– Dr. Chris Teutsch, UK Research and Education Center at Princeton
Fig. 1. Excessive rainfall and high livestock concentration in and around hay feeding areas can result in almost complete disturbance.
Hoof damage from livestock during the winter months can result in almost complete disturbance of desired vegetation and soil structure in and around heavy use areas. Even well-designed hay feeding pads will have significant damage at the edges where animals enter and leave. Highly disturbed areas create perfect growing conditions for summer annual weeds like spiny pigweed and cocklebur. Weed growth is stimulated by lack of competition from a healthy and vigorous sod and the high fertility from the concentrated area of dung, urine, and rotting hay. The objective of this article is to describe two approaches to revegetating these areas.
Regardless of the reclamation strategy that is employed, it is important to create an environment that will allow seeds to germinate quickly and uniformly, resulting in rapid canopy closure. This will help to inhibit weed seeds from germinating. Creating this environment starts with making sure that soil fertility is in the medium to high range, soil pH is 6.0 to 6.4, and preparing a fine, but firm, seedbed.
Plant cool-season grasses and legumes.
The first strategy is to seed cool-season grasses or a mixture of grasses and legumes in the spring. While this is commonly done, results are usually less than spectacular in most years. Seedings are normally delayed until late spring or early summer. Consequently, seedlings do not have time before the hot summer months set in. The second reason is that summer annual weed pressure is usually very high.
Summer annuals weeds like foxtail, goosegrass, spiny pigweed, cocklebur, and others actively compete with cool-season seedlings for light and water, often causing stand failures.
If a spring planting of cool-season grasses and legumes is attempted, there are several things that can be done to enhance, but by no means guarantee, success. These are listed below.
- Plant adapted forage species. Plant forages that are well adapted to Kentucky and the soils and drainage found on your farm. Tall fescue, red clover, and ladino clover are, by far, the best adapted and most versatile forage species for pastures in the Commonwealth. If this area is disturbed again, then investment in novel endophyte tall fescue varieties is not recommended. Information on the best adapted varieties for Kentucky can be found on the University of Kentucky Forages webpage.
- Consider leaving legumes out of the mix. While legumes are an important part of grassland ecosystems, herbicide options for controlling weeds in grass-legume mixtures are limited. Leaving legumes out will allow you to apply selective herbicides to control broadleaf summer annual weeds. For specific herbicide recommendation, you can visit with your local Extension Agent.
- Use the high end of the recommended seeding rate. Seeding rates are normally given as a range (Table 1). For spring seedings, make sure and use the high end of this range. Rapid canopy closure is critical to suppressing summer annual weeds.
- Plant as early as possible. Spring seeded cool-season forages should be planted starting in early to mid-March. Early plantings will have more time to emerge and form a canopy that can shade summer annuals weeds. Early planted grass seedlings will also have additional time to develop a root system that can sustain the new planting during the summer months.
- Plant in two directions. If drilling, cut seeding rates in half and plant in two directions. This will aid in obtaining quicker canopy closure, helping to reduce the germination of weed seeds.
- Use a shallow seeding depth. Small seeded cool-season forages should not be planted deeper than ½ inch. Make sure to check and recheck your seeding depth. Seeding deeper than ½ inch will delay emergence, result in uneven stands, and in many cases cause complete stand failure.
- Control broadleaf weeds in cool-season grasses. Once seedlings have four collared leaves, some herbicides can be applied. Always consult and follow label directions. For the most up to date information on using herbicides on new seedings, contact your local Extension Agent.
- Clip or flash graze new stands. Summer annual weeds compete very aggressively for light, water, and nutrients with cool-season grass seedlings. If not controlled, plantings will likely fail. The most effective control of competition is to flash graze paddocks before weeds get well established. Flash grazing is accomplished by placing a large number of animals in small areas for a short period of time. This reduces selective grazing and increases grazing uniformity.
Plant warm-season annual grasses
Figure 2. Sorghum-sudangrass (left) formed a quick canopy that was able to shade out summer annual weeds compared with forage (right).
