When it’s time to harvest your grass crop, your combine settings can significantly influence the quality and success of your final result. Grass seeds are lightweight and fragile, so careful handling is crucial to minimize damage and maintain seed integrity throughout the process. Both conventional and rotary combines are suitable for harvesting grass seed, though conventional systems typically leave behind better-quality straw for baling.
Starting Settings for Timothy, ARG, PRG, and Tall Fescue #
For crops such as timothy, annual ryegrass (ARG), perennial ryegrass (PRG), and tall fescue, we recommend beginning with the following baseline settings:
- Fan speed: 400–600 rpm
- Concave clearance: Backed off to a setting similar to canola
- Cylinder/rotor speed: Around 600 rpm
- Clean sieve: Slightly open to reduce the amount of material sent back for re-threshing
These are starting points. Once you begin combining and have a steady seed flow into the grain tank, stop and inspect your sample.
Evaluating and Adjusting Your Sample #
Expect your sample to appear dirtier than that of a typical cereal grain crop—that’s normal. If your grain tank sample looks unusually clean, check behind the combine for signs of seed throw-over. Then, assess the seed in your grain tank for any cracking or visible damage to seed coats.
Based on what you observe, make adjustments to your settings as needed. This fine-tuning process is critical and should continue until your machine is dialed in for optimal performance.
Seed moisture content can also influence your results. If moisture is 14% or higher, it may lead to poor separation or sample quality. Ideally, aim for 12% moisture—this is considered dry for grass crops and will ensure good storage and viability. If moisture is slightly high, the crop will often continue to dry down throughout the day.
Special Considerations for Crested Wheatgrass #
For crested wheatgrass (CWG), your combine settings can largely mirror those used for wheat:
- Concave and rotor/cylinder speed: Similar to wheat
- Fan speed: Around 400–600 rpm
- Clean sieve: Slightly open to closed
CWG can be difficult to thresh thoroughly, as it requires breaking apart spikelets to reduce the number of doubles and triples ending up in the grain tank. In this case, think “hard and fast”—your combine should be aggressive enough to ensure clean separation.
Not sure if your combine is set up just right for your grass seed crop? Connect with your local BrettYoung Seed Production Specialist—they’ll walk you through adjustments and help set you up for a successful harvest.
