After being delayed by the partial government shutdown the Bureau of Land Management has completed a large reseeding project in Idaho. The agency treated 52,000 acres of land that burned in wildfires during the last two years including portions of the 99,502-acre Grassy Ridge fire northwest of St. Anthony and other fires near Atomic City and Menan Buttes. Helicopters and fixed wing planes dispersed the seed.
Below is an excerpt from an article in the Idaho State Journal:
Experts on the subject say the best time to reseed is when there’s snow on the ground.
“If you have a sunny day when you’re applying, the seed will heat up and melt below the snow layer,” Ben Dyer, BLM fire ecologist, said. “You try to have it put down when a storm is predicted in the near future so you can cover it up with another layer of snow.”
If all goes well, the snow melts in spring and provides the seeds with wet soil to germinate and flourish. There is currently 6 to 8 inches of snow on most of the ground where the Grassy Ridge Fire occurred last summer, Dyer said. Dyer said the hope is that grass and sagebrush seed will establish itself before cheatgrass does and also help prevent soil erosion.
“We include a mixture of native grasses and forbs and we also have some introduced (seeds) that are a little more aggressive at choking out and competing against cheatgrass,” he said. “In the event that our native components don’t do well, at least we have that non-native component that has a little bit better chance.”
Replanting trees after a wildfire or logging operation is an extremely labor intensive and expensive task. Carrying a bag of seedlings and using a dibble bar or shovel across steep debris-covered terrain can wear out a human.
A new company, DroneSeed, has a solution. Use machines. They are designing a system around a swarm of drones that can plant tree seeds in places where they have a decent chance of survival. First they survey the area with a drone using lidar and a multispectral camera to map the terrain and the vegetation. Software then identifies the areas that have invasive species or other plants the landowner wants to eliminate and then a drone applies herbicide to only the patches that need it, rather than dumping pesticide over the entire landscape.
According to an article at TechCrunch, DroneSeed is still fine tuning the seed dispersing system, but the next step is to use artificial intelligence to sort through the mapping data to find microsites where a dropped seed is most likely to germinate.
Using a concept that has been around for a long time, they will coat the seeds with substances that will enhance its survival chances. The article explained that the company is very reticent to detail exactly what will be applied to the seed. In agriculture, seeds are often coated with polymers, fertilizers, or fungicides. Polymers can improve the flowability and plantability — if the weather is hot and humid, cool and damp, or dry — to get consistent seed drop.
One issue DroneSeed appears to be concentrating on is deterring animals from eating or removing the seeds. They are looking at adding capsaicin, a chili pepper extract, to the coating. A fertilizer, if included, would wash off during a rain and then supply nutrients to the seed as it germinates.
The drones they are using are off the shelf aircraft that DroneSeed guts and converts into a machine that fits their missions. They are referred to as “heavy lift” drones since they weigh more than the 55-pound maximum for more conventional drones. The FAA limits heavy lifts to 115 pounds. The company says they are the first and only company the FAA has approved to use drone swarms to dispense agricultural payloads (fertilizers, herbicides, and water).
The FAA classifies this exception as “precedent setting”, referring to the exceptional lengths DroneSeed has gone to prove out its ability to scale operations to larger payloads for multiple concurrent flights.
As you can see in the video below, the drones are used in swarms, with five to six drones being able to equal the production of one helicopter when spraying herbicides.
DroneSeed has worked for three of the five largest timber companies since 2017 spraying herbicides, but they are just getting into the tree seeding game. They missed the prime planting season this year but were able to apply seeds to a few small sites and should be in a good position next year to show off their results.