Cover Crops: Can they help reduce High Path Avian Influenza?

One of the most significant risks for South Dakota and western Minnesota poultry producers is the swarms of snow geese that descend on us during the spring migration. This year, the birds tested were highly positive and shedding disease at an alarming rate. Many different intervention strategies were employed, including sound cannons, dogs, and other methods to move the geese onwards to the north or at least away from their barns. Maybe there’s something else we can do? Perhaps we can use cover crops like oats to deter them from landing? We can’t plant everything in cover crops, but maybe we can manage the area directly around the barns and make them less inviting for waterfowl.

Cover crops have multiple benefits already; they help reduce erosion, moisture loss, and nitrogen neutral over time. There is a cost to using cover crops. Seed, more passes with equipment resulting in some fuel and wear and tear, and some initial upfront nitrogen costs are a consideration, yet those costs can be mitigated. Depending on your area, you may qualify for Natural Resources Conservation Service funds via some of their programs. In many cases, there’s a crop insurance premium reduction that can help you defray the cost of seed and planting. As for the nitrogen, think of it as a bank. You are depositing some nitrogen in a savings account for next year when the cover crop decays in the field. While it is unavailable for a year, it will be back the next year.

Geese dislike tall grasses. There is nothing for them to eat in mature grass situations, and the tall grass interferes with the ability of the birds to take off. Geese need some time and space to run into the air, and with grass wrapping around their wings, they struggle to do that. They will avoid these situations. Like golf courses and shoreline homes, we can use this to our advantage. We can add taller cover crops to the location with some cool-season cover crops.

Consider the restrictive criteria when choosing the type of cover crop and method of planting. In South Dakota and western Minnesota, the climate is dryer and has a shorter growing window. Unless you’re already planting small grains or have silage corn around your barns, you may not have much time to get seed in the ground and have it grow to the 8+ inches that deter geese. We need something that can be broadcast (most likely via a plane), that can grow well if we get decent conditions before a freeze, and that will winter kill to eradicate a spring buffet for geese in the middle of our poultry sites.

I’m a poultry veterinarian, not an agronomist. I think it’s best when folks stay in their lane, which is why I reached out to David Karki, Ph.D. He is an Extension Agronomy Field Specialist with SDSU Extension. Dr. Karki suggested a few species that would winter kill, yet be tolerant of late fall cooler temperatures. The best plan for our purposes of repelling geese would be to use one or more species of oats, spring wheat, barley, rapeseed, and flax at leaf drop stage for soybean and half milk-line for corn. Of course, he also emphasized that the overall growth of these species when planted late-season (around the first week of Sept. or end of August) is directly dependent on the heat or sunlight and moisture we get. E.g., last year, we received good precipitation from late September and October. The temperature remained favorable long into the fall, which resulted in good growth of the cover crops and winter cereal crops planted in the fall. In contrast, dry weather and the early onset of cooler temperatures in the fall would drastically limit the fall growth.

Granted, we have never used cover crops for this purpose before, and we don’t know how successful it will be. What we do know is that what we are doing isn’t working as well as we would like, leaving us to consider trying some new novel ideas. I started talking about this at the Midwest Poultry Convention because a field on my commute had oats as a cover crop, and I did not see a single snow goose in that field, even while the other areas around it had countless white bodies landing in them. The whole industry is striving to remove some of the devastation we all experience when we lose a farm to HPAI. Everyone knows how awful that is. Perhaps we can reduce that risk by working together, and maybe one defense could be cover crops.