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K-State Agronomy eUpdates

Department of Agronomy

Kansas State University

1712 Claflin Rd.

2004 Throckmorton PSC

Manhatan, KS 66506

785-532-6101

agronomy@ksu.edu

Extension Agronomy

Fall planting of smooth bromegrass pastures


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, there is 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.
 

https://webapp.agron.ksu.edu/agr_social/lib/Filemanager/userfiles/07282017/eUpdate07282017-A04-F04.gif

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 2).

https://webapp.agron.ksu.edu/agr_social/lib/Filemanager/userfiles/07282017/eUpdate07282017-A04-F02.gif

Figure 2. Optimum seeding dates for smooth brome in Kansas. Map from K-State Research and Extension.

 

Winter and spring plantings are not recommended on droughty claypan soils because smooth bromegrass will not survive if a hot, dry summer follows planting. Establishment of cool-season grasses is most successful with late summer or fall plantings. Adequate time must be allowed for summer tillage (if no-till is not the plan) and soil moisture storage.

Good weed control is essential. Control germinating weeds by light tillage operations or burndown applications of glyphosate. When 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. Prepare the ideal seedbed 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, as acidic soils severely limit forage production. 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. Apply and thoroughly incorporate any needed lime to a soil depth of six inches as far ahead of planting as possible (6 – 12 months before planting).

Nitrogen. Nitrogen (N) recommendations for new seedings of smooth brome is shown in Table 1. Applying 30-40 pounds of N before seeding will help ensure vigorous establishment of brome. Nitrogen could be applied with needed phosphorous (P) and potassium (K) and incorporated prior to seeding or broadcast after planting.

Phosphorous and Potassium. Soils in Kansas vary in levels of P and K present. A soil test is essential to determine requirements for these nutrients. Based on the soil test, addition of P and K will help establish smooth brome stands and ensure subsequent growth. Table 1 lists recommendations for P and K when establishing new stands of smooth brome. Broadcasting and incorporating recommended rates of P and K during seedbed preparation is the most desirable practice. Applications of P and K may be also be applied with the drill at seeding, and in-furrow fertilizers significantly increase forage production due to the readily available nutrients. Avoid placing more than 20 pounds per acre of N plus potash in direct contact with the seed at planting.
 

Table 1. Nutrient recommendations for new seedings of smooth bromegrass. Source: C402 Smooth Brome Production and Utilization, K-State Research and Extension.

Nutrient

Recommended rates

Nitrogen

30-40 lbs/acre

Phosphorus

Soil test level (ppm P)

 

Very low

(0-5)

Low

(6-12)

Medium

(13-25)

High

(26-50)

Very high

(51 or more)

 

60-80 lbs/acre

40-60 lbs/acre

20-40 lbs/acre

None

None

Potassium

Soil test level (ppm K)

 

Very low

(0-40)

Low

(41-80)

Medium

(81-120)

High

(121-160)

Very high

(161 or more)

 

80-100 lbs/acre

60-80 lbs/acre

30-60 lbs/acre

0-30 lbs/acre

None

 

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. Use higher seeding rates 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 harvested 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 prone to erosion or to obtain a return from the field the first year.

Grazing new stands

Protect new stands of smooth bromegrass from grazing until the grass is well established – at least three leaves with collars and crown roots establishing. If there is no crown root system established, cattle may pull the entire plant and reduce the stands. With proper management, fall seeded smooth bromegrass usually can be grazed the next year. Consider light grazing with haying at the bloom stage the first spring. Do not graze spring seedings 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, 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

Romulo Lollato, Extension Wheat and Forages Specialist
lollato@ksu.edu