How Grass Grows

How Grass Grows Lesson Description For the most part, small-acreage landowners often do not understand the basics of growing grass and legumes. They understand that they need to fertilize and water their lawns, as well as mow them when the grass gets too tall. However, in many cases, they do not give their pastures this same care. The first step is to understand how pasture plants grow. The next step is to identify the specific pasture plant species growing on their properties. Many small-acreage owners also feel that their animals need to be out in the pasture 24 hours a day so that they can “get some exercise,” when in reality most animals do not exercise alone, nor do they need access to food 24 hours a day. Participants must understand that pasture plants need time to grow before grazing and they need rest before regrazing. If properly managed, the amount of bare ground and weeds in the pasture will decrease. Lesson Objectives 1. Gain an understanding of the life cycle of forage plants from dormancy through spring and summer growing periods. 2. Be able to identify the vegetative and/or flowering parts of 10 to 14 common forage plants in their areas. 3. Learn how to estimate and calculate forage yield for their pastures. 4. Learn how to manage vegetation without grazing. How Grass Grows Handouts needed for participants 1. Grass Identification Sheets (PowerPoint note pages) 2. Grass Plant Parts Information Sheet 3. Forage Plant Characteristics Information Sheet 4. Identification of Plants Activity Sheet 5. Determining Forage Yield Activity Sheet 6. Forage Availability Estimates Information Sheet 7. Potential Pasture Production is High Information Sheet 8. Potential Pasture Production is Moderate Information Sheet 9. Potential Pasture Production is Low Information Sheet 10. Stubble Height and Regrowth Recommendations Information Sheet Supplemental Handouts Essentials of Forage Management, United States Department of Agriculture Pasture Management: Understanding Plant and Root Growth in the Fall, OSU Extension and WSU Extension Early Spring Forage Production for Western Oregon Pastures, OSU Extension Grass Plant Parts Information Sheet Grass plants consist of underground growth in the form of roots, which includes rhizomes, stolons, corms, bulbs, or fibrous masses; and above-ground growth consisting of stems, leaves and flowers/seeds. The collective name for the above ground portion of the grass plant is the culm or elongated internodes. The base of the above-ground portion of the grass plant is the crown, which is the junction between the roots and shoots. Growth begins here in the spring. The stem of the grass is divided into several joints. The joints or nodes are punctuated by a knobby swelling. The portion of the stem between two joints or nodes is called the internode. Each individual leaf of the grass has two distinct parts, the leaf sheath and the leaf blade. The leaf sheath is the portion of the grass blade that begins at the node below the collar and wraps Graphic adapted from North American Range Plants, 4th edition, by J. Stubbendieck, S L. around the stem. The leaf blade is above the Hatch and C.H. Butterfield. collar and separates from the stem at an angle, usually less than 90 degrees. The point where the leaf separates from the stem is called the collar. The collar consists of two parts called the auricle and ligule. The auricle is the turned, reinforced portion of the leaf blade as it leaves the collar region. The ligule is the outgrowth of the upper and inner side of the grass leaf at the point where it joins the collar region. It provides additional support for the leaf as it grows away from the stem. Not all grasses have auricles and/or ligules. The shape of the auricles and ligules can be very distinctive for individual grass species and can be an important plant identification factor. The flowering portion of the grass is called the inflorescence. The inflorescence is generally made up of many small branch-like clusters of flowers. These are termed spikelets. Spikelets consist of several florets or small flowers. At the base of the spikelet are glumes, which are dry chaff-like bracts or leaves. Often, these leaves or bracts provide protection for the florets above them. The glumes often have a sharp point or bristle termed an awn. The florets are the individual flowers, which will later form individual seeds. Each floret has two leaves or petals surrounding the actual reproductive plant parts. The outer leaf or petal is termed the lemma, the inner, smaller one is termed the palea. Forage Species Characteristics Information Sheet, page 1 of 2 Plant Species Growth Habit Growing Point Location Seedling