The second strategy involves planting a summer annual grass in late spring or early summer. This strategy has a much higher probability of success than planting cool season grasses in late spring. Summer annual grasses, especially sorghum-sudangrass or sudangrass, have very rapid emergence and canopy closure. This will prevent summer annuals weeds from germinating and provide forage for grazing or harvesting during the summer months (Figure 2). Perennial cool-season grasses can then be reseeded under more ideal conditions in late summer or early fall.
The following tips will help to enhance your chances of success when using warm season annual glasses.
- Plant adapted summer annuals species. Always plant forages that are well adapted to Kentucky and the soils and conditions on your farm. Summer annuals that can be used to reclaim hay feeding areas include sudangrass, sorghum-sudangrass, pearl millet, and crabgrass. A description of these species can be found in AGR-229, Warm Season Annual Grasses in Kentucky.
- Use the high end of the seeding rate. Seeding rates are normally given as a range. (Table 2). Make sure and use the high end of this range. Even with summer annuals, rapid canopy closure is critical for reducing unwanted weed competition.
- Plant after soil warms. For summer annual grasses to germinate and rapidly emerge, soil temperatures at planting should be at least 60 degrees F. This should allow plenty of time to let hay feeding areas dry out and to get them smoothed up prior to planting. If there is a delay in planting the summer annuals after final tillage, it may be a good idea to do one more pass of light tillage to disturb any weed seedlings that may have germinated.
- Control broadleaf weeds. Once warm-season annual grasses are established, some herbicides can be applied to control summer annual broadleaf weeds. If cool-season perennials are to follow in the fall, make sure and check the label for reseeding restrictions prior to application. Always consult and follow label directions. For more information on using herbicides on summer annual grasses, contact your local extension agent.
- Grazing summer annual grasses. Allow taller growing summer annuals like sorghum-sudangrass and pearl millet to reach a height of 18-24 inches before grazing and stop grazing at 8-10 inches. Regrowth can be stimulated be applying 40-60 lb N/A after each grazing but the last. Crabgrass can be grazed once it reaches a height of 6 to 8 inches. Cattle should be pulled off once it has been grazed to a height of 3 to 4 inches. Detailed management recommendations on for individual summer annual species can be found in AGR-229, Warm Season Annual Grasses in Kentucky.
- Haying summer annual grasses. Allow taller growing summer annuals to reach a height of 30 to 40 inches before mowing. This will optimize yield and forage quality. If regrowth is desired, do not mow closer than 6 inches. Apply 40 to 60 lb N/A after each cutting, but the last. Crabgrass should be cut for hay at the late boot-stage. Care should be taken to not mow crabgrass closer than 3 to 4 inches. With the taller, thicker stemmed species, a crimping mower-conditioner will help the crop dry to safe baling moistures, although this may take some time. Ideally, summer annuals should be conserved as chopped silage or baleage.
- Reseeding cool-season grasses in the fall. Pastures with summer annuals should be sprayed with a non-selective herbicide in late summer to control any remaining summer annual grass and any weeds that have germinated. Use a no-till drill to plant cool-season grasses into the killed pasture area. More information on forage establishment can be found in AGR- 64: Establishing Forage Crops.
For more information on renovating pastures and no-till seeding techniques visit UK Forage Extension website at http://forages.ca.uky.edu/ or contact your local extension office.
FEATURED VIDEO
This month’s featured video is Assessing and Repairing Damaged Pastures by Chris Teutsch. This presentation was given at the Red Hill Farms, Lafayette, TN on March 15, 2019.
FEATURED PUBLICATION
This month’s featured publication is: AGR-255, Strategies for Reclaiming Hay Feeding Areas by Chris D. Teutsch and Kelly M. Mercier, Plant and Soil Sciences. UK Cooperative Extension Service, Lexington. It can be accessed by clicking on the link or visiting your local extension office.
FORAGE MANAGEMENT TIPS
