Flyways and Wetland Rotation

Flock of snow geese on unflooded farmland in Skagit ValleyPhoto: Mesa Schumacher

Flock of snow geese on unflooded farmland in Skagit Valley
Photo: Mesa Schumacher

Farmland gain across the world often means habitat loss of wetlands – important habitats for migratory birds. An interesting project proposed adding an old crop to the regular rotation on a number of farms originally won from deltas and estuaries: namely, the crop of water. I picture a watery mosaic in flux, with changing colors of visiting bird flocks instead of green grains. It’s easy to forget that less than a century ago, many of the areas we now associate with large farms were plains and deltas.

For some farms along well-known migratory bird flyways, farmers agree to let their fields flood as part of a yearly crop succession, rather than trying to keep the fields dry and/or irrigated year-round. The migratory birds are provided with link in a geographic chain, allowing them to land and feed. What’s interesting is that the farmers gain, as well. The flooding has led to increased nutrients in the ground, a reduction in weeds, and overall soil improvement.

The Nature Conservancy (TNC), which initiated the plan in cooperation with a consortium of partners, worked together with farmers in the Skagit Valley, Washington. In California’s Central Valley, TNC purchased farmland for the wetland experiment. The plan doesn’t work for all kinds of fields, crops or farmers; for example, it works best in grain fields, but orchards and vineyards that have taken over old flyway areas aren’t suited for annual flooding. Still, many farmers have reported no net loss in having a water crop in their rotation, and overall satisfaction with the routine.

In the Skagit Valley, Washington, over a dozen species of shorebirds have returned to land and feed on migratory routes lost to them during the course of the 20th century. Similar projects are underway elsewhere around the world.


The Nature Conservancy: Farming for Wildlife (Washington State)

National Geographic articles: Field flooding in California here and in Washington State here

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