It’s hard to imagine cold mornings in the duck blind during the heat of the summer, but duck hunting success on those cold mornings might depend on what is done during the summer. Some of the best duck hunting is a result of abundant food, and the most important foods are primarily aquatic plants. Since most aquatic plants grow during the summer, management for those plants should be done at that time. There are a few options when managing for aquatic plants. One option is to manipulate water levels to manage plant communities. Another option is to passively work with what nature provides. Both methods have their positives and negatives.
If water levels can be manipulated, emerged and shoreline plant communities can be more productive for waterfowl. Timing of water level drawdowns can encourage different plant communities. For instance, an early drawdown in the first 45 days of the growing season usually encourages smartweeds. However, a later drawdown in the growing season usually encourages millets and other grasses. If possible, the best option is to draw down only a portion of an area early to encourage certain plants, and then draw down another portion of the area later in the growing season to encourage another plant community to increase plant diversity. The ability to manipulate the water level also allows a manager to control problem species such as cocklebur, which does not tolerate flooding as well as many desirable waterfowl plants.
If desired plant species are not present, they can be planted and managed. Grazing, burning and light disking can also be used to promote desired plant communities in wetland areas. It is not recommended to drain an impoundment in the Southern Great Plains when there is no ability to re-flood it due to unreliability of timely rainfall to refill the impoundment before fall migration.
If water levels cannot be drawn down and raised at will, aquatic vegetation can still be encouraged and managed. Many submerged plants are food for waterfowl, such as southern naiad, coontail and long leaf pondweed, and can be managed in an impoundment with relatively permanent water and somewhat static water level. These plants are also preferred foods of grass carp, so establishment and growth could depend on the presence of this herbivorous fish. These plants can be transplanted into water bodies when not present, but be careful to not introduce any unwanted plant species. During summer, there is usually a natural drawdown due to evaporation, which exposes the shoreline. Emerged and shoreline plants, such as smartweeds, sedges and others, germinate in the moist soil along the shoreline, and some tolerate flooding if the water level rises. These plants may be present and grow naturally, but seeding or transplanting may be necessary. Japanese millet is a popular plant to broadcast onto moist soil and takes about 60 to 90 days to mature. However, it is difficult to establish such plants when cattle are allowed free access to an impoundment. This type of management usually requires little work but may not attract as many waterfowl as more active management.
Active management of plant communities may attract more waterfowl, but it requires more labor and infrastructure than working with submerged aquatic vegetation and natural drawdown during summer. When managing for waterfowl, aquatic vegetation is one of the most important things to have to attract waterfowl to an impoundment.
Read more in the July issue of Oklahoma Farm & Ranch.