By: Julianne Mason, Restoration Program Coordinator, Forest Preserve District of Will County
We have been using rice hulls as a carrier for our native seedings and loving the results! I first got the idea to try rice hulls from this USDA technical note [link to https://www.nrcs.usda.gov/Internet/FSE_PLANTMATERIALS/publications/idpmctn11458.pdf] I’ve tried various carriers over the years, primarily cereal grains like annual oats and rye, but here’s why rice hulls seem to work well:
- Rice hulls are light and fly out of the broadcast spreader about as far as native seed. More aerodynamic carriers like annual oats fly farther and give the operator a false sense of how wide the native prairie seed is being spread;
- Rice hulls seem to keep very small seeds (like rushes, wool grass, etc.) from falling out of the seed mixture all at once, and make them more evenly distributed across the field. This is especially beneficial for wetland seed mixes, which tend to have a lot of small seeds;
- Since they are light, rice hulls are a much nicer carrier for hand broadcasting. Also, less weight in the broadcast spreader makes it less likely for pins to shear;
- For our minimally cleaned prairie seed, rice hulls help the fluffy, stick-filled mass of seed to flow better through the seeder, and they reduce bridging and clumping; and
- Rice hulls are cheaper than cereal grains, when you just need a carrier and not a cover crop.
Here in the Midwest, unbroken rice hulls are available in compressed 50 pound bales directly from Riceland or from various on-line distributors like A.M. Leonard. We’ve been using 10 pounds of rice hulls per acre as a carrier for initial seedings, and 5 pounds of rice hulls per acre for lighter overseedings. Also fabulous: mixing the seed and rice hulls in a concrete mixer, which works really well!
Caption: Sorting bags of seed for mixing.
Caption: We used to mix seed by hand, mixing it with pitch forks and shovels on a concrete floor. A very dusty job!
Caption: The rice hulls are compressed and expand when the bale is opened. I highly recommend putting the rice hull bale in a 55-gallon plastic drum before slashing the sides of the bale open with a knife.
Caption: Photo of our restoration ecologist, Nick Budde, loading native seed and rice hulls in the concrete mixer.
Caption: We keep a poly bag strapped over the mouth of the concrete mixer while the seed is mixing. It keeps seed and dust from flying out.
Caption: Once mixed, the seed and rice hulls are dumped out into the poly bag.
Caption: View of rice hulls mixed with very clean seed bought from a commercial nursery.
Caption: View of rice hulls mixed with our minimally processed native seed.
Caption: View of seed and rice hulls broadcast onto snow cover.