Maquinas e implementos para a colheita (parte 1)

Summary

This video lesson focuses on the intricacies of agricultural harvesting, particularly the machinery and implements used in crop collection. It delves into the importance of harvesting as the critical stage of crop production, where the success of prior steps like soil preparation and sowing is evaluated. The video covers different harvesting methods, from manual to mechanized, highlighting the role of machinery in increasing efficiency. The process of understanding physiological maturity and its importance for optimal harvest timing is discussed, with detailed insights into the mechanisms of cereal harvesters and their components, like cutting platforms and threshing systems.

Takeaways

• 😀 The harvest process is crucial in agriculture, as it determines the financial return and success of prior activities such as soil preparation and sowing.
• 😀 Harvesting can be done manually, semi-mechanized, or fully mechanized, with each method having its own advantages and disadvantages.
• 😀 The maturity of the crop plays a key role in deciding when to harvest, with physiological maturity being the point when the product is independent of the plant and no longer gains weight.
• 😀 For cereals like corn, the ideal harvesting moisture content is 18%, while for silage corn, the appropriate dry matter percentage ranges from 30% to 35%.
• 😀 For crops like beans, the ideal moisture content for harvest is 15% to 18%, and for coffee, a target is to have as many red cherries (serejo) as possible.
• 😀 Sugarcane harvest is based on planting time, typically 12 to 18 months after planting, while fruit harvest depends on quality and sugar content for optimal flavor and market value.
• 😀 Grain harvesters can be either tractor-pulled or self-propelled, with the core operation of cutting, threshing, and separating grain from husks being similar across both types.
• 😀 The cutting platform of a harvester uses a cutting mechanism (similar to a hair clipper) to slice the plants, with additional tools like a windmill helping to direct crops onto the platform.
• 😀 The harvested material is transported to the threshing system where the grain is separated from the husks and chaff through mechanical processes, such as a threshing cylinder.
• 😀 The cleaning system ensures that the harvested grain is free of impurities by using air currents to blow away smaller fragments of husks or straw before the grain is stored in the grain tank.

Q & A

What is the significance of harvesting in agricultural work?

Harvesting is considered the most critical part of agricultural work as it determines the success of all previous activities, such as soil preparation, sowing, and cultural management. It's the point where a farmer gets a financial return on the hard work done throughout the growing season.

What is the physiological maturity of a crop, and why is it important for harvesting?

Physiological maturity is the stage when a crop becomes independent of the plant, and its germination and vigor are optimal. At this point, the crop stops gaining dry matter, making it the ideal time to begin harvesting. This stage ensures the seed or product is fully developed and ready for collection.

How does the moisture content of crops affect the timing of harvest?

The moisture content in crops like maize, beans, and coffee helps determine the right time for harvesting. For instance, maize for grain is harvested when it reaches around 18% moisture content, while maize for silage is harvested at 30-35% dry matter content. Different crops require specific moisture levels to ensure optimal quality and yield.

What are the different types of harvesting methods discussed in the transcript?

The transcript discusses three types of harvesting methods: manual, semi-mechanized, and fully mechanized. Each method has its advantages and disadvantages, and the choice depends on factors such as crop type, scale, and the client's needs.

How do mechanized harvesters work, and what are their key components?

Mechanized harvesters consist of several components: a cutting platform to cut the crop, a feeding system (usually a conveyor or auger) to move the crop to the threshing system, a threshing mechanism to separate the grain from the chaff, and a cleaning system to remove impurities before storing the grain.

What role does the cutting platform play in the operation of a grain harvester?

The cutting platform is the first component of the harvester, where the crop is cut using a blade or cutter bar. In the case of crops like maize, the plant falls onto the platform after being cut. For crops like soybeans and beans, a 'molinete' or rotating mechanism is used to assist in cutting and feeding the crop onto the platform.

What is the function of the 'molinete' in a grain harvester?

The 'molinete' is a rotating mechanism used in harvesting machines to help cut crops like soybeans or beans. It assists by spinning and pushing the crop into the cutting platform, facilitating smoother harvesting.

How does the threshing system in a grain harvester work?

The threshing system uses a drum or cylinder that separates the grain from the stalk or husk. The material passes through the threshing drum, and the grain is separated from the rest of the plant matter. This is the critical step in converting the harvested crop into usable grain.

What are the differences between axial and radial threshing systems?

In an axial threshing system, the drum rotates in a way that the product moves in the same direction, allowing for longer contact with the cylinder, which increases efficiency. In a radial system, the drum spins in a perpendicular direction, which results in less contact time and generally lower performance.

How does the cleaning system in a harvester work?

The cleaning system uses air currents and sieves to separate any remaining impurities, such as chaff or small pieces of plant matter, from the grain. The clean grain is then directed into the grain tank, while the impurities are expelled out of the back of the machine.