Ohio Agronomy Guide, 14th Edition

Bulletin 472-05

Chapter 7: Forage Production

R. Mark Sulc and David J. Barker

The forage industry plays a major role in Ohio agriculture. Approximately 30% of the total economic output from farming in Ohio is derived from meat and milk products ($2.4 billion). In Ohio there are 1.23 million cattle and calves valued at more than $1 billion. Ohio ranks 10th in the nation in number of milk cows (258,000 head), 30th in beef cows (262,000 head), and 12th in sheep and lamb inventory (140,000 head). About 36% of Ohio farms have cattle and calves. In 2003, nearly four million tons of hay were produced (17th in the nation) on 1.35 million acres. Pastures comprise more than 2.1 million acres of Ohio’s total farmland.

Forages are environmentally friendly. They protect soils from erosion, improve soil tilth, help reduce pesticide use, and enhance agricultural profitability. Forages are vital to Ohio agriculture, protect our soil and water resources, and add beauty to the state.

All forage crops respond dramatically to good management practices. Higher yields, better forage quality, and improved persistence result from paying attention to the basics of good forage management. The objective of this guide is to help producers achieve the high potential of forages grown in Ohio.

Perennial Forages

Species Selection

The selection of forages for hay, pasture, and conservation is an important decision requiring knowledge of agronomic characteristics, forage species adaptation to site and soil characteristics, and potential feeding value of forage plants. The intended use of forages, dry matter and nutritional requirements of livestock to be fed, seasonal feed needs, harvest and storage capabilities, and seasonal labor availability influence which species to grow.

Agronomic Adaptation and Intended Use

Tables 7-1 and 7-2 outline the agronomic adaptation and characteristics of some of the more important forages grown in Ohio. Because the choice of species is limited to those adapted to the soils on the farm, the soil adaptation factors in Table 7-1 should be studied carefully.

Useful soil information describing the limitations of a particular soil for forage production can be found in county soil survey books. Keep in mind that soil pH can be increased with lime; soil fertility can be improved with fertilizers and manure; and soil drainage can be improved with tiling. Soil drainage is usually the most difficult soil characteristic to modify.

The brief discussion of individual species presented here will also help in determining which species are best suited to a particular enterprise. Table 7-3 gives commonly recommended species to consider for general soil fertility classes and forage utilization methods. The information here is by no means exhaustive, but it does cover the most common forages adapted to Ohio conditions.

Pure Stands vs. Mixtures

The decision to establish a pure stand or a mixture should be made before deciding which species to plant. Advantages of pure grass or legume stands are simpler management, more herbicide options, and greater forage-quality potential. Pure legume stands decline in forage quality more slowly with advancing maturity than do grasses, providing a wider window of opportunity for harvesting good-quality forage.

Legume-grass mixtures are common in Ohio and are generally more satisfactory for pastures than are pure stands. Grass-legume mixtures are often higher yielding and have more uniform seasonal production than pure stands. Including legumes in a mixture reduces the need for nitrogen fertilizer, improves forage quality and animal performance, and reduces the potential for nitrate poisoning and grass tetany compared with pure grass stands. Including grasses in a mixture usually lengthens the life of a stand because they persist longer and are more tolerant of mismanagement than legumes. Grasses reduce the incidence of bloat, improve hay drying, are usually more tolerant of lower fertility, and compete with weeds more than legumes. The fibrous root system of grasses helps control erosion on steep slopes and reduces legume heaving. Growing grasses and legumes together often reduces the losses from insect and disease pests.

Mixtures for Hay and Silage

Keep mixtures relatively simple for hay or silage use; two to four species are usually sufficient. Hay and silage cutting schedules are easier to manage with simple mixtures. Select grass and legume species to build simple mixtures for hay or silage using the following criteria:

• Adaptation

  All species in the mixture should be adapted to the prevailing soil conditions (drainage, soil moisture-holding capacity, soil pH, fertility, etc.).

• Rate of establishment

  Combine species with fairly similar seedling aggressiveness. Persistent plant species are often the least competitive in the seedling stage. Excessive seedling competition in a shotgun mixture can prevent persistent and desirable species from becoming established. An exception to this rule is the use of companion crops, or fast-establishing short-lived perennial or annual species used to achieve quick ground cover. Small grains and annual or perennial ryegrass are often used for this purpose. Keep seeding rates of these temporary companions low to avoid excessive competition with the slower-establishing perennial species

• Time of maturity

  Species and varieties in a mixture should mature at about the same time and match your intended harvest schedule. There is considerable variation in maturity of grass species and varieties. Such information is often collected in variety testing trials.

• Management compatibility

  Select species that are well adapted to the intended management. For example, orchardgrass is compatible with alfalfa on a four-cut schedule because it regrows quickly, while timothy and smooth bromegrass are compatible with alfalfa on a more lenient three-cut schedule.

• Summer production

  Alfalfa produces very well during the summer months while birdsfoot trefoil and red clover generally produce less summer yield. Of the grasses, orchardgrass and reed canarygrass produce the best summer growth. Smooth bromegrass produces moderate to light summer aftermath, and timothy, meadow fescue, and perennial ryegrass are usually low yielding in the summer months. Moisture and temperature conditions affect aftermath production of cool-season grasses more than alfalfa.

• Variety Performance

  Use variety testing data to select species and varieties that have stable yield performance over multiple locations and years, which demonstrates good adaptation to a wide range of conditions. Performance over years demonstrates yield persistence with advancing stand age and is especially important for long rotations. For Ohio variety test data and links to data in other states, see: www.ag.ohio-state.edu/~perf/.

• Disease and pest resistance

  Select species and varieties with resistance to key insects and diseases for your soils. For example, Phytophthora root rot and Fusarium wilt resistance in alfalfa are very important on soils with sub-optimal drainage, while potato leafhopper resistant alfalfa is useful across all of Ohio.

• Forage quality

  Varieties with improved forage quality are available in some species, such as alfalfa. If high forage quality is very important, then select varieties based on this trait.

Mixtures for Pastures

Simple mixtures are desirable for hay and silage management, but recent studies demonstrate that complex mixtures of six or more species provide greater stability of forage production under grazing. Soil and environmental variability is usually high in pastures and, therefore, it is more difficult to predict which species will perform best across the variable landscape. Species dominance and spatial distribution in a pasture will be affected by variability in fertility, soil drainage, slope aspect (north or south facing), and animal traffic and grazing patterns, among other factors that influence the microenvironment. In addition, species vary in productivity during different seasons, i.e., between spring and summer grazing periods. Select grasses and legumes that fit the general soil conditions and management characteristics and that are not drastically different in palatability.

Seeding Rates

Table 7-4 gives recommended seeding rates for individual species in pure stands and for mixtures. Seeding rate recommendations are related to seed size, germination, seedling and established plant vigor, spreading characteristics, and mature plant size. For example, more seeds per square foot are recommended for species with low seedling vigor and smaller mature plant size (e.g., Kentucky bluegrass) in order to improve establishment success and competitiveness of that species in a mixture or against weed encroachment. Increasing seeding rates above the recommended levels does not compensate for poor seedbed preparation or improper seeding methods.

There is no reliable way to predict that a specific proportion sown will result in an equivalent proportion of established plants in a mixed species seeding. The seeding rates shown for mixtures are simply varying percentages of the pure stand seeding rate recommendation. Use your best judgment to adjust the seeding rate for each species based on the relative proportion desired of that species in the mixture (see shaded box below). Complex mixtures will often result in a higher overall seeding rate (in seeds per square foot) than simpler mixtures. This is simply a function of having more component species, each one seeded above a minimum level, to provide an opportunity for it to establish and compete in the microenvironments where it is best adapted.

Characteristics of Perennial Cool-Season Forages

Alfalfa (Medicago sativa L.)

Alfalfa is grown on about one-half of the total hay acres in Ohio. Where adapted, it is unmatched by any other forage as high-quality feed for livestock and as a cash crop. Alfalfa requires deep, well-drained soils with near-neutral pH (6.5 to 7.0) and high fertility for high yields. It should not be grown on soils with moderate to poor drainage. Alfalfa is best adapted to hay or silage harvest management. While it can be used in rotationally grazed pastures, it normally lacks persistence in permanent pastures compared with other legumes. Like most legumes, it can cause bloat. Alfalfa has good seedling vigor, excellent drought tolerance, and produces very well in the summer. Important insect pests on alfalfa include the alfalfa weevil and potato leafhopper.

To capitalize on alfalfa’s potential, select newer high-yielding alfalfa varieties with adequate winter hardiness and resistance to important diseases. Recent improvements in alfalfa varieties include selection for multiple disease resistance, forage quality, and high levels of resistance to potato leafhopper. Recent studies in Ohio have demonstrated that new varieties with multiple pest resistance provide higher yields and greater stand persistence with less weed invasion than older varieties with less disease resistance. Varieties are becoming available with improved tolerance to traffic. When selecting varieties, always evaluate performance data across multiple locations when possible. For more information on varieties, see the Ohio Forage Performance Trials, available at Extension offices and online at: www.ag.ohio-state.edu/~perf/.

Alsike Clover (Trifolium hybridum L.)

Alsike clover is a short-lived perennial legume that is tolerant of wet, acidic soils. Alsike tolerates soils with a pH as low as 5.0, which is too acidic for red clover and alfalfa. Alsike also grows better than red clover on alkaline (high pH) soils. Alsike tolerates flooding better than other legumes, making it well suited for low-lying fields with poor drainage. Alsike can withstand spring flooding for several weeks. A cool and moist environment is ideal for alsike clover growth; it has poor heat and drought tolerance, thus usually produces only one crop of hay per year. It is susceptible to the same diseases that attack red and white clovers. Its growth habit is intermediate between red and white clover. Alsike clover must be allowed to reseed to maintain its presence in pastures; otherwise it will last only about two years. Alsike clover has good palatability, but it can cause bloat and photosensitization in grazing animals.

