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Method
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Description
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Advantages
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Disadvantages
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1. Manual reaping and threshing
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- Cutting, stacking, bundling, handling and piling by hand
- Threshing by beating
- Cleaning by winnowing
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- Efficient
- Most effective in lodged crop
- Winnowing/cleaning necessary
- Less weather dependent
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- High labor cost· Skill dependent
- Susceptible to grain damage
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2. Manual reaping and threshing by machine
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- Cutting and stacking by hand
- Threshing by machine
- Cleaning by machine or by hand
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- More effective in wet season harvest-wet crop conditions
- Higher capacity than manual
- Lower labor requirements
- Less dependent on field size
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- Higher capital cost
- Dependency on the availability of contractor
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3. Reaping and threshing by machine
4. Stripper harvesting and threshing by machine
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- Reaping by machine
- Threshing by machine
- Cleaning by machine or hand
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- Higher capacity than manual
- Lower labor requirements
- Less dependent on field size
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- Higher capital cost
- Dependency on the availability of contractor
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5. Combine harvesting
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Standard Combine-harvester
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- Harvesting, threshing, and crop cleaning are done mechanically
- Cutter-bar cuts crop, while conveying system feeds crop into the threshing and cleaning systems
- Threshing drum tip speed ranges from 20 to 25 m/s
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- High throughput; timeliness
- Produces Clean grain
- Spread straw back in the field
- Multi-crop ability (often used for wheat)
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- Higher Cost
- More straw left behind in the field
- Less effective in partially lodged crop
- Can not be used for Basmati rice
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Combine-harvester with stripper-header
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- Same as above except a stripper header is used instead of a cutterbar
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- Highest throughput
- Less power required for subsequent threshing and cleaning operations
- Can start threshing earlier in the day
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- High Cost
- Not suited for small, muddy Asian fields
- Problems in lodged crop
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Head-Feed Combine
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- Cutterbar cuts crop, conveying system "holds" on to the straw and feeds only the panicles into the thresher
- Threshing drum tip speed 15 m/s
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- High mobility
- Can operate in small fields
- Less power required for threshing/cleaning · Ideal for hard-to-thresh varieties
- Straw cutting/chopping is easier
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- High Cost
- Low throughput
- Pick-up reel not suited for indica and other high-shattering varieties
- Complex machine
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Axial Flow combine
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- Similar to Conventional combine harvester, except an axial flow type thresher is used.
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- High Throughput
- Axial-flow threshing system ideal for tropical conditions
- Works with Basmati rice
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