2008 Aerial Cover Crop Seeding Demonstration
Jeff Koster, Hiawatha Valley RC&D coordinator obtained a grant from the Driftless Area Initiative to do a demonstration on aerial seeding of cover crops. The goal was to generate interest in use of fall seeded cover crops for erosion control. Other goals included comparing establishment and growth of conventionally seeded and aerially seeded cover crops.
We had estimated a cost of $30/ac for the seed and helicopter, plus labor is needed on the ground to load the helicopter. Jeff Koster indicated the grant would cover 50% of cost to seed two 20 acre fields and 50% of any cost for holding a demonstration. The cooperators and the Mower SWCD agreed to provide the 50% local match required.
The sites had to be located in the Driftless Area, which includes the Root River and Upper Iowa watersheds in Mower County. There was a September 30th 2008 deadline to complete the project.
In 2008, Fillmore SWCD hired Terry John's Aviation Service to do the seeding on a number of farms in Fillmore County and included the Mower County site. Doug Keene, Fillmore SWCD Technician, indicated that Terry John's Aviation has several helicopters and was interested in working with the SWCD’s to promote aerial seeding. The cooperator in Mower County was Grass Lunning Simmentals, LeRoy, MN.
Prior years, Grass-Lunnings have seeded rye conventionally after silage harvest in early September. When seeding conventionally, they fertilize with nitrogen, potash and/or manure. There is not enough fall growth on conventionally seed rye for grazing, but the field is available for grazing in mid April until soybeans are planted in late May.
The conventionally seeded rye was grazed starting on April 17 in 2007 and on April 22 in 2008; when the rye was approximately 6” tall. Each 30 acre field will support about 50 pairs (cow with calf). After grazing the rye is sprayed with round-up 3 days before planting, and then tilled to loosen compaction from the cattle. This is typically the last field they plant to soybeans in late May.
In 2008, two 30 acre corn silage fields were selected for the demonstration. 20 acres in each field was seeded aerially into the standing corn, with the remaining 10 acres was to be seeded conventionally after harvest. The helicopter flew at 55mph with the seeder hanging from helicopter on cables. (See pictures) The seeding operation covers approximately a 100ft wide swath. The seeder holds 16 bags of seed per load and it only took 15-20 minutes to seed two 20 acre fields. This compares to 3-4 hours to dig with field cultivator, seed with terragator and 1 hour to drag in seed in conventional seedbed. Seeding was completed August 28th and the LeRoy Independent did story with photos of the helicopter seeding the field.
The seeding was done following a drought of over 8 weeks without substantial rain. Two weeks after seeding, the area received some light rain, consisting of approximately 0.1” of rain each day for three days combined with cool overcast conditions. The damp weather caused the rye to germinate and develop a small root but there was not adequate soil moisture to sustain the seedlings. The following week was dry, windy, and sunny and the warm dry conditions killed any rye that germinated.
Remaining kernels were tested for germination in a wet paper towel, and failed to grow, so the seeding was destroyed and the entire 60 acres was seeded conventionally after silage harvest.
The aerial seeding completed in Fillmore County in areas with adequate soil moisture grew well.