Birdsfoot Trefoil (Lotus corniculatus L.)

Birdsfoot trefoil is a deep-rooted perennial legume that is best adapted to northern Ohio. Birdsfoot trefoil is tolerant of low-pH soils (as low as pH 5.0), moderate to somewhat poor soil drainage, marginal fertility, and soils with fragipans. Birdsfoot trefoil can withstand several weeks of flooding and tolerates periods of moderate drought and heat. Birdsfoot trefoil has poor seedling vigor and is slow to establish. Early spring seedings are generally more successful than late summer seedings. It is subject to invasion by weeds when grown in pure stands; therefore, it is best seeded with a grass companion. It produces excellent quality forage, has fair palatability, stockpiles well, and unlike most forage legumes, it is non-bloating. Birdsfoot trefoil should be managed to allow for reseeding, which will help maintain its presence in forage stands. It is intolerant of close cutting or grazing, has slow recovery after hay harvest, and is susceptible to root and crown rot diseases.

Empire-type varieties have prostrate growth and fine stems, making them better suited to grazing. European-type varieties are more erect, establish faster, and regrow faster after harvest. Thus, they are better suited to hay production and rotational grazing. Most of the newer varieties are intermediate with semi-erect to erect growth habit.

Kura Clover (Trifolium ambiguum Bieb.)

Kura clover is a relatively new species to Ohio. It is a perennial clover originating in Caucasian Russia. Kura clover has rhizomes, underground modified stems that spread new plants into empty spaces. It is a very hardy legume that is best adapted to long-term permanent pastures. It will tolerate continuous stocking and is very persistent once established. It has an extensive root system. In university tests, stand density improved over time. Superior animal performance on rotationally stocked mixed grass pastures containing Kura clover was associated with greater forage yield and nutritive value compared to red clover/grass pastures.

Kura clover tolerates low fertility, soil acidity, wet soils, and moderate flooding. Although it stops growing during a drought, its deep root system ensures excellent drought survival. Its major limitation is poor seedling vigor and slow establishment. It requires a specific Rhizobia inoculant. The forage grazed by livestock is primarily leaves (like white clover) and is very high in nutritive value. If sufficient grass is not present, it can induce bloat in ruminants. Its low-growing growth habit and high moisture content make it difficult to use for hay.

The first variety of Kura clover released in the United States was ‘Rhizo.’ Other varieties have followed, such as ‘Cossack’ and ‘Endura.’

Red Clover (Trifolium pratense L.)

Red clover is a short-lived perennial legume grown for hay, silage, pasture, and green manure. Red clover is better adapted than alfalfa to soils that are somewhat poorly drained and slightly acidic; however, greatest production occurs on well-drained soils with high water-holding capacity and pH above 6.0. Red clover is not as productive as alfalfa in the summer. It has good seedling vigor and is one of the easiest legumes to establish using no-till interseeding or frost-seeding techniques. Under Ohio weather conditions, red clover is often difficult to dry for hay storage. Harvesting for silage or including a grass in the stand helps overcome this problem. When grazed, red clover can cause bloat in cattle if sufficient grass is not present.

Medium red clover varieties can be harvested three to four times per year. Mammoth red clover is late to flower and is considered a single-cut clover because the majority of its growth occurs in the spring. Most of the improved varieties are medium types and have good levels of disease resistance to northern and southern anthracnose and powdery mildew. Several new medium red clover varieties have demonstrated good stand persistence for three or even four years in university trials (see: www.ag.ohio-state.edu/~perf/,2003 report).

White Clover (Trifolium repens L.)

White clover is a low-growing, short-lived perennial legume that is well suited for pastures. It can cause bloat in cattle if sufficient grass is not present for grazing. White clover improves forage quality of grass pastures and reduces the need for nitrogen fertilizer. White clover can be frost seeded or no-till seeded into existing grass pastures. It spreads by stolons. It has a shallow root system, so it does not tolerate prolonged dry spells and usually has lower summer growth. Although well-drained soils improve production, white clover tolerates periods of poor drainage. It can be managed for reseeding to improve persistence in pastures.

Large white clover types, also known as Ladino clovers, are more productive than the smaller type White Dutch or wild white clovers. Wild white clovers persist better under heavy, continuous grazing because they are prolific reseeders. Purchase seed of stated quality to be certain of obtaining pure seed of the white clover variety desired.

Crownvetch (Coronilla varia L.)

Crownvetch is a long-lived perennial that is most commonly used for soil erosion control, beautification, highway embankments, mine spoil areas, and other disturbed areas. It spreads by creeping underground rootstocks and has a deep taproot and numerous lateral roots. Crownvetch is best adapted to well-drained, fertile soils with a pH of 6.0 or above, although it is somewhat tolerant of moderately acid and infertile soils. It has slow seedling development, and seedlings are very sensitive to competition, so do not use a companion crop and provide good weed control during establishment. If planted with grasses, use less competitive grasses such as timothy or Kentucky bluegrass rather than orchardgrass or tall fescue. Animals do not readily accept crownvetch forage and must be acclimated to it. Good stands of crownvetch have been maintained under a two-cut hay harvest and under lenient grazing in Ohio (a three-inch stubble should be left).

Festulolium (Festulolium spp.)

Festulolium grass species are hybrids derived from crossing meadow fescue and ryegrass. They are bunchgrasses suitable for hay, silage, or pasture. The meadow fescue parent contributes midsummer growth, winter hardiness, and drought tolerance while the ryegrass parent contributes rapid establishment and forage quality. Winterhardiness of festulolium is lower than meadow fescue, but generally better than that of perennial ryegrass. Festulolium is best adapted to the northern half of Ohio and may be better adapted to southern regions of Ohio than perennial ryegrass. It grows especially well in the spring and produces palatable forage with high nutritive value similar to that of perennial ryegrass.

Festulolium yields well under good fertility when moisture is adequate. Like perennial ryegrass, it is a vigorous establisher. Because it is less winter hardy than other grasses, festulolium is best seeded in combination with other grasses and legumes. It can be grown on occasionally wet soils. Compared with orchardgrass, it is lower yielding, less competitive with legumes, and later to mature. Like orchardgrass, festulolium can withstand frequent cutting or grazing. It is difficult to cut with a sickle bar mower and is slower to dry than other grasses, so it is better suited for grazing, greenchopping, and silage harvesting than for dry hay.

Festulolium varieties can differ markedly in winterhardiness and recovery from winter injury. For permanent pastures, select varieties that are proven to persist under Ohio conditions.

Kentucky Bluegrass (Poa pratensis L.)

Kentucky bluegrass is a long-lived perennial grass especially well suited to pastures. Its low growth habit makes it less suited to hay and silage production. It forms a dense, tough sod under favorable conditions, providing good footing for grazing animals. It reproduces by seed and rhizomes. It tolerates close or frequent grazing. Kentucky bluegrass is one of the most forgiving grasses, able to tolerate and persist under a wide range of soil conditions and mismanagement, but it will respond and have better production under good management. Kentucky bluegrass grows best under cool and moist conditions and usually becomes semi-dormant during the summer. Planting good quality seed of forage Kentucky bluegrass varieties results in a more productive pasture than the naturally volunteering bluegrass.

Orchardgrass (Dactylis glomerata L.)

Orchardgrass is a versatile perennial bunch-type grass (no rhizomes) that establishes rapidly and is suitable for hay, silage, or pasture. Orchardgrass is probably the most productive cool-season grass grown in Ohio, especially under good fertility management. It has rapid regrowth, produces well under intensive cutting or grazing, and attains more summer growth than most of the other cool-season grasses. Orchardgrass tolerates drought better than several other grasses (Table 7-1). It grows best in deep, well-drained, loamy soils. Its flooding tolerance is fair in the summer but poor in the winter. Orchardgrass is especially well suited for mixtures with tall legumes, such as alfalfa and red clover. The rapid decline in palatability and quality with maturity is a limitation with this grass. Timely harvest management is essential for obtaining good quality forage.

Improved varieties of orchardgrass, with high yield potential and improved resistance to leaf diseases, are available. Maturity is an important consideration in variety selection, and a wide range in maturity is available among newer varieties. When seeding orchardgrass-legume mixtures, select varieties that match the maturity of the legume. The later-maturing varieties are best suited for matching the maturity of alfalfa and red clover and are easier to manage for timely harvest to obtain good-quality forage. In pastures, early-maturing varieties will often produce higher yields, but grazing management must be aggressive in the spring. Performance under grazing is being evaluated in several university variety trials and should be considered when selecting varieties for grazing.

Ryegrass (Lolium species)

Perennial ryegrass (Lolium perenne L.) is a bunch grass suitable for hay, silage, or pasture. It is best adapted to the northern half of Ohio. It has not persisted well in the southern half of Ohio, because it lacks heat and drought tolerance. Perennial ryegrass produces palatable forage with high nutritive value. It has a long growing season and yields well under good fertility when moisture is adequate. It is a vigorous establisher and is often used in mixtures to establish quick ground cover. Because it is less winter hardy than other grasses, perennial ryegrass is best seeded in combination with other grasses and legumes. Perennial ryegrass can be grown on occasionally wet soils. Compared with orchardgrass, it is lower yielding, less competitive with legumes, and later to mature. Like orchardgrass, perennial ryegrass can withstand frequent cutting or grazing. It is difficult to cut with a sickle bar mower and is slower to dry than other grasses, so it is better suited to grazing, greenchopping, and silage harvesting than for dry hay.

