Updated: Sep 16, 2020
April 5, 2016 / GE Avoidance, GE Contamination, GMO Contamination Mi
Alfalfa (Medicago sativa)
In 2005 alfalfa became the first perennial GE crop to attain approved status in the U.S. Within a year of GE alfalfa’s initial commercial release, contamination had occurred in the commercial sector.
The Roundup Ready™ trait was identified in conventional non-GE plantings of alfalfa in Montana, Wyoming, and Idaho, as well as in feral populations of alfalfa sampled by Colorado State University Extension. In September 2013, GE contamination of conventional alfalfa hayfields in Washington state was also documented.
Perhaps this GE contamination is because current industry standards for alfalfa isolation were designed for varietal purity and not for avoiding GE contamination, and are simply not large enough.
The National Alfalfa & Forage Alliance (NAFA) adopted a series of best management practices for Roundup Ready™ alfalfa seed production in 2008, taking into account foraging distances for alfalfa’s common pollinators. NAFA’s isolation stipulations are: 900 ft. in the presence of leafcutter bees, 1 mile for alkali bees, and 3 miles for honeybees.
The Xerces Society for Invertebrate Conservation, however, recommends 5 miles between GE and non-GE fields. They double this distance in the presence of honeybees. Cross-pollination of non-GE alfalfa is much more likely to occur between two seed crops than between alfalfa hay crops. Though the latter is still possible.
Feral populations of alfalfa are a real concern. Known to crop up in roadsides and ditches, these feral plants can be more likely to act as sources of contamination than cultivated alfalfa stands. Original seed sources include seed spilling during transport, seed from harvested hay, and seed moved via birds.
Alfalfa seeds are small, hard, and capable of remaining dormant for years, potentially leading to future generations of volunteers if left in the soil. Alfalfa seed can also be spread by grazing animals, allowing for unintentional “planting” via their excrement.
Alfalfa plants themselves can also act as a source of genetic material; stem cuttings or crowns are capable of regenerating new plants. Its perennial nature makes containing GE genes even more difficult.
If you’re planting alfalfa this season and want to decrease your crop’s risk of GE contamination, read the full crop-specific chapter in Protecting Organic Seed Integrity: The Organic Farmer’s Handbook to GE Avoidance and Testing. The handbook is available as a free download.
Keep Your Alfalfa Seed GE-Free…
Identify potential points of contamination.Plant clean seed a minimum of 2.5 miles from GE sources. 5 miles is optimum.
Increase isolation distance to 10 miles in presence of honeybees.
If possible, plant larger fields (greater than 5 acres).
Control feral alfalfa near hayfields and seed fields.
Communicate with neighbors who are growing alfalfa hay to express how cutting their crops early would lesson potential cross-pollination with your seed crops.
Avoid renting pollinators previously used near GE alfalfa fields.
If renting pollinators, choose species that range shorter distances (i.e. leafcutter bees).Avoid seed mixing during harvest, cleaning, storage, transport, and sales.
Use dedicated equipment and facilities if possible. Otherwise, clean thoroughly between use.