Wildlife management along the Platte River
Robert Wilson, Professor Emeritus, Panhandle Research and Extension Center, Scottsbluff
As the North and South Platte Rivers flow through Nebraska they have created rich riparian areas adjacent to the river. Some of these areas have been colonized by invasive weeds, some are used for livestock forage, and many are managed for wildlife.
Landowners have made substantial investments in these properties to control invasive plants. After plant suppression the challenge for land managers is to introduce more desirable plant species that can help restore the land to a more sustainable state. Introducing perennial grasses, legumes and forbs can provide forage for grazing, wildlife and competition with invasive plants.
Information is available from many sources on seed mixtures to plant for grazing livestock, wildlife habitat and weed suppression. Landowners should look for information that is research-based and applicable to Nebraska.
Reading an article on the virtues of a plant that grows well in the southern United States may not be applicable to Nebraska. Invasive weeds have been introduced in Nebraska with good intentions, but later have turned out to be a mistake (wild proso millet, Russian olive, salt cedar, and reed canarygrass are examples).
Canada, musk and Scotch thistles can invade disturbed riparian areas after shrub removal. Birds eat the thistle seeds, roost in the shrubs and the seed is deposited in the soil under the drip line of the shrub. Therefore part of the shrub removal program should include thistle control and planting of desirable competitive grasses.
Studies conducted along the North Platte demonstrated the value of suppressing thistles with herbicides and then planting perennial wheatgrasses, which, once established, continued to suppress thistles.
In some situations the land manager may want to replace existing pasture grasses with more palatable and more wildlife attractive plants. This approach has become more attractive in recent years and has launched land managers into disciplines of agronomy, animal nutrition and wildlife management.
In the early 1930s wildlife food plots were being established to improve the health and attract wildlife. It was during this period that state wildlife agencies were trying to reintroduce deer, turkeys and game birds onto public and private lands. Wildlife food plots were an important component of restocking programs.
Research on grasses, legumes and forbs increased and an extensive database was established on how wildlife and domestic animals responded to different plants.
Researchers in New Zealand examined the effects of grazing deer on forage chicory compared to a mixture of perennial ryegrass and white clover. Deer grazed on forage chicory had reduced quantities of internal parasites, and therefore increased the productivity of the animals.
In the United Kingdom, researchers found helminth parasites were reduced in lambs grazing a forage chicory and birdsfoot trefoil mixture compared to lambs grazing ryegrass and white clover. In Canadian studies, conducted over three years, a mixture of orchardgrass, white clover and forage chicory produced greater dry matter yields than orchardgrass and white clover alone.
Studies conducted in western Nebraska demonstrated that a mixture of orchardgrass, white clover and forage chicory produced 3 tons of forage (12 percent moisture) with a protein content of 16 percent. These studies suggest that the introduction of mixtures of plants can increase forage production and benefit animal health.
Radishes and turnips are included in many wildlife seed mixtures and have been used for fall and winter grazing by cattle. Studies conducted in western Nebraska demonstrated that if given free choice deer preferred fodder beet to turnips or radishes. About half of the root of fodder beet is above ground, making it much easier for deer to graze and depending on the variety the dry matter content of the root can range from 12 to 20 percent. Fodder beet can tolerate sandy, high- pH soils and its long taproot allows it to utilize water from several feet in the soil.
The drought tolerance of grain sorghum and the ability to use several low cost herbicides for in-crop weed control make grain sorghum a good choice for upland bird and deer food plots. Grain sorghum can be successfully planted in areas with a dense weed population and over time with proper management reduce the weed seed population in the soil.
Wildlife management continues to evolve with the introduction of new plant varieties, increased interest in wildlife nutrition and a healthier deer population.
Robert Wilson can be reached at rwilson1@ unl.edu.