Perennial ryegrass varieties can differ markedly in winter hardiness and recovery from winter injury. For permanent pastures, select varieties that are proven to persist under Ohio conditions. Maturity also differs widely among ryegrass varieties. Be sure to purchase endophyte-free seed of forage-type varieties; seed of many turf-type varieties is infected with endophyte (a fungus inside the seed and the plant), which can produce compounds harmful to livestock and cause a neurological condition known as ryegrass staggers. Forage-type varieties are either diploid (the basic chromosome number is doubled) or tetraploid (basic chromosome number is quadrupled). Tetraploid varieties have fewer, but larger, tillers and wider leaves, resulting in more open sods than diploids. Tetraploids are usually slightly higher in forage digestibility.

Hybrid ryegrass (Lolium hybridum) is achieved by crossing perennial and annual ryegrass. It generally has characteristics intermediate between those of perennial and annual ryegrass. For example, hybrid ryegrass has lower winter hardiness than perennial ryegrass but should persist longer than annual ryegrass.

Annual ryegrass (Lolium multiflorum Lam.), also known as Italian ryegrass, is generally annual or biennial in longevity, and can provide short-term high yields of high-quality forage. Italian ryegrass varieties differ markedly in maturity and growth habit. Some are true annuals (referred to as Westerwold types) that are early maturing, head out in every growth cycle, and complete their life cycle by late summer when planted in the spring. Other varieties (referred to as Italian-types) are very late to mature and head out little at all the first year and may survive through the winter to produce forage the second year.

Reed Canarygrass (Phalaris arundinacea L.)

Reed canarygrass is a tall, leafy, coarse, high-yielding perennial grass tolerant of a wide range of soil and climatic conditions (Table 7-1 and 7-2). It can be used for hay, silage, and pasture. It has a reputation for poor palatability and low forage quality. This reputation was warranted in the past because older varieties produced forage containing alkaloid compounds (bitter, complex, nitrogen-containing compounds). However, varieties are now available that make this species an acceptable animal feed, even for lactating dairy cows.

Reed canarygrass grows well in very poorly drained soils but is also productive on well-drained upland soils. It is winter hardy, drought tolerant (deep-rooted), resistant to leaf diseases, and persistent. It responds to high fertility and tolerates spring flooding, low pH, and frequent cutting or grazing. Reed canarygrass forms a dense sod. Limitations of this grass include slow establishment, expensive seed, and rapid decline in forage quality after heading.

Only low-alkaloid varieties (e.g., Palaton, Venture, Rival) are recommended if the crop is to be used as an animal feed. These varieties are palatable and equal in quality to other cool-season grasses when harvested at similar stages of maturity. Common reed canarygrass seed should be considered to contain high levels of alkaloids and is undesirable for animal feed.

Smooth Bromegrass (Bromus inermis Leyss.)

Smooth bromegrass is a leafy, sod-forming perennial grass best suited for hay, silage, and early spring pasture. It spreads by underground rhizomes and through seed dispersal. Smooth bromegrass is best adapted to well-drained silt-loam or clay-loam soils. It is a good companion with cool-season legumes. Smooth bromegrass matures somewhat later than orchardgrass in the spring and makes less summer growth than orchardgrass. It is very winter hardy and, because of its deep root system, will survive periods of drought.

Smooth bromegrass produces excellent quality forage, especially if harvested in the early heading stage. It is adversely affected by cutting or grazing when the stems are elongating rapidly (jointing stage) and is less tolerant of frequent cutting. It should be harvested for hay in the early heading stage for best recovery growth. Fluffy seed makes this grass difficult to drill unless mixed with a carrier (e.g., oats, rice hulls, vermiculite, small amount of phosphate fertilizer). It is susceptible to leaf diseases.

Improved high-yielding and persistent varieties are available. Some varieties are more resistant to brown leaf spot. These improved varieties start growing earlier in the spring and stay green longer than common bromegrass, which has uncertain genetic makeup.

Tall Fescue (Festuca arundinacea Schreb.)

Tall fescue is a deep-rooted, long-lived, sod-forming grass that spreads by short rhizomes. It is suitable for hay, silage, or pasture. Tall fescue is the best cool-season grass for stockpiled pasture or field-stored hay for winter feeding. It is widely adapted and persists on acidic, wet soils of shale origin. Tall fescue is drought resistant and survives under low fertility conditions and abusive management. It is ideal for waterways, ditch and pond banks, farm lots, and lanes. It is the best grass for areas of heavy livestock and machinery traffic.

Most of the tall fescue in older permanent pastures in Ohio contains a fungus (endophyte) growing inside the plant. The fungal endophyte produces alkaloid compounds that reduce palatability in the summer and result in poor animal performance. Several health problems may develop in animals grazing endophyte-infected tall fescue, especially breeding animals. Deep-rooted legumes should be included with tall fescue if it is to be used in the summer. Legumes improve animal performance, increase forage production during the summer, and dilute the toxic effect of the endophyte when it is present. For more information on this problem and solutions, refer to fact sheets available through county Extension offices and online at: www.ohioline.osu.edu .

Newer endophyte-free varieties or varieties with very low endophyte levels (less than 5%) are recommended if stands are to be used for animal feed. In addition, varieties are available with non-toxic endophytes that do not produce harmful alkaloids. Kentucky-31 is the most widely grown variety, but most seed sources of this variety are highly infected with the toxic endophyte fungus and should not be planted for livestock feed. When buying seed, make sure the tag states that the seed is endophyte-free or has a very low percentage of infected seed, or contains non-toxic endophyte only. Because endophyte-free varieties are less stress tolerant than endophyte-infected varieties, they should be managed more carefully.

Timothy (Phleum pratense L.)

Timothy is a hardy perennial bunchgrass that grows best in cool climates. It generally grows better in northern Ohio than southern Ohio. Its shallow root system makes it unsuitable for droughty soils. It produces most of its annual yield in the first crop. Summer regrowth is often limited because of timothy’s intolerance to hot and dry conditions. Timothy is used primarily for hay and is especially popular for horses. It requires fairly well-drained soils. Timothy is less competitive with legumes than most other cool-season grasses. It is adversely affected by cutting or grazing when the stems are elongating rapidly (jointing stage) and is less tolerant of frequent cutting. It should be harvested for hay in the early heading stage for best recovery growth.

Chicory (Cichorium intybus L.)

Forage chicory is relatively new to Ohio. It is a perennial forb that is best utilized for rotational grazing. Chicory requires well-drained to moderately drained soils, medium to high fertility, and a pH of 5.5 or greater. It produces leafy growth with higher nutritive value and higher mineral content than alfalfa or cool-season grasses. Its deep taproot provides drought tolerance and good growth from spring through the summer slump period of cool-season grasses. Animal performance on forage chicory has been exceptional. An important management consideration is to prevent bolting of stems in the spring. Stubble heights greater than 1.5 inches or a rest period longer than 25 days can allow stems to bolt (a period of rapid stem growth). The thick taproot of chicory can be exposed and damaged by overgrazing, excessive hoof traffic, and frost heaving. Chicory requires nitrogen fertilization rates similar to those used for cool-season grasses.

‘Puna’ was the first variety to be sold in the United States. Other forage chicory varieties are now available from various seed companies.

Sweetclover (Melilotus species)

The cultivated sweetclovers, both yellow (Melilotus officinalis Lam.) and white-flowered types (Melilotus alba Medik.), are not perennial species, but typically biennial. They are excellent for soil improvement and as nectar-producing plants for honey bees. Sweetclover is not generally grown for forage but has been used for pasture and even hay or silage. The plant contains coumarin, which reduces palatability to livestock. Coumarin also can be converted to dicoumarol during heating and spoilage of hay or silage, which reduces blood-clotting ability and can result in livestock death. Low coumarin varieties have been developed. Sweetclover requires well-drained soils with near neutral pH (6.5 or higher). It is drought tolerant and winterhardy.

Forage Species Identification

Several excellent printed and online resources are available for identifying forage species. Here is a partial list:

Printed publications

Identifying Pasture Grasses, University of Wisconsin, Bulletin A3637

Identifying Pasture Legumes, University of Wisconsin, Bulletin A3787

Forage Identification and Use Guide, University of Kentucky, Cooperative Extension Service, Bulletin AGR-175

Forage Legumes, 2nd Ed., University of Minnesota, Station Bulletin 608-2003

Forage Field Guide, Purdue University, Extension Guide ID-317

Online resources:

Ohio State University Forage Images, hcs.osu.edu/hcs412/forageID.htm

Purdue Forage Identification pages, www.agry.purdue.edu/ext/forages/forageid.htm

Oklahoma Forages, forage.okstate.edu/index.htm

Pre-Establishment Fertilization and Liming

Soil pH

Proper soil pH and fertility are essential for optimum economic forage production. Take a soil test to determine soil pH and nutrient status at least six months before seeding. This allows time to correct deficiencies in the topsoil zone. The topsoil in fields with acidic subsoils (most common in eastern Ohio) should be maintained at higher pH than the topsoil in fields with neutral or alkaline subsoils.

Topsoil pH Levels for Forages

• pH 6.8 for alfalfa on mineral soils with subsoil pH less than 6.0
• pH 6.5 for other forage legumes and grasses on mineral soils with subsoil pH less than 6.0
• pH 6.5 for alfalfa on mineral soils with subsoil pH greater than 6.0
• pH 6.0 for other forage legumes and grasses on mineral soils with subsoil pH greater than 6.0

Soil pH should be corrected by application of lime when topsoil pH falls 0.2 to 0.3 pH units below the recommended levels. With conventional tillage plantings, soil samples should be taken to an eight-inch depth, and lime should be incorporated and mixed well in the soil at least six months before seeding. If more than four tons per acre of lime are required, half the amount should be incorporated deeply and the other half incorporated lightly into the top two inches. If low rates of lime are recommended or if a split application is not possible, the lime should be worked into the surface rather than plowed down. This assures a proper pH in the surface soil where seedling roots develop and where nodulation begins in legumes.

Phosphorus and Potassium

Corrective applications of phosphorus and potassium should be applied prior to seeding, regardless of the seeding method used; however, fertilizer applications incorporated ahead of seeding are more efficient than similar rates not incorporated. This is especially true for phosphorus. Phosphorus and potassium fertilizer recommendations for forages are provided in Tables 7-5 to 7-7.

