Aug. 20 marks the beginning of the optimum window to seed cool-season grasses in Kentucky.
It is also the ideal time to apply nitrogen in an effort to boost growth in September and October providing an accumulation of stockpile grass to graze during the onset of winter. This is an important date as anyone who utilizes land for grazing or hay production should have the goal of obtaining high nutrient quality, maximum utilization and stocking rates.
The way to fully utilize forage lands is to determine yield goals based on pounds of animal gain per acre. When the goal for forage yield is achieved, fertility, weed control and seed improvements are more affordable because land carrying capacity and production increase.
August is the month to plan and implement several forage related activities such as broadleaf weed control. Weed identification is key for fall weed control to determine if the target weeds are annual or perennial plants. The best time for herbicides on annual weeds is the spring and summer.
The timing for most perennial weeds is in the fall after they have completed their lifecycle and began to translocate stored energy reserves to survive the winter. Applying herbicide during this time is most effective as the plants readily absorb and move the herbicide down to the roots with the leaf nutrient reserves. Some examples of perennials we recommend treating in the fall are all of the thistle species, trumpet creeper, multiflora rose, common milkweed and chicory. These weeds can be treated now through October. It is best to wait until after harvest of adjoining fields with sensitive crops to reduce risk of drift injury.
Another step is soil testing. If you haven't tested fields in a year or two it is time to determine pH, phosphorus and potassium levels in the soil. Bring 2 cups of soil to our office to be tested through the University of Kentucky Soil Testing Laboratory at the research station in Princeton. The cost is $8. It is useless to apply additional seed or herbicide if fertility will not be maintained to support the desired forages and their ability to compete against weeds.
After fertility is corrected, the decision to apply additional grass seed such as a novel endophyte fescue or orchard grass can be made. We recommend a complete start over with novel endophyte, the fescue type that contains an endophyte that provides hardiness to the plant, but not the harmful effects of toxic endophyte found in KY31.
Novel endophyte seed is quite expensive. If KY31 fescue is going to remain in the field at the time of seeding, the field will continue expressing the characteristics of toxic endophyte, making the investment of novel types worthless. In highly erodible fields where some grass will remain simply for erosion control, seeding additional KY31 or a quality orchard grass variety would be suggested.
For fall seeding success, we suggest soil testing and applying recommended nutrients, then graze or mow the field close. Provide some type of soil disturbance via light tillage or a chain harrow type drag. Seed the field with 15-20 pounds per acre of tall fescue or orchard grass, then drag the field again providing as much seed to soil contact as possible. If available, no-till seeding equipment is ideal. Surface applied will work well as long as some seed to soil contact can be achieved. Rains in September and October will be needed to get new plants established. Fall seeding is much more likely to be successful than following the same procedure in the spring.
August is the month to stockpile pasture. Remove the herd and apply 90 actual units of your preferred nitrogen source on a thick fescue field that has been mowed or grazed. Data from University of Kentucky research found 90 units increased forage production by more than a ton per acre and protein levels by 5%.
For optimum efficiency feed some hay to supplement pasture the herd is on now. Keep the herd off the stockpile field as long as possible to provide the most return on your nitrogen investment. Then strip graze, providing only enough area for heavy stocking rates to have 7-10 days of forage. This eliminates excessive waste by trampling.