Vigor Yield Potential Longevity Winter Hardiness Drought Tolerance Flood Tolerance Saline Tolerance Alkaline Tolerance Acid Tolerance Compatability With Other Species Palatability Grazing Recovery Rate Pasture Hay Other X cover crop Stop Grazing Height Comments Cool Season Grasses Annual ryegrass bunch ground excellent moderate annual moderate moderate excellent poor poor moderate moderate good medium X Basin wildrye bunch elevated poor to moderate high long excellent excellent moderate good good moderate moderate good slow X Crested wheatgrass bunch ground good moderate long excellent excellent good moderate good moderate moderate good medium X X wildlife sod ground moderate high long excellent moderate excellent moderate moderate moderate good excellent rapid X X wildlife, filter bunch elevated good high medium excellent excellent moderate moderate poor moderate good good medium X X erosion control 6 inches Kentucky bluegrass sod ground good moderate long excellent poor good poor poor moderate poor good rapid X X wildlife, recreation 2 inches Meadow brome sod elevated moderate moderate long excellent good poor poor poor moderate good good rapid X X wildlife 3-4 inches Orchardgrass bunch ground good high medium good excellent poor poor poor moderate good excellent rapid X X wildlife Perennial ryegrass bunch ground good moderate medium poor to moderate poor moderate moderate moderate good good excellent rapid X X lawn, silage >2 inches Pubescent wheatgrass bunch elevated good high medium excellent excellent moderate moderate poor moderate good good medium X X erosion control 6 inches sod elevated good high long excellent moderate excellent moderate moderate moderate poor good rapid X X filter, erosion 6-8 inches Russian wildrye bunch ground moderate moderate long excellent excellent poor good good poor poor good rapid X X wildlife Siberian wheatgrass bunch ground good moderate long excellent excellent moderate moderate moderate poor poor good rapid X ? wildlife, reclamation Slender wheatgrass bunch elevated excellent moderate short good moderate poor good good poor good good medium X X wildlife, reclamation shade tolerant; allow to set seed every other year Smooth brome sod ground poor to moderate moderate medium good good moderate moderate moderate good moderate good medium X X silage can be invasive Soft chess/ blando brome sod ground excellent moderate annual N/A moderate poor moderate moderate moderate moderate good medium X wildlife Streambank wheatgrass sod ground moderate moderate long good good moderate good good moderate good good medium X wildlife Tall fescue bunch ground excellent moderate long excellent poor moderate good good good moderate to good good medium X Thickspike wheatgrass sod ground moderate moderate long good good moderate good good moderate good good medium bunch elevated good moderate short excellent poor moderate moderate moderate good good good sod ground moderate moderate long excellent moderate moderate moderate moderate poor good good Garrison creeping foxtail Intermediate wheatgrass Reed canarygrass Timothy Western wheatgrass moderate shade tolerance graze in winter, when dormant 3 inches competes with cheat grass no dormancy period; invasive can be can be invasive shade tolerant plant endophyte-free varieties; easily damaged when frozen can be invasive 3 inches 4 inches can be invasive; let it set seed for the next year X 2 inches can be invasive, plant endophyte-free varieties X X 2 inches slow X X 3 inches slow to medium X 3-4 inches Forage Species Characteristics Information Sheet, page 2 of 2 Plant Species Growth Habit Growing Point Location Seedling Vigor Yield Potential Longevity Winter Hardiness Drought Tolerance Flood Tolerance Saline Tolerance Alkaline Tolerance Acid Tolerance Compatability with other species Palatability Grazing Recovery Rate Pasture Hay Other Stop Grazing Height Comments 50% starting height graze during active growth in spring/summer 8 inches one month rest before freeze 8-12 inches one month rest before freeze 8 inches one month rest before freeze Warm-Season Grasses Alkali sacaton bunch ground moderate moderate moderate moderate good good good excellent poor moderate good medium X Big bluestem bunch ground moderate low moderate moderate good to moderate poor poor poor moderate good excellent medium X Indiangrass sod elevated moderate moderate moderate moderate moderate poor moderate good good good good medium Little bluestem bunch ground moderate moderate moderate moderate excellent poor poor moderate moderate good good medium X Sideoats grama bunch ground moderate moderate moderate moderate moderate poor moderate moderate moderate good good medium X wildlife Sorghumsudangrass