Pre-Establishment Fertilization for No-Till

For no-till seedings, take soil samples to a four-inch depth to determine pH and lime needs, and to a normal eight-inch depth to determine phosphorus and potassium needs. If possible, make corrective applications of lime, phosphorus, and potassium earlier in the crop rotation when tillage can be used to incorporate and thoroughly mix these nutrients throughout the soil. When this is not feasible, be sure to make lime, phosphorus, and potassium applications at least eight months or more ahead of seeding to obtain the desired soil test levels in the upper rooting zone. Use the finest grade of lime available at a reasonable price when surface applications are made.

Lime and phosphorus move slowly through the soil profile. Once soil pH, phosphorus, and potassium are at optimum levels, surface applications of lime and fertilizers maintain these levels. Attempts to establish productive forages often fail where pH, phosphorus, or potassium soil-test values are below recommended levels, even when corrective applications of these nutrients are surface applied or partially incorporated just before seeding.

Starter Nitrogen

Seedling vigor of cool-season forage grasses is enhanced on many Ohio soils by nitrogen applied at seeding time. Apply nitrogen at 10 to 20 lbs per acre when seeding grass-legume mixtures, and 30 lbs per acre when seeding pure grass stands. Starter nitrogen applications of 10 lbs per acre may be beneficial with pure legume seedings, especially under cool conditions and on soils low in nitrogen. Manure applications incorporated ahead of seeding can also be beneficial to seedling establishment of forages, including alfalfa. Obtain a manure nutrient analysis and base application rates on soil-test results. For more information on manure application to soils, refer to the Ohio Livestock Manure Management Guide, Ohio State University Extension Bulletin 604.

Stand Establishment

Establishing a good stand is critical for profitable forage production and requires attention to details for success. As discussed previously, begin by selecting species adapted to soils where they will be grown. Plan well ahead of time so corrective lime applications have time to neutralize soil acidity, and soil fertility deficiencies can be corrected. Make sure fields are free of any herbicide carryover that can harm forage seedlings. Refer to the current Weed Control Guide (Bulletin 789) and current labels for more information on herbicides with crop rotation restrictions.

About 20 to 25 seedling plants per square foot in the seeding year usually results in good stands the following year. Once established, a stand having about six grass and/or legume plants per square foot is generally adequate for good yields. The guidelines presented here greatly improve the likelihood of successful establishment of productive forage stands.

Crop Rotation and Autotoxicity

Crop rotation is an important management tool for improving forage productivity, especially when seeding forage legumes. Crop rotation reduces disease and insect problems. Seeding alfalfa after alfalfa is especially risky because old stands of alfalfa release a toxin that reduces germination and growth of new alfalfa seedlings (called autotoxicity). This is especially true on heavy-textured soils. Disease pathogens accumulate and can cause stand establishment failures when seeding into a field that was not rotated out of alfalfa. Rotating to another crop for at least one year before re-establishing a new alfalfa stand is the best practice. If that is not possible, chemically kill the old alfalfa in the fall and seed the next spring, or spring kill and seed in late summer.

Seed Quality

High-quality seed of adapted species and varieties should be used. Seed lots should be free of weed seed and other crop seed, and contain only minimal amounts of inert matter. Certified seed is the best assurance of securing high-quality seed of the variety of choice. Purchased seed accounts for just 20% or less of the total cost of stand establishment. Buying cheap seed and seed of older varieties is a false and short-lived economy. Always compare seed price on the basis of cost per pound of pure live seed, calculated as follows:

• percent purity = 100% – ( percent inert matter + percent other crop seed + percent weed seed)
• percent pure live seed (PLS) = percent germination x percent purity
• lbs of PLS = lbs of bulk seed x percent PLS

Seed Inoculation

Legume seed must be inoculated with the proper nitrogen-fixing bacteria prior to seeding to assure good nodulation. Inoculation is especially important when seeding legumes in soils where they have not been grown for several years. Because not all legume species are colonized by the same strains of nitrogen-fixing bacteria, be sure to purchase the proper type of inoculum for the forage legume to be planted. Verify the inoculant expiration date and make sure it was stored in a cool, dry place. Because many seed suppliers distribute pre-inoculated seed, check the expiration date and reinoculate if necessary. If in doubt, reinoculate the seed before planting. The seed should be slightly damp and sticky before adding the inoculant. This can be accomplished with a syrup/water mixture or a commercial sticker solution. Soft drinks are also effective as sticking agents. Protect inoculants and inoculated seed from sun and heat as much as possible and plant soon after inoculation.

Seed Treatments

Fungicide-treated seed is highly recommended for alfalfa and may be useful for red clover. Apron (metalaxyl) and Apron XL (mefanoxam) are systemic fungicides for controlling seedling damping-off diseases caused by Pythium and Phytophthora during the first four weeks after seeding. These pathogens kill legume seedlings and cause establishment problems in wet soils. Many companies are marketing alfalfa seed treated with either Apron or Apron XL. Various other seed treatments and coatings are sometimes added to forage seed. Always consider the cost vs. the opportunities for benefit.

It is very important to calibrate seeders appropriately. For example, lime coatings can account for up to one-third of the weight of the seed, so the actual number of seeds planted can be drastically affected when seeding on a weight basis. In addition, some seed coatings affect the flowability of seed, which can dramatically affect the seeding rate output of a planter. The manufacturers’ seeding calibrations are likely to not hold true for coated seed.

Spring Seedings

Plant as soon as the seedbed can be prepared after March 15 in southern Ohio and April 1 in northern Ohio (Table 7-8). In most years, spring seeding should be completed by early May in northern Ohio and by late April in southern Ohio. With early seeding, the plants become well established before the warm and dry summer months. Weed pressure increases with delayed seeding. Annual grassy weeds can be especially troublesome with delayed spring seedings. Herbicides are usually essential when seeding late in the spring. Refer to Chapter 12 (Weed Management) for principles and guidelines of weed management in forages. For specific herbicide recommendations, refer to the Weed Control Guide for Ohio Field Crops (Bulletin 789).

Direct seeding without a companion crop in the spring allows growers to harvest two or three crops of high-quality forage in the seeding year, particularly when seeding alfalfa and red clover. Select fields with little erosion potential when direct seeding into a tilled seedbed. Weed control is important during early establishment when direct seeding pure legume stands. Several preplant and post-emergent herbicide options are available for pure legume seedings (refer to the Weed Control Guide for Ohio Field Crops, Bulletin 789).

Small grain companion crop seedings are successful when managed properly. Companion crops reduce erosion in conventional seedings and help minimize weed competition. Companion crops usually increase total forage tonnage in the seeding year, but forage quality will be lower than direct seeded legumes. When seeding with a small grain companion crop, take precautions to reduce excessive competition, which may lead to establishment failures:

• Spring oats and triticale are the least competitive, while fall-planted winter cereals are often too competitive.
• Use early-maturing, short, and stiff-strawed small grain varieties.
• Sow companion small grains at 1.5 to 2.0 bushels per acre.
• Remove small grain companions as early pasture or silage.
• Do not apply additional nitrogen for the companion crop.

Where the need for erosion control suggests use of a companion crop, but high-quality legume forage is desired the first year, seed oats as a companion and kill it at four to eight inches with a post-emergent grass herbicide. The oats will suppress early weed growth, provide erosion protection, and protect seedlings from wind damage. After oats are killed, the legume forage will perform about the same as in a direct seeding.

Late Summer Seedings

Late summer is an excellent time to establish many forage species, provided sufficient soil moisture is available. August is the preferred time for late summer seeding because it allows enough time for plant establishment before winter. Do not use a companion crop with August seedings because it will compete for soil moisture and can slow forage seedling growth to the point where the stand will not become established well enough to survive the winter. Refer to Chapter 12 (Weed Management) for weed control guidelines for late summer forage seedings.

Sclerotinia crown and stem rot is a serious disease threat when seeding alfalfa and clovers in late summer. The risk of infection is greatest in fields where forage legumes have been grown recently and minimum tillage is used. Sclerotinia infects seedlings in the fall, but injury is not visible until plants begin to die in late winter and early spring. Crop rotation, conventional tillage plantings, and seeding by early August reduce the risk of severe damage from this disease. A limited number of alfalfa varieties have some resistance to this disease. For more information on this disease, refer to Bulletin 827, Corn, Soybean, Wheat, and Alfalfa Field Guide.

Conventional Tillage Seeding

The ideal seedbed for conventional seedings is smooth, firm, and weed-free. Don’t overwork the soil. Too much tillage depletes moisture and increases the risk of surface crusting. Firm the seedbed before seeding to ensure good seed-soil contact and reduce the rate of drying in the seed zone. Cultipackers and cultimulchers are excellent implements for firming the soil. The lack of a firm seedbed is a major cause of establishment failures. The soil should be firm enough at planting so that a footprint is no deeper than ½ to ¾ inch.

Seeding depth for most cool-season forages is ¼ to ½ inch on clay and loam soils. On sandy soils, seed can be placed ½ to ¾ inch deep. Seeding too deep is one of the most common reasons for seeding failures.

Seeding equipment. Forage stands can be established with many different types of drills and seeders, provided they are adjusted to plant seed at an accurate depth and in firm contact with the soil. When seeding into a tilled seedbed, drills with press wheels are an excellent choice. If the seeder is not equipped with press wheels, cultipack before and after seeding in the same direction as the seeder was driven. This assures that seed is covered and in firm contact with the soil. Cultipacker seeders, such as the Brillion seeder, provide accurate and consistent seed placement in tilled seedbeds.

