Dauto Pivetta Carpes

Demanda energética e mobilização do solo com o uso de escarificadores em sistemas de semeadura direta

Reduction in sowing period and intensification of production in no-tillage system, promoted an increase in the frequency of the use of machines and implements, causing compaction of soil due to traffic. The compaction, in addition to affecting the development of plant roots, increases the power demand of the implements, justifying the use of chisel plows for soil decompactation. The performance of two chisel plows (Shank + tip), one commercial and one experimental, was evaluated to understand the chiseling (scarification) operation adapted to no-tillage system and compare two chisel plows, using as parameters such as energy and soil variables. The experimental decompactation element performed better in comparison to commercial, in key variables, such as fuel consumption, power and traction force. When installed ahead of descompactation elements the cutting disc did not alter the traction force and reduced the fuel consumption and power. The increase in the speed provided an increase in traction force, power and fuel consumption.

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.