sod elevated high high annual poor moderate poor moderate moderate moderate good good medium to rapid X cover crop Sudangrass sod elevated high high annual poor moderate poor moderate moderate moderate moderate good medium X cover crop Switchgrass sod elevated moderate high long good moderate moderate moderate moderate moderate moderate good medium X X erect elevated high high long excellent good poor good good poor good excellent rapid X X prostrate elevated moderate moderate short? moderate poor good poor poor good good good medium X X Birdsfoot trefoil erect elevated poor moderate moderate good moderate good poor poor moderate good excellent medium X X Cicer milkvetch erect elevated poor moderate long excellent moderate good moderate moderate poor good excellent medium X X Red clover erect elevated moderate moderate moderate excellent moderate moderate moderate moderate moderate good good medium X X Sainfoin erect elevated good moderate long excellent good poor moderate moderate moderate good excellent medium to slow X ? Subterranean clover prostrate elevated moderate moderate to low annual moderate good good poor poor good good good rapid X X Strawberry clover prostrate elevated moderate low moderate good poor good good good good good good medium X White clover prostrate elevated good moderate moderate good poor moderate moderate moderate moderate good excellent rapid X X wildlife 2 inches Yellow / white sweetclover erect elevated poor moderate short good good poor moderate moderate moderate moderate good medium X X cover crop 6 inches X X wildlife wildlife wildlife one month rest before freeze depends on season one month rest before freeze; can be invasive 2 inches bloat hazard; rest before freeze >2 inches bloat hazard; make sure to innoculate 4-6 inches non-bloat; allow to reseed every 3 years 5 inches do not use for sheep during breeding season Legumes Alfalfa Alsike clover cover crop silage non-bloat non-bloat; moderate shade tolerance cover crop 2 inches bloat hazard bloat hazard; can cause illness in animals Determining Forage Yield Activity Sheet, page 1 of 5 Forage yield is the actual amount of forage dry matter available in a pasture or rangeland on a per acre basis. When you calculate forage dry matter, it is comparable to cutting and drying hay. Rather than mowing drying, and weighing all of the useable forage in an acre of your pasture, we will sample from a small area to estimate the total forage yield. Equipment needed: • Hoop • Grass clippers • Small to medium sized paper grocery bags, pre-weighed. Write the weight on bag. Brown paper lunch bags weigh 6-8 grams. • Hand-held spring scale that weighs in grams. A 300- to 500-gram scale works best. 8-foot circumference clipping ring It’s easiest to construct a cable hoop by bolting together the ends of an eight-foot-long, one-quarterinch cable. This cable is available at most farm and ranch supply stores for a cost of about $5. A hand-held spring scale is available from forestry, animal health or surveying equipment stores. A 300to 500-gram scale works best. Forestry Suppliers has the clippers and scale for reasonable prices, 1800-647-5368, www.forestry-suppliers.com. The Pesola Medio-Line Spring Scale, 300 grams, stock #93013 and model #40300, is $34.50. They also have clipping shears for smaller hands, stock #81191, at $16.95. Ben Meadows, 800-241-6401, has Corona Grass Trimmers for $21.95. Now we have an 8-foot-circumference circle. This circle is roughly 30 inches in diameter. We want to check the actual forage in our pasture. For simplicity, clip areas that are not grazed. Use a representative area of the pasture, not the high or the low producing areas, but the moderate areas. We also want to take three or so different samples and then average the results for greater accuracy. Determining Forage Yield Activity Sheet, page 2 of 5 • • • • • • • • Preweigh and label your paper bag. Throw the cable hoop in the area determined to be representative of the forage in the pasture. Clip all the forage within the circle down to the ground and place it in the preweighed paper bag. Depending on how much forage is clipped, you may need more than one bag for each hoop. Be sure to label the bags with the pasture number, date, and whether it is you first, second, third, etc. throw of the hoop. Forage requirements are based on air-dry weight, so let the forage dry several days in the bags, allowing the bags to remain open. Another option is to dry the forage on a cookie sheet in an oven at 100 degrees. The forage should look and feel like hay when it is dry. The next day, weigh the bag(s) using the gram scale. Be sure to subtract the weight of the bag from the weight of the bag plus the