Fluid seeding can be used to seed forage legumes. Seed is distributed in a carrier of water or in a fertilizer solution. Custom application is recommended because it requires special equipment for good seed suspension and distribution. Prepare a firm seedbed and cultipack after the seed is “sprayed” on. For fluid seeding, seed should be mixed into solution at the field and applied immediately. Some producers are also having success with seeding legumes through dry fertilizer air spreaders, with cultipacking before and after the seed is broadcast.

No-Till and Minimum-Till Seeding

Many producers are successfully adopting minimum and no-tillage practices for establishing forage crops. Advantages include soil conservation, reduced moisture loss, lower fuel and labor requirements, and seeding on a firm seedbed. All forage species can be seeded no-till. Species such as red clover, which have good seedling vigor, are the easiest to establish. No-till forage seedings are most successful on silt loam soils with good drainage. Consistent results are more difficult on clay soils or poorly drained soils. Weed control and sod suppression is essential for successful no-till establishment, because most forage crops are not competitive in the seedling stage.

Seed placement is critical with reduced tillage. It is very easy to plant seeds too deep with no-till drills. A relatively level seedbed improves seed placement. A light disking may be necessary before attempting to seed. Plant seed shallow (¼ to ½ inch, in most cases) in firm contact with the soil. Crop residue must be managed to obtain good seed-soil contact. Chisel plowing or disking usually chops residue finely enough for conventional drills to be effective. When residue levels are greater than 35%, no-till drills are recommended.

For no-till planting following corn, plant as soon as the soil surface is dry enough for good soil flow around the drill openers and good closure of the furrow. Perennial weeds should be eradicated in the previous corn crop. If perennial weeds are still present, apply glyphosate before seeding. If any grassy weeds or winter annual broadleaf weeds are present in the field, use paraquat or glyphosate before seeding. Most drills can handle corn grain residue, but removal of some of the residue (e.g., for bedding) often increases the uniformity of stand establishment. Most drills do not perform as well when corn stalks are chopped and left on the soil surface. Be sure to avoid problems with carryover of triazine residue from the previous corn crop.

No-till planting following small grains is a good way to conserve valuable moisture. Weeds should be effectively controlled in the small grain crop. Ideally, wait to plant the forage crop until at least ½ inch of rain has fallen postharvest to stimulate germination of volunteer small-grain seeds and weeds; however, do not delay planting beyond the recommended seeding date for your area. Burn down any weeds and volunteer small grain seedlings before seeding the forage crop. Glyphosate can be used if thistles, Johnsongrass, or other perennial or biennial weeds are present in the small grain stubble. Remove straw after small grain harvest. It is not necessary to clip and remove stubble; however, it may be removed if additional straw is desired. Do not clip stubble and leave it in the field, as it may interfere with seed-soil contact when seeding forages. If volunteer small grains become a problem after seeding, apply a selective grass herbicide to pure legume seedings to remove excessive competition.

Insect control can be a serious problem in no-till seedings, especially those seeded into old sods. Slugs can be especially troublesome where excessive residue is present from heavy rates of manure applied in previous years. Chemical control measures for slugs are limited to a methaldehyde bait (Deadline bullets). Lorsban-4E insecticide is registered for use during alfalfa establishment for suppression of cutworms, wireworms, and grubs.

Seeding-Year Harvest Management

Harvest management of cool-season forages during the seeding year depends on time and method of seeding, species, fertility, weather conditions, and other factors. Forages seeded in August or early September should not be harvested or clipped until the following year. For spring seedings, it is best to mechanically harvest the first growth. This is especially true for tall-growing legumes. If stands are grazed, stock fields with enough livestock to consume the available forage in less than seven days. Grazing for a longer period increases the risk of stand loss. Soils should be firm to avoid trampling damage. General harvest management guidelines for spring seedings, according to species, are presented here.

Alfalfa—Generally two harvests are possible in the seeding year when alfalfa is seeded without a companion crop; three harvests are possible with early planting and good growing conditions. The first cutting can be made 60 to 70 days after emergence. Subsequent cuttings should be made in early bloom stage, with the last harvest taken by the first week of September. Fall cutting is not advisable; even a late dormant cutting is not recommended because it increases the risk of winter heaving. When seeding with a small grain companion crop, the first harvest should be taken during the late boot or early-heading stage of the companion crop.

Birdsfoot Trefoil—Seedling growth of trefoil is much slower than alfalfa or red clover. Seeding year harvests should be delayed until the trefoil is in full bloom. Do not harvest after September 1. When seeded with a companion crop, an additional harvest after removal of the small grain is generally not advisable.

Red Clover—When seeded without a companion crop, red clover can usually be harvested twice in the year of establishment. Under good conditions, up to three harvests are possible. Harvest red clover before full bloom in the seeding year. If allowed to reach full bloom in the year of seeding, red clover often has reduced stands and yields the following year. Complete the last harvest by the first week of September.

Cool-Season Grasses—Harvest management depends greatly on stand vigor and weather conditions. Most grasses establish slowly compared with alfalfa. Clipping may be necessary to prevent annual weeds from going to seed. Early clipping at 6 to 8 inches of grass growth will also promote tillering of the seedlings.

Fertilizing Established Stands

A current soil test is the best guide for a sound fertilization program. Forages are very responsive to good fertility. Adequate levels of phosphorus and potassium are important for high productivity and persistence of legumes, especially alfalfa. Forage fertilization should be based on soil-test levels and realistic yield goals. Under hayland management, forages usually need to be topdressed annually to maintain soil nutrient levels and achieve top production potential.

Each ton of tall grass or legume forage removes approximately 13 pounds of P2O5 and 50 pounds of K2O. These nutrients need to be replaced, preferably in the ratio of one part phosphate to four parts potassium. Phosphorus and potassium recommendations for forages are given in Tables 7-5 to 7-7.

Timing Topdress Applications

The timing of phosphorus and potassium applications is not critical when soil-test levels are optimum. Avoid applications with heavy equipment when the soil is not firm. Soil conditions are frequently most conducive to fertilizer applications immediately following the first cutting or in late summer and early fall. Split applications, one-half after the first cutting and one-half in late summer or early fall, may result in more efficient use of fertilizer nutrients when high rates of fertilizer are recommended. If soil-test levels are marginal to low, fall fertilization is especially important to provide nutrients such as potassium that are important for winter survival.

Nitrogen Fertilization

Where grasses are the sole or predominant forage, nitrogen fertilization is extremely important for good production. Economic returns are usually obtained with 150 to 175 pounds of nitrogen per acre per year split three times during the year—70 to 80 pounds per acre in early spring when grasses first green up and 50 pounds per acre after each cutting except after the last cutting of the season.

Legumes fix atmospheric nitrogen. Where the forage stand is more than 35% legumes, nitrogen should not be applied (Table 7-9). In pastures, nitrogen application can be used strategically, so increased forage production occurs only when it will be most needed. This is discussed in more detail in Chapter 9, Pasture and Grazing Management.

When applying nitrogen in the summer, keep in mind that some forms are subject to surface volatilization, resulting in loss of available nitrogen. Ammonium nitrate is the best source because surface volatilization losses are minimized; however, this formulation is now difficult to purchase. For more information on nitrogen forms and volatilization losses, refer to Agronomy Fact Sheet AGF-205 or Extension Bulletin E-2567, Tri-State Fertilizer Recommendations for Corn, Soybeans, Wheat and Alfalfa, available at county offices of OSU Extension.

Micronutrients

Micronutrient deficiencies are rare in most Ohio mineral soils. Micronutrient fertilization should be based on demonstrated need through soil testing and/or tissue testing. Boron may be needed when alfalfa and clover are grown on sandy soils and highly weathered soils low in organic matter. If the soil test is one part per million (ppm) or less of boron (B), or a plant tissue test shows 30 ppm or less B, then apply a fertilizer containing two pounds of B per acre. Sulfur may be needed when alfalfa and clover are grown on low organic matter soils and coarse soils when yield levels are high. Use a sulfate form of sulfur if the application is made in the spring, and an elemental form of sulfur for fall applications. Refer to Extension Bulletin E-2567, Tri-State Fertilizer Recommendations for Corn, Soybeans, Wheat and Alfalfa, for more details on micronutrient fertilization.

Grass Tetany

Grass tetany occurs in animals when their demands for magnesium exceed the supply. It most often occurs in the spring when high-producing animals are consuming primarily grass forage. High soil potassium tends to reduce uptake of magnesium by plants. The risk of grass tetany is reduced by not applying potash in early spring to grasses, because grasses take up more potassium than needed for growth (luxury consumption), and potassium uptake is favored by plentiful soil moisture. After the first harvest, apply needed fertilizer to maintain a balanced soil-fertility program. It may also be helpful to feed livestock a high-magnesium supplement during spring.

Established Stand Harvest Management

Harvest management is an important tool in achieving high-quality forage, high yields, and stand persistence. Harvest management can also be used to reduce the impact of weeds, insects, and disease pests. Harvest timing is a compromise between forage yield, quality, and persistence. While forage quality decreases with maturity, dry matter yield usually increases up to full-flower stage in legumes and full-heading stage in grasses. Cutting more frequently at earlier stages of maturity results in forage with higher nutritive value but lower yield compared with cutting less frequently at more mature stages of growth.

A good compromise between forage yield, quality, and stand persistence is to harvest legumes in late-bud to early-bloom stage, and grasses in late-boot to early-heading stage. Harvesting at this stage results in the highest yields of digestible dry matter per acre. Cutting management of grass-legume mixtures should be based on the best harvest schedule for the legume.

First Harvest Timing

Make a timely first harvest to achieve the best quality possible in what is usually the largest crop of the year. Forage quality declines more rapidly with advancing maturity in the spring than it does later in the summer. Timing of the first harvest should be based on the calendar rather than on stage of maturity. Bud development and flowering are not reliable guides for proper timing of first cutting in Ohio. In some years, little or no bloom is present in the spring; in others, bloom is abundant.

