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Calf prices in the spring had many cow-calf operators optimistic about the next several years and possible herd expansion. Widespread drought in the Corn Belt, however, has resulted in higher feed prices, which had a negative effect on feeder cattle prices. In Kentucky, the early summer drought also forced many operations to consider reducing herd numbers, and/or purchase additional feed. The drought has negatively impacted the second cutting of hay, which should result in higher hay prices this winter.
Recent rains have improved pasture moisture conditions in many areas, which may provide an opportunity for cattle producers to reduce winter hay requirements by applying nitrogen on selected pastures to stockpile for fall and winter grazing. By increasing total pasture production during this period, the grazing season can be extended and the amount of hay reduced. Higher hay prices that are likely this winter make the value of the additional grazing days higher than was seen last year.
The primary cost associated with fall fertilization is nitrogen, the price of which has increased significantly from a year ago. Urea, the common form of nitrogen used, is ranging from $750 to $800 a ton ($.82-.87/unit). The ultimate decision is whether the value of the additional grazing days added through fertilization exceeds the cost. Because soil moisture conditions are highly varied throughout the area, those areas that have received more rainfall will offer the best opportunities for applying nitrogen and stockpiling.
Stockpiling can be defined as growing pasture for later use. In Kentucky, that typically means applying nitrogen to tall fescue pastures in August, letting them grow through the fall, and then grazing during late fall and early winter. Other cool-season grasses also respond to fall nitrogen applications, but this discussion focuses on tall fescue since it shows a higher nitrogen response and stockpiles better for winter grazing.
The best pastures to target are those with the thickest stands of fescue. Fescue responds extremely well to nitrogen applications in late summer and has an amazing ability to retain its nutrient value through winter. Targeted pastures should have low concentrations of weeds and low amounts of clover, since legumes do not stockpile well after frost and the yield benefit of added nitrogen is less than in pure fescue stands. Moreover, nitrogen has the potential to reduce the clover component of the field as additional fescue growth competes with legumes. A good rule of thumb is that where clover makes up more than 20 percent of the stand, the short-term yield increase from nitrogen typically will not outweigh long-term forage quality and nitrogen fixation benefit of the lost clover.
Pastures should be grazed or mowed to reduce fescue height to two to three inches during early to mid-August. Remove animals before overgrazing occurs or initial regrowth will be slow. Grazing or mowing removes low-quality summer growth and allows the plant to produce high quality leaves. Assuming there is adequate soil moisture, a considerable amount of growth occurs in four to six weeks, but waiting eight to 12 weeks before grazing is preferable.
The optimal time to apply nitrogen is early to mid-August. Prior applications may encourage growth of weedy grasses such as crabgrass. Waiting until September reduces the efficiency of nitrogen conversion into plant growth. For example, one Kentucky study showed that nitrogen conversion efficiency (pounds of dry matter fescue growth per unit of nitrogen) was 27:1 on Aug 1, 26:1 on Aug 15, 19:1 on Sept 1, and 11:1 on Oct 1. Therefore, when nitrogen application is delayed until September or beyond, the optimal application rate decreases, and you should carefully consider the benefit of increased fescue growth compared to the cost of purchased hay.
Nitrogen response efficiency also depends on soil moisture. Without rain and/or adequate soil moisture, nitrogen response will be low, but even with small amounts of rain, tall fescue has an amazing potential for fall growth. In areas that are exceptionally dry, applying nitrogen can be somewhat of a gamble in terms of the response.
Traditional “stockpiling” involves keeping cattle off the pasture until late fall, but this practice may be difficult when pasture production is low. If forage is needed, nitrogen-fertilized pastures can be grazed in early fall, but it is recommended that cattle be kept off the pastures for at least a month. An alternative strategy is to feed hay during the stockpiling period to supplement the pastures cattle are on.
Besides the application of nitrogen, it is important stockpiled fields be limed and fertilized with P and K to acceptable levels. Where possible, stockpiled tall fescue fields should be strip grazed and stocked heavily enough to graze down each paddock in seven to 10 days or less. This allows the forage to be efficiently utilized without excessive trampling and waste. Because tall fescue does not re-grow in winter, a back fence is not needed when strip grazing stockpiled growth.
Greater detail of the stockpiling process can be found in the UK extension publication AGR-162 “Stockpiling for Fall and Winter Pasture” which can be found at: www.ca.uky.edu/agc/pubs/ agr/agr162/agr162.pdf or at the Hardin County Extension Service office.
Last call for Biltmore reservations
The absolute deadline to sign up for the Hardin County Cattlemen’s Association’s chartered motor coach tour to the Biltmore Estate is Friday. The tour is scheduled for Sept. 24-26. For the trip’s complete itinerary and cost per person, call the Extension Office at 270-765-4121.
Doug Shepherd is a Hardin County Extension agent for agriculture and natural resources.