forage. Clip, dry and weigh forage from several different locations in the pasture. Average the weights in grams. This is the weight of forage, in grams, for an 8-foot circumference circle or a 30-inch diameter circle of your pasture. To convert the grams of forage available in an 8-foot circumference circle to the pounds of forage per acre, multiply the gram weight by 20. This measurement is the total pounds of forage per one acre of pasture. Once you have determined the average pounds of forage per acre for this pasture, multiply by the number of acres in the pasture to calculate the total pounds of forage. As we discussed before, the best management practice for grazing is to take half and leave half. That means grazing about half of the plant from the top down. This leaves the plant plenty of vegetation to continue making food for itself from sunlight (photosynthesis) and plenty of cover to protect the soil from drying out during the growing season. In order to graze either pasture or rangeland in a sustainable manner, a ‘key species’ should be predetermined. This is the forage specie that you manage for. When the suggested grazed height is reached, it is time to rest the pasture. The idea is to evenly graze the forage so that some plants are not left ungrazed. When plants are not grazed initially, they usually are not chosen the rest of the growing season. Instead, previously grazed plants are regrazed after a rest, over and over. On some rangelands, shrubs may be the dominant plants. If your grazing animals, such as cows or horses, cannot eat the shrubs, there may not be much useable forage. Use your calculations from clipping or soil survey production estimates in order to apply the calculations below. A method for preliminary estimates on usable forage for rangeland and pasture is provided. Determining Forage Yield Activity Sheet, page 3 of 5 On rangeland, if we start with 100 percent of the plants and take half and leave half (100 percent x 50 percent), then 50 percent remains usable. Animals will not eat 25 percent of the available species that grow on the rangeland (50 percent x 75 percent), reducing usable forage to 37.5 percent. Of the 37.5 percent that is left, the animals will trample or destroy another 25 percent (37.5 percent x 75 percent) leaving only 28 percent. For ease of calculation, we’ll round the number to 25 percent. The actual useable forage in a rangeland setting may be only about 25 percent of the available forage! Note that the terms “available” and “usable” are two different concepts. Available forage includes all plant material growing in a pasture that animals have access to, while useable forage is what the grazing animal will actually eat. For pasturelands, the calculations are a little different. First, on pastureland as on rangeland, starting with 100 percent of the plants and grazing half (100 percent x 50 percent) leaves 50 percent. However, on pasture, animals will usually eat all of the available species unless the pasture is overrun with weeds. If this is case, weed control measures and/or renovation may be options. Assuming the pasture is in good condition, only about 25 percent will be spoiled with trampling or manure (50 percent x 75 percent) yielding 37.5 percent, which we’ll round to 35 percent. The actual usable forage in a healthy pasture is only about 35 percent of the available forage. Your goal is to rest the pasture after the ‘key specie’ has been grazed down to the appropriate height for that species. Determining Forage Yield Activity Sheet, page 4 of 5 Sample calculation The average clipping weight (total weight less the bag weight, averaged for several samples) is 200 grams. To convert from 200 grams per 8-foot circumference circle (30 inch diameter) to pounds per acre, multiply 200 by 20 to get 4,000 pounds per acre of total forage. 4,000 pounds multiplied by 25 percent = 1,000 usable pounds per acre for rangeland 4,000 pounds multiplied by 35 percent = 1,400 usable pounds per acre for pasture To calculate total forage in a given pasture, multiply the pounds per acre times the number of acres in the pasture. Determining forage yield – sample problem You have clipped three representative areas in Pasture 1. The pasture is 3 acres in size. The three samples you took weighed 251 grams, 191 grams and 281 grams. The lunch bags weigh 8 grams each. How many pounds of forage are useable in Pasture 1 per acre? Assume Pasture 1 is a pasture in reasonably good condition. How many useable pounds of forage per acre would Pasture 1 provide if it were a rangeland or native pasture? How many pounds of forage are useable in the entire introduced species pasture? How many pounds of forage are available