All in a day's work for soil, water district
BECKER COUNTY - Controlling invasive plant species in one township, planting trees for a windbreak in another, and constructing a grassed waterway in another -- it's all part of a day's work at the Becker County Soil and Water Conservation District.
Last Tuesday, about 40 interested spectators including farmers, county officials and ag professionals got a chance to see some of those projects up close, as the SWCD hosted its 2008 Invasive Species & Conservation Tour.
The SWCD began providing the county's ag inspector services about four years ago. SWCD Administrator Brad Grant and his staff recently secured a two-year grant from the National Fish and Wildlife Foundation to establish a Becker County Cooperative Weed Management Program (CWMP) to combat invasive weed species in the county.
Known as the "Pulling Together Initiative" (PTI), this program will focus on the control or elimination of five main species of invasive plants: Crown vetch, or axseed; common tansy; leafy spurge; spotted knapweed and wild parsnip.
So why are these four species deemed to be particularly noxious?
Wild parsnip, as explained by Assistant Becker County Ag Inspector Marsha Watland, is very different from its domestic counterpart. It secretes a white, milky sap that has been identified as poisonous. When human skin -- and that of some livestock as well -- is exposed to this sap, it will react with sunlight to create blisters similar to a third degree burn, Watland noted.
And unfortunately, unlike poison ivy, everyone is susceptible to its effects. This plant can be controlled through the timely application of herbicides such as Telar, Escort and Overdrive (or a combination thereof).
Like wild parsnip, leafy spurge is poisonous to horses and cattle, and can cause lesions and irritate an animal's mouth and digestive tracts.
This particular species can be controlled biologically, through the introduction of the leafy spurge beetle into it is ecosystem. Since 2006, the county has placed 238,000 beetles on 31 sites.
Spotted knapweed, meanwhile, secretes a toxin in its roots that kills off all other plants within its root system. Though it can be controlled biologically by the use of weevils, it can take up to 8-10 years for a weevil harvesting site to be developed.
However, an infestation can take up to three years to control through the use of a herbicide, Watland noted.
The toxic properties of the common tansy are cumulative, and consuming or even handling these plants can cause illness, convulsions and even death. This plant is also toxic to horses and cows, though not to sheep or goats. Herbicide application is effective, but may need to be repeated, while hand pulling and mowing will reduce seed production, but root fragments will still sprout.
The final species on the list, the crown vetch, is commonly found along woodland edges, gravel bars along streams, on roadsides and other right-of-ways. Its seeds can also live for 15 years in the soil. This species is deemed a "serious ecological threat that invades prairies and dunes." Herbicides are the most effective means of control.
To find the most effective method of long-term treatment, the PTI partners have begun implementing an integrated pest management, or IPM, approach that uses not only chemical and biological, but also mechanical and cultural control methods.
If given enough time, native prairie grasses and forbs will also become resistant to some forms of invasive species, though some, such as crown vetch, are truly invasive and need to be controlled using an integrated approach.
The second part of the SWCD tour focused on several conservation projects that the agency has been involved in, such as the shoreland restoration project on the shore of Boyer Lake at the Sunnyside Care Center.
This project, completed last year, involved the introduction of 66 different native plant species as well as the installation of rip rap and matting material. The ultimate aim was to repair erosion damage and prevent further loss of shoreline.