soil samples collected through special cylinders with known diameter and height and sowing seeds of check plants. Rotary plow showed the best results. In regarding to the disk harrow, normally used to incorporate trifluralin, double harrowing at different depths is suggested as a good practice, superposing up to half harrowing width in the second pass.