Now would be a good time of year to plan for fall seeding of smooth bromegrass pastures and/or hay meadows. If you start planning now, you should have plenty of time to have the soil tested, add lime and nutrients, especially phosphorus (P) and potassium (K) if necessary, and adequately prepare the firm seedbed so that you can have many years of productive forage from your pasture/meadow.
Figure 1. Smooth bromegrass pasture. Source: Smooth Brome Production and Utilization, K-State Research and Extension publication C402, https://www.bookstore.ksre.ksu.edu/pubs/C402.pdf
Planting dates
Smooth brome can be planted in late summer, early fall, winter or early spring (Figure 1).
Figure 2.
Winter and spring plantings are not recommended on droughty claypan soils because smooth bromegrass will not survive if a hot, dry summer follows planting. Cool-season grasses are established most successfully with late summer or fall plantings. Adequate time must be allowed for summer tillage (if you’re not planting it no-till) and soil moisture storage.
Good weed control is essential. Germinating weeds can be destroyed by light tillage operations or burndown applications of glyphosate. If you’re using tillage, it should be done no later than mid-August for a late August or early September planting. When moisture is available, several tillage operations may be needed to control weed growth and thus conserve soil moisture. Excess tillage may increase moisture loss and stand establishment failure.
No-till seeding of smooth bromegrass has emerged as a viable planting method, IF you do not need to incorporate lime or phosphorus to a 6-inch depth prior to planting. With no-till seeding, nonselective herbicides such as glyphosate are heavily relied upon to control existing weeds.
Seedbed preparation
Proper seedbed preparation is essential for a good stand. The ideal seedbed is firm, moist, free of weeds, and adequately fertilized and limed. Such a seedbed can be obtained by planning and using good techniques. Seedbed preparation on land suited for cultivation is relatively simple. For best results, minimize weed competition, obtain uniform seed distribution, plant shallow and evenly cover seed with soil. Many smooth bromegrass pastures have been established on sites that cannot be adequately tilled because soil is too shallow and/or slopes are too steep. On these areas, little seedbed preparation is possible.
Lime. Soil testing is essential to determine lime needs. Smooth bromegrass will grow on moderately acid soils, but does best on near neutral pH soils. Because smooth bromegrass stands can remain productive for 20 years or longer, correcting soil pH prior to seeding is essential. Needed lime should be added and thoroughly mixed to a soil depth of six inches as far ahead of planting as possible (6 – 12 months before planting).
Nitrogen. Figure 2 shows nitrogen recommendations for new seedings of smooth brome. Applying 30-40 pounds of nitrogen before seeding will help ensure vigorous establishment of brome. Nitrogen could be applied with needed phosphorous and potassium and incorporated prior to seeding or broadcast after planting.
Phosphorous and Potassium. Soils in Kansas vary in levels of phosphorous and potassium present. A soil test is essential to determine requirements for these nutrients. Based on the soil test, addition of phosphorus and potassium will help establish smooth brome stands and ensure subsequent growth. Table 1 lists phosphorus and potassium recommendations for establishing new stands of smooth brome. Broadcasting and incorporating recommended rates of phosphorus and potassium during seedbed preparation is the most desirable practice. Phosphorus and potassium also may be applied with the drill at seeding. Avoid placing more than 20 pounds per acre of nitrogen plus potash in direct contact with the seed at planting.
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Table 1. Nutrient recommendations for new seedings of smooth bromegrass |
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Nutrient |
Recommended rates |
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Nitrogen |
30-40 lbs/acre |
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Phosphorus |
Soil test level (ppm P) |
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Very low (0-5) |
Low (6-12) |
Medium (13-25) |
High (26-50) |
Very high (51 or more) |
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60-80 lbs/acre |
40-60 lbs/acre |
20-40 lbs/acre |
None |
None |
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Potassium |
Soil test level (ppm K) |
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Very low (0-40) |
Low (41-80) |
Medium (81-120) |
High (121-160) |
Very high (161 or more) |
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80-100 lbs/acre |
60-80 lbs/acre |
30-60 lbs/acre |
0-30 lbs/acre |
None |
Source: Smooth Brome Production and Utilization, K-State publication C402
Seed source and rate
High-quality seed of known germination and purity is important. Seeding rate depends on seed quality and method of seeding. When planting in a well prepared seedbed, 10 – 15 pounds of pure live seed (PLS) per acre is adequate. PLS refers to the amount of live seed of the desired species in a bulk lot. As an example, 100 pounds of bulk smooth bromegrass seed that has a germination of 90 percent and a purity of 95 percent contains 85.5 pounds of pure live seed (100 x .90 x .95= 85.5). Seeding rates of 15 - 20 pounds of PLS should be adequate if planting with a good no-till drill with good furrow openers, accurate seed placement, and good press wheels.
If a poor seedbed exists, or if the seed will be broadcast with shallow incorporation with a harrow, seeding rates as high as 20 pounds PLS per acre may be required to obtain satisfactory stands. Higher seeding rates should be used when smooth bromegrass is broadcast on the surface and covered.
Method of seeding
Drilling smooth bromegrass seed is the preferred method of seeding. Drilling ensures uniform seed distribution, accurate seeding rates, and uniform depth of coverage. For best results, smooth bromegrass should be seeded ¼ to ½ inch deep.
Broadcasting smooth bromegrass on the surface with shallow incorporation can result in good stands of smooth bromegrass. Wheat can be used as a cover crop in establishing a stand of smooth bromegrass. Start by broadcasting 20 pounds PLS of smooth bromegrass seed on the surface of soil prior to wheat seeding. As the wheat is drilled, the smooth bromegrass seed is covered. After the wheat is taken for hay or grain, smooth bromegrass is usually established, provided sufficient moisture is available for both crops. This is a slow establishment method, but it is desirable on soils subject to erosion or to obtain a return from the field the first year.
Grazing new stands
New stands of smooth bromegrass should be protected from grazing until the grass is well established – at least three leaves with collars and crown roots establishing. With proper management, fall seeded smooth bromegrass usually can be grazed the next year. Light grazing with haying at the bloom stage should be considered the first spring. Spring seedings should not be grazed until the following spring.
Weed control in new stands
Broadleaf weeds can be an issue in new stands of smooth bromegrass, but as with grazing, the new crop should be well established before using herbicides. Smooth bromegrass should have at least three leaves with collars and the crown root system should be established before any herbicide application is made. Weeds can be trimmed at 6-8-inches tall with a rotary mower in spring seedings until smooth bromegrass has developed the three leaves and adequate root system.
More information
For more information, see Smooth Brome Production and Utilization, K-State Research and Extension publication C402, at: http://www.ksre.ksu.edu/bookstore/pubs/c402.pdf
Stu Duncan, Northeast Area Crops and Soils Specialist
sduncan@ksu.edu
Doohong Min, Forage Agronomist
dmin@ksu.edu
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