Table 7-10 gives recommended harvest dates for the first cutting of legume-grass hay meadows. Harvesting during these periods maximizes yields of digestible dry matter per acre. By using various grasses and legumes that differ in maturity development (Table 7-2), producers can spread the optimum first cutting date over one week to 10 days.

Most grasses should be harvested in the boot stage for best forage quality; however, timothy and smooth bromegrass should not be cut until the grass is in the early heading stage. Earlier harvesting of these species may reduce regrowth and cause stand loss, because the basal buds for regrowth are not fully developed until early heading.

Summer Harvest Timing

Stage of growth is usually a reliable guide for timing summer harvests of legumes. Generally, summer cuttings are permitted to reach early bloom for alfalfa (approximately 35 days between cuttings) and half bloom for birdsfoot trefoil and red clover. High yields of good-quality forage can be harvested if three or more cuttings are made on a 35- to 40-day schedule. Four cuttings of alfalfa can be made on soils with good fertility without any detrimental effects on the stand. Harvest schedules for legume-grass mixtures should follow closely to what favors the legume component. Smooth bromegrass and timothy are more compatible with less intensively managed stands (three-cut schedule), while orchardgrass, perennial ryegrass, tall fescue, and reed canarygrass are adaptable to more frequent harvesting.

Intensive Cutting for High Quality

More intensive frequent cutting schedules are desirable where high forage quality is important. Shorter harvest intervals will usually shorten stand life. Allowing legume stands to reach early flower stage once during the season improves stand persistence. This can usually be achieved in late summer without great reductions in forage quality (forage fiber levels increase at a slower rate in late summer than in spring and early summer). Cutting intervals that are consistently shorter than 30 days stress legume stands because the plants do not fully replenish depleted energy reserves in the taproots and crowns. Fiber levels may be undesirably low when legumes are cut extremely early (pre-bud to very early bud stage).

Some grass species can be harvested very intensively to achieve dairy-quality forage. Pure stands of orchardgrass and perennial ryegrass (where adapted) can be maintained on harvest intervals of 24 to 28 days under good fertility management.

Fall Harvesting

Producers often want to harvest the fall growth from forage stands, but fall harvesting usually increases the risk of legume heaving and winter kill, and interferes with accumulation of root reserves required for winter survival and growth the following spring. The need for the forage or its value should be weighed against the increased risk of stand damage.

Minimizing Fall Harvesting Hazard to Tall Legumes

• Complete the last regular harvest by the following dates—September 7 in northern Ohio, September 12 in central Ohio, and September 15 in southern Ohio.
• Do not harvest during late September and October. Forages are actively storing reserve carbohydrates in the crowns and roots during this period.
• If a late fall harvest is made, it should be delayed until after a killing frost (25°F for several hours). A word of caution—removing topgrowth at this time can dramatically increase the risk of legume frost heaving on heavy soils. Mulching with up to four tons per acre of straw-manure or two tons per acre of old hay or straw should reduce frost-heaving potential after a late harvest.
• Late fall harvesting should only be attempted on healthy, established stands grown on well-drained soils with optimum pH and high fertility (high soil potassium levels are especially important).
• Avoid fall harvesting of new seedings.
• If a mid-fall harvest is made, select fields that are well drained, have optimum pH and fertility, are planted to improved varieties having multiple pest resistance, and where at least 45 days of regrowth was allowed prior to the fall harvest.

Weed Management in Forages

Refer to Chapter 12, Weed Management, for principles and guidelines of weed management in forages. For specific herbicide recommendations, refer to the Weed Control Guide for Ohio Field Crops, Bulletin 789.

Insect Pest Management

Management of forage insect pests is important to achieve high yields of high-quality forage. The primary insect problems in Ohio are the alfalfa weevil and the potato leafhopper in alfalfa. The alfalfa weevil is primarily active in the spring. The potato leafhopper is active during the summer months and can cause severe yield and quality losses in alfalfa. New alfalfa seedings are especially vulnerable to potato leafhopper damage.

Potato leafhopper resistant alfalfa varieties offer an excellent tool for managing this insect pest in Ohio. For yield performance data of leafhopper resistant varieties in Ohio, refer to the Ohio Forage Performance Trials reports available online at: www.ag.ohio-state.edu/~perf/ or at county Extension offices.

When pest populations reach or exceed action thresholds, it is economically justifiable to either harvest the crop, provided it is near the harvestable stage, or chemically treat the stand to control the pest in question. Producers should scout fields and determine if the action threshold has been exceeded. For more specific guidelines on scouting and management of alfalfa insect pests, refer to these fact sheets, available online or at Extension offices:

• Insect Pest Management on Alfalfa, FC-ENT-0031, online at: ohioline.osu.edu/ent-fact/0031.html
• Alfalfa Weevil, FC-ENT-0032, online at: ohioline.osu.edu/ent-fact/0032.html
• Potato Leafhopper on Alfalfa, FC-ENT-0033, online at: ohioline.osu.edu/ent-fact/0033.html
• Meadow Spittlebug on Alfalfa, Field Crops Pest Management Circular No. 34, online at: ohioline.osu.edu/icm-fact/fc-34.html

Warm-Season Forages

Annual Lespedeza (Kummerowia spp.)

Annual lespedezas are spring-sown, warm-season legumes adapted to the southern third of Ohio. They can be used for hay, pasture, and soil erosion control. These species are relatively low yielding, but produce non-bloating forage of high nutritive value for late summer grazing. They can be grown on acidic and low phosphorus soils; however, they will respond to both lime and phosphorus fertilization. Annual lespedezas grow best on well-drained soils. They are dependable reseeders and can persist in pastures if allowed to reseed each year. Annual lespedeza can be used effectively in pasture renovation to improve animal performance and late-summer forage production, especially in endophyte-infected tall fescue pastures. Seed should be inoculated with the proper Rhizobia the first time it is planted in a new area.

Perennial Warm-Season Grasses

Perennial warm-season grasses have potential to produce hay and pasture growth during the warm and dry midsummer months. These grasses initiate growth in late April or early May and produce 65% to 75% of their growth from mid-June to mid-August in Ohio. Warm-season grasses complement cool-season grasses by providing forage when the cool-season grasses are less productive. Warm-season grasses produce well on soils with low moisture-holding capacity, low pH, and low phosphorous levels. However, they do best on deep, fertile, well-drained soils with good water-holding capacity.

Switchgrass (Panicum virgatum L.), Indiangrass (Sorghastrum nurans [L.] Nash), and big bluestem (Adropogon gerardii Vitman) are winter hardy and grow in all areas of Ohio. Eastern gamagrass (Tripsacum dactyloides L.) and Caucasian bluestem (Bothriochloa caucasia [Trin.] C. E. Hubb) have also been grown in Ohio. These grasses are very slow to establish and are weak competitors with weeds until established. Two years is generally required for successful establishment of warm-season grasses. Detailed information on these species and their establishment and management is available in Agronomy Facts AGF-022, Perennial Warm Season Grasses for Ohio.

Annual Forage Crops

Annual forage crops can be used effectively in a forage production system. These crops:

• Provide supplemental feed when perennial forages are less productive.
• Provide emergency feed when perennial crops fail.
• Serve as interim crops between grazing periods of perennial forages when long rest periods are needed.
• Extend the grazing season in the fall and early spring.

Most annual forage crops are best used for pasture or silage rather than for hay. Double-cropping combinations are feasible with these annual forage crops (for example, small grains followed by summer annual grasses or brassicas). Production of corn silage is covered in Chapter 4, Corn Production.

Small Grains for Forage

Spring oat (Avena sativa L.) is commonly used as a companion crop for seeding forage legumes. It can be used for silage or spring and early summer pasture when sown early. Oats grazed or chopped early regrow and provide a second period of grazing or greenchop. Highest yields are achieved with a single harvest in early heading to milk stage. Oats can be used for hay; however, as with the winter cereals, oats are coarse, slow to dry, and often produce dusty hay. Ohio producers have also successfully used oats for late fall grazing, by seeding it in August (after winter wheat) or following an early corn silage harvest. Oats have been successfully aerially seeded into standing corn in mid-August to provide high-protein forage as a supplement to the lower quality corn stover when grazed in late fall after corn grain harvest.

Winter barley (Hordeum vulgare L.) is not as winter hardy as other winter cereal grains and is more sensitive to poorly drained soils. It can tolerate moderate droughts but does not produce well under moist, hot conditions. Barley provides good quality forage for grazing in the fall if seeded early, but it should not be grazed as close or as late in the fall as wheat or rye. Barley makes good quality silage, but is less desirable for hay after heading because the heads have awns or slender bristlelike appendages on the spikelets.

Winter wheat (Triticum aestivum L.) provides highly digestible fall and spring pasture. Winter wheat can be sown later in the fall than barley because it is more winter hardy and able to withstand wetter soils than barley. Wheat produces more tonnage than barley and is of higher quality than rye. With careful fall or early-spring grazing, it can be subsequently harvested for grain, silage, or hay. Varieties of winter wheat used for grain may also be used for forage.

Winter rye (Secale cereale L.) is the most winter hardy of the small grains and the most productive for pasture. Forage-type varieties are available that have greater fall growth and extend the grazing season in late fall. Although best production is on fertile, well-drained soils of medium or heavy texture, it is more productive than other small grains on soils with low pH and fertility, high clay or sand content, or poor drainage. Winter rye matures the earliest of the small grains, making it the most difficult of the small grains to manage for high quality forage in the spring. Palatability and quality of rye are unacceptable if allowed to mature past the boot stage.

Triticale (Trticum x Secale) is a hybrid of wheat and rye. Varieties are available for fall or spring seeding. Fall-seeded winter triticale varieties can be used for late fall and early-spring pasture, as well as for silage or hay. Under good management, triticale produces well. High animal performance is possible when it is harvested at the right stage. Winter triticale should be managed similarly to wheat, but matures about five to 10 days after wheat.

Mixtures of small grains or small grains with annual legumes (e.g., field peas, soybean) can be used to achieve specific production objectives. For example, oats can be mixed with the winter grains to increase fall growth for grazing without sacrificing yield of the winter cereals the following spring. Small grain-annual legume mixtures are especially useful when harvested as silage. The seed cost of annual legumes is usually higher and should be weighed against the value of the harvested forage. Adding annual legumes, such as peas, improves forage quality and expands the harvest window for achieving good-quality forage. These mixtures do not yield as much as corn silage, but their production in the spring may fill an important niche in a forage system. Harvest timing should be based on the proper time for the small grain species in the mixture.

Establishment and Fertilization

Seed small grains for forage in the same way as for grain (see Chapter 6). When seeding small grains for fall pasture, plant in August to mid-September. If small grains are planted only for pasture use, use the seeding rates given in Table 7-4 and apply nitrogen at a rate of 50 to 70 lbs per acre at planting time.

Harvest Management

For the best compromise between yield and quality, harvest oats, barley, and wheat in the early heading stage. Although harvesting later (up to early milk stage) increases tonnage, quality declines rapidly. Triticale should be harvested in the late boot to early heading stage. Rye should be harvested in the boot stage to avoid palatability problems and large reductions in forage quality. Always use a mower conditioner to increase the drying rate of small grains.

Grazing Management

Fall and spring grazing of small grains should begin when sufficient growth is available to support livestock. Delayed planting dates and wet fields during the prime grazing season often make grazing of small grains difficult in Ohio. In the fall, graze only early-seeded small grains. Begin grazing winter cereals when six inches of growth is available and leave three inches of stubble after grazing. Heavy fall grazing can increase the risk of winterkill. Do not graze when the small winter grain is dormant or when the ground is frozen if subsequent spring growth and/or grain production is desired. In the spring, graze only when fields are firm. Heavy or late-spring grazing greatly reduces grain yields. Remove livestock from small grain fields to be harvested for grain as soon as the plants begin stem elongation (jointing stage).

Animal Health Concerns with Small Grains

Animal health hazards are not as common with the small grains as they are with the sorghum species grasses; however, the following precautions should be taken:

• Supplement lush spring pastures with high-magnesium mineral blocks or mineral-salt mixes to reduce the risk of grass tetany.
• When using seed treated with fungicides, observe harvest and grazing restrictions on the label.
• Remove lactating dairy animals from small grain pastures two hours before milking to reduce the problem of off-flavored milk.
• Split nitrogen applications to avoid nitrate poisoning.

Summer-Annual Grasses

These grasses grow rapidly in late spring and summer and, when managed properly, provide high-quality forage. They are well suited as supplemental forages during hot, dry periods when perennial cool-season forages are less productive. Because the need for extra forage usually becomes apparent after row crops have been planted in early spring, summer-annual grasses are a good double-crop option when planted after a small grain crop. They have the potential to produce forage yields of three tons of dry matter per acre within 45 to 50 days. With the exception of pearl millet, the summer-annual grasses are members of the sorghum family and have the potential for prussic acid poisoning (see Animal Health Concerns).

Sudangrass (Sorghum bicolor [L.] Moench.) is fine-stemmed, leafy, and grows three to eight feet tall. Sudangrass regrows following each harvest, until cool temperatures or lack of moisture inhibit growth. It is the preferred summer-annual grass for pasture and can be used for hay. Solid stands grow shorter than when seeded in rows. Sudangrass usually contains lower levels of prussic acid and is usually lower yielding than the other sorghum family grasses.

Sudangrass hybrids are generally slightly higher yielding and have slightly higher prussic acid levels than sudangrass at comparable stages of growth.

Sorghum-sudangrass hybrids are crosses of sorghum with sudangrass. They resemble sudangrass in growth habit, but are generally taller, have larger stems and leaves, and are higher yielding. This grass can become coarse and unpalatable if not properly utilized. It is not as well suited for hay production as sudangrass. Sorghum-sudangrass hybrids regrow following each harvest, barring restrictive environmental conditions.

New varieties with higher digestibility are available, known as brown midrib varieties. Those varieties have a characteristic brown discoloration on the main vein (midrib) of the leaves, which is a marker for the mutation for lower lignin content. The brown midrib varieties have been shown to have greater animal preference and animal performance (intake and gains) compared with the normal varieties.

Forage sorghum (Sorghum bicolor [L.] Moench.) grows six to 15 feet tall and has potential for high yields. It is utilized as a one-cut silage or greenchop crop. Forage sorghum produces silage containing more digestible energy than legume and cool-season grass silage. Making high-quality silage from forage sorghum is generally easier than from forage legumes because of the high levels of nonstructural carbohydrates, which enhance fermentation.

The high-energy, low-protein characteristics of forage sorghum silage make it a good supplement for high-protein forage legumes. Because the feeding value of forage sorghum silage is considered to be about 85% that of corn silage, corn silage is usually the preferred high-energy silage grown in Ohio. Forage sorghum has the potential, however, to grow better than corn on light-textured, shallow soils that tend to be droughty. Brown midrib varieties with higher digestibility are available, as described earlier for the sorghum-sudangrass hybrids.

Pearl millet (Pennisetum glaucum L.) is not in the sorghum family, and prussic acid is not produced in the plant. It tends to have smaller stems and is leafier than the sorghum grasses. Pearl millet regrows after each harvest, but not as rapidly as sudangrass or sorghum-sudangrass hybrids. Its regrowth may also be more sensitive to cutting height than sudangrass. Other types of millets include German, Foxtail, and Japanese millet. German and Foxtail millet do not regrow after harvest. Japanese millet grows best in wet soils.

Summer-annual grass-legume mixtures are marketed by some seed dealers. The legumes (e.g., field pea, soybean) generally improve protein content compared with summer-annual grasses grown alone. The annual legumes included in these mixtures would be present in the first growth only; regrowth would occur only from the grasses. The additional cost of the legume seed should be weighed against the improved forage quality potential.

Establishment

Summer-annual grasses require well-drained to moderately well-drained soils. They grow best in warm weather and should be planted from about two weeks after corn planting until the end of June in northern Ohio and mid-July in southern Ohio. Soil temperatures should be at least 60°F to 65°F. Late plantings (after mid-July) shorten the growing season and may result in low yields because of poor establishment in dry soils in the summer followed by cool fall temperatures. Making two seedings about three weeks apart staggers the maturities and makes rotational grazing or harvest timing easier to manage.

Seeds should be planted ½ to one-inch deep on a well-prepared, firm, and moist seedbed. The seed can be broadcast and harrowed, lightly disked, or seeded with a grain drill. Forage sorghums should be planted in rows with row-crop planters to facilitate harvest and minimize lodging. These summer-annual grasses may also be established in grass sods or stubble with no-till equipment, but this is less desirable than conventional seedbed preparation. Refer to Table 7-4 for suggested seeding rates.

Fertilization

Determine lime and fertilizer needs by soil test. Fertilization is similar to that used to grow 100- to 150-bushels-per-acre corn. Incorporate fertilizer in the soil prior to seeding or apply at least six months before for no-till seedings. The soil pH should be maintained between 6.0 and 6.5 for best results.

Nitrogen fertilization is critical to achieve high yields and varies by previous crop (Table 7-11). Split applications of nitrogen should be made—half applied prior to seeding, and the remainder divided equally and applied after each cutting or grazing to achieve the most efficient use. Keep in mind possible volatilization losses of some forms of nitrogen when applied in the summer. Refer to Agronomy Facts AGF-205 or Bulletin E-2567, Tri-State Fertilizer Recommendations for Corn, Soybeans, Wheat and Alfalfa, for more information on nitrogen volatilization losses.

Harvest Management

Table 7-12 summarizes the guidelines for harvest management of the summer-annual grasses.

Direct-cut silage—Forage sorghum and sorghum-sudangrass hybrids are well suited as silage crops. Harvesting forage sorghum in the dough stage and sorghum-sudangrass in the heading stage should provide sufficient dry matter content for ensiling without wilting.

Greenchop or wilted silage—Sudangrass should be cut at 18 to 40 inches of growth. Sorghum-sudangrass hybrids should be cut when at least 30 inches tall, and pearl millet cut in late-boot to early-bloom stage.

Hay—Sudangrass, sorghum-sudangrass hybrids, and pearl millet can be cut for hay. Harvest when the grasses are vegetative (before heading) or the plant reaches a height of four feet. Always use a hay conditioner to mow and crush the stems to improve drying. Even with a hay conditioner, it is difficult to field cure these grasses adequately for safe storage as hay.

Grazing—All of the summer-annuals, except forage sorghum, are suitable for grazing. Sufficient height must be achieved before grazing to reduce animal health problems and to optimize production. Grazing plants that are less than 18 inches tall will weaken them, resulting in delayed regrowth. The chance of prussic acid poisoning is higher when grazing the sorghums before a full 18 inches of growth is present. Grasses in the vegetative stage are more palatable and nutritious. Trampling and wastage increases when grazing is delayed past the boot stage. Plants reach the grazeable height of 18 to 30 inches about six to eight weeks after planting. Rotational grazing or strip grazing management should be practiced. A sufficient number of animals should be placed on the pasture to graze the grass down in less than 10 days. After grazing, clip the residue to about eight inches if old stems remain. This improves forage quality for the next grazing period.

Animal Health Concerns

Prussic acid poisoning can occur when feeding sudangrass, sorghum-sudangrass hybrids, forage sorghum, or grain sorghum. These species contain varying concentrations of cyanogenic glucosides, which are converted to prussic acid, also known as hydrogen cyanide (HCN). As ruminants consume forage containing high levels of cyanide-producing compounds, prussic acid is released in the rumen and absorbed into the bloodstream, where it binds hemoglobin and interferes with oxygen transfer. The animal soon dies of asphyxiation. Prussic acid acts rapidly, frequently killing animals in minutes. Symptoms include excess salivation, difficult breathing, staggering, convulsions, and collapse. Ruminants are more susceptible than horses or swine because cud chewing and rumen bacteria help release the cyanide.

Species and varieties differ in prussic acid poisoning potential—sudangrass varieties are low to intermediate in cyanide potential; sudangrass hybrids are intermediate; sorghum-sudangrass hybrids and forage sorghums are intermediate to high; and grain sorghum is high to very high. Piper sudangrass has low prussic acid poisoning potential, and pearl millet is virtually free of cyanogenic glucosides.

Any stress condition that retards plant growth may increase prussic acid levels in plants. Hydrogen cyanide is released when leaf cells are damaged by frost, drought, bruising, cutting, trampling, crushing, or wilting. Plants growing under high nitrogen levels or in soils deficient in soil phosphorus or potassium tend to have high levels of cyanogenic glucosides. Fresh forage is generally higher in cyanide than in silage or hay because cyanide is volatile and dissipates as the forage cures.

Reducing the Risk of Prussic Acid Poisoning in Sorghum Species

When Grazing or Greenchopping

• Graze or greenchop only when grass exceeds 18 inches in height.
• Do not graze wilted plants or plants with young tillers.
• Do not graze plants during or shortly after a drought when growth has been reduced.
• Do not graze on nights when frost is likely. High levels of the toxic compounds are produced within hours after a frost occurs.
• Do not graze after a killing frost until the plants are dry. Wait five to seven days to allow the released cyanide to dissipate.
• After a non-killing frost, do not allow grazing because the plants usually contain high concentrations of toxic compounds. Once the first frost has occurred, grazing should not begin until five to seven days after a killing frost.
• Don’t allow hungry or stressed animals to graze young sorghum grass growth.
• Feeding green-chopped, frost-damaged plants has lower risk than grazing because animals have less ability to selectively graze damaged tissue; however, the forage can still be toxic, so feed with great caution. prussic acid toxicity, as do proper levels of phosphorus and potassium in the soil.

When Making Hay or Silage

• Frost-damaged annual sorghum grasses can be made into hay with little or no risk of toxicity. When plants are wilted enough to make dry hay, most of the volatile cyanide gas will have dissipated.
• Normal silage-making allows most of the cyanide to dissipate from frost-damaged annual sorghum grasses. Delay feeding of silage for six to eight weeks after ensiling.
• Silage that likely contained high cyanide levels at harvest should be analyzed for HCN content before feeding.

Nitrate poisoning can occur under conditions of high nitrogen fertilization, heavy manure applications, drought, overcast weather, or other stress conditions that retard plant growth. Under these stressful conditions, high nitrate levels accumulate in the crop. Once forage is fed, nitrate is converted to nitrite in the animal. When nitrite levels are high, the animal cannot metabolize it quickly enough, and nitrite inhibits oxygen transport in the blood. Symptoms include rapid breathing, fast and weak heartbeat, muscle tremors, staggering, and death—if corrective steps are not taken.

The same management precautions for prussic acid poisoning help prevent nitrate poisoning. Pearl millet does accumulate high nitrate levels leading to nitrate poisoning. As mentioned above, pearl millet does not accumulate prussic acid. High nitrate levels persist when forages are cut for hay, but ensiling the crop reduces nitrates by one-half. If you suspect that forage contains high nitrate levels, have it tested before feeding.

Poisoning of horses fed sudangrass, sorghum-sudangrass hybrids, and forage sorghum has been reported. The exact cause of poisoning is not known. Do not feed horses any of these summer annual grasses.

Brassica Crops

Forage brassicas are fast-growing annual crops that are highly productive and digestible. Crude protein levels range from 15% to 25% in the herbage and 8% to 15% in the roots, depending on nitrogen fertilization rate and weather conditions. The most commonly used forage brassica crops are rape, turnip, kale, and swede. They can be grazed from 80 to 150 days after seeding, depending on species (Table 7-12). These crops offer great potential and flexibility for improving livestock-carrying capacity from August through December. Spring-seeded brassicas boost forage supply in late summer. Summer-seeded brassicas extend the grazing season in late fall and early winter.

Rape (Brassica napus L.) is a short-season, leafy crop whose stems and leaves are eaten by the grazing animal; rape can also be green-chopped. It has fibrous roots, and each plant produces many stems. Rape regrows after harvest and is the easiest brassica species to manage for multiple grazings. Mature rape is excellent for fattening lambs and flushing ewes. Rape yield is generally maximized with two 90-day growth periods, but some varieties yield better with one 180-day growth period, while rape hybrids yield best with 60 days of growth for the first harvest followed by 30 days for the second harvest.

Turnip (Brassica rapa L.) is a fast-growing crop that reaches near maximum production 80 to 90 days after seeding. Roots, stems, and leaves are grazed. The relative proportion of tops and roots varies markedly with variety, crop age, and planting date. The crude protein concentration of roots (8% to 10% CP) is approximately one-half of that in turnip top growth; however, stockpiled tops are more vulnerable to weather and pest damage than roots.

Kale (Brassica oleracea L.) is a long-season, leafy brassica that produces some of the highest yields of the brassica family when it is spring-seeded. Some varieties are very cold tolerant, which allows grazing of leaves and stems into December and January most years. Stemless varieties reach about 25 inches in height, whereas narrow stem kale grows to five feet with primary stems two inches in diameter. Stemless kale (e.g., ‘Premier’) establishes quickly and reaches maturity in about 90 days. Narrow stem kale is slower to establish and requires 150 to 180 days to reach maximum production.

Swede (Brassica napus L.) is a long-season brassica that produces a large edible root-like turnip. Swede produces higher yields than turnip, but it grows more slowly and requires 150 to 180 days to reach maximum production. Swede produces a short stem when not shaded. If plants are shaded, it produces stems 30 inches tall. Swede does not regrow after harvest.

Hybrids of Chinese cabbage with rape, turnip, or swede can also be used for forage. Research information on the production and management of these hybrids is limited.

Establishment

Brassica crops germinate quickly and can be planted to provide either summer or late fall/winter grazing:

• Plant rape, turnip, and stemless kale in the spring (mid-April through May) to provide pasture in August and September.
• Plant rape and turnips in July and August to provide grazing in November and December.
• Plant swede and kale in the spring for grazing in November and December.

Brassica crops require well-drained soils with a pH between 5.3 and 6.8 for good production. Seeding rates for rape and kale are 3.5 to 4.0 lbs per acre, while turnip and swede are 1.5 to 2.0 lbs per acre. In the spring, use the higher side of the suggested seeding rates. Plant seeds in six- to eight-inch row spacings at ¼ to ½-inch deep in a firm seedbed. Apply 50 to 75 pounds of nitrogen per acre at seeding to stimulate establishment and seedling growth. Weed competition should be controlled during brassica establishment, otherwise stand establishment failures are very likely.

On conventionally prepared seedbeds, brassica seed can be broadcast and incorporated with cultipacking. No-till seeding into grain stubble or grass sod is recommended, but weeds and sod must be suppressed for two to three weeks to allow the brassicas to establish. Apply either paraquat or glyphosate for sod suppression. Another alternative is to apply a manure slurry or liquid nitrogen solution to burn the sod back, then no-till plant the brassica seeds. Brassicas can also be seeded with rye or other small grains to provide forage growth and protect the soil after brassicas are consumed.

Fertilization

Determine lime and fertilizer needs by a soil test. Adequate phosphorus and potassium are important for optimum growth. In addition to the nitrogen applied at planting (50 to 75 lbs per acre), another 70 lbs per acre should be applied when multiple grazings are planned with rape and turnips. This second application should be made from 60 to 80 days after seeding. Nitrogen application in a chemically suppressed grass sward tends to increase the efficacy of the suppressing herbicide. This reduces the proportion of grass in the brassica-grass sward, which is not always advantageous. Avoid excessive nitrogen and potassium fertilization to prevent animal health problems (see the section on Animal Health Concerns With Brassicas).

Harvesting

Although brassicas can be harvested for greenchop, they are most often grazed (Table 7-13). Rotational grazing or strip grazing helps reduce trampling and waste by livestock. Graze small areas of brassicas at a time to obtain efficient utilization. Rape is most easily managed for multiple grazings. Leave six to 10 inches of stubble to promote rapid regrowth of rape. When turnips are to be grazed twice, allow only the tops to be grazed during the first grazing. Turnip regrowth is initiated at the top of the root. Both rape and turnips should have sufficient regrowth for grazing within four weeks of the first grazing.

Stockpiling these crops for grazing after maturity should only be attempted when plants are healthy and free of foliar diseases. Some varieties are more suited for stockpiling because they possess better disease resistance. Do not grow brassica crops on the same site for more than two consecutive years to prevent the buildup of pathogens that limit stand productivity. Insect problems are not a consistent problem in Ohio.

Animal Health Concerns With Brassicas

Brassica crops are high in crude protein and energy, but low in fiber. The low fiber content results in rumen action similar to when concentrates are fed. Sufficient roughage must be supplemented when feeding brassicas to ruminant animals. If grazing animals are not managed properly, health disorders, such as bloat, atypical pneumonia, nitrate poisoning, hemolytic anemia (mainly with kale), hypothyroidism, and polioencephalomalacia, may occur.

These disorders can be avoided by following two guidelines:

• Introduce animals to brassica pastures slowly and avoid abrupt changes from dry summer pasture to lush brassica pasture. Do not turn hungry animals into brassica pasture, especially if they are not adapted to brassicas.
• Only two-thirds of the animal’s diet should be comprised of brassica forage. Supplement with dry hay or allow grazing animals access to grass pastures while grazing brassicas. No-tilling brassicas into existing grass pastures helps reduce the risk of these disorders, if sufficient grass growth is available for grazing.