in the entire native pasture? Determining Forage Yield Activity Sheet Answer Key, page 5 of 5 The actual weights of the three samples from Pasture 1, after subtraction of the 8-gram bag weight, are: 251 – 8 = 243 grams 191 – 8 = 183 grams 281 – 8 = 273 grams The average weight of forage, in grams is: (243 + 183 + 273) = 699 = 233 grams 3 3 Converting grams to pounds per acre: 233 x 20 = 4660 pounds total forage Available forage = 35 percent of total forage or 4660 pounds x 35 percent (0.35) = 1631 useable pounds per acre Available forage per acre for rangeland or native pasture would be 4660 x 25 percent (0.25) = 1165 useable pounds per acre Available forage for all 3 acres of “reasonably good condition” pasture = 1631 x 3 = 4893 useable pounds of forage Available forage for 3 acres of rangeland or native pasture = 1165 x 3 = 3495 useable pounds of forage Total forage, available forage, and usable forage are three completely different concepts. Total forage includes everything growing in a pasture. Available forage is what the grazing animals have access to and could potentially eat. Usable forage is what they prefer to eat and what they do not damage. Forage on very steep slopes may not be available to some animals. Usable forage that has been urinated on is no longer useable. Total forage would include shrubs/forbs that the animals would not eat. On range and pasture, the 25 percent and 35 percent estimates (respectively) take much of these factors into account. Forage Availability Estimates Information Sheet If you cannot clip your pasture, there are other methods for estimating available forage. The forage availability estimates provided below are for use with rotational grazing systems on pasturelands. These figures do not apply to native or rangeland pastures. The numbers come from a County Soil Survey Report, ‘Land Capability and Yields.’ They are based on the figures for ‘optimum production with a high level of management for tons of hay.’ Forage Availability Estimates – Pasturelands Hay yield (tons/acre/year) 5.5 Forage availability (pounds/acre/year) 3850 4.5 3150 4 3.5 3 2800 2450 2100 2.5 1750 2 1.5 1 1400 1050 700 Whenever possible, it is best to clip the grasses to provide accurate forage production figures. Native or rangeland pastures must be clipped to provide good estimates. The soil survey report has a section on ‘rangeland productivity,’ but this data is for specific plant species and relative percentages of those species found on that particular soil in a pristine condition. In other words, the species and the percentage of that species in the plant community listed reflect species composition on the range before the introduction of domestic grazing animals. Due to grazing pressure, the type and relative abundance of species present today will differ from that listed. Seasonal grazing lengths Suggested grazing duration in spring is four to five days; regrowth period is 10 to 14 days while the grasses are growing fast. Suggested grazing duration in summer is nine to 10 days; regrowth period is 21 to 30 days. Grass growth is slowing down, and much of the plant energy is devoted to seed production. Suggested grazing duration in late summer is 12 to 15 days; regrowth period is 30 to 45 days. The grass plants are preparing for dormancy by storing food reserves in the root. The length of regrowth period is shorter for irrigated pastures and longer for dryland pastures. In many western regions, there may not be any summer regrowth on dryland pastures, although some fall regrowth may occur. Note that the above suggestions are simply guidelines for grazing and resting. Watch the grazed height of your key specie carefully to help you determine when to rest a pasture. You can graze the pasture again when most of the key specie has reached suggested grazing heights. If there hasn’t been any regrowth, then there shouldn’t be any regrazing. Potential for Pasture Production is High Information Sheet These pastures have adequate soil depths with more than 20 inches for effective root growth; desirable soil textures (silty, sandy or clay loams); good soil tilth; good soil-moisture-holding capacity; and free of significant amounts of salts or alkali. Topography permits good distribution of irrigation water. NRCS soil reports, map unit descriptions, engineering soil properties, physical properties plus rangeland production or irrigated yields by map unit will provide the necessary information about soil limitations These assessments apply to irrigated or subirrigated pastures, or pastures that receive more than 20 inches of annual precipitation. This is one method for determining your pasture condition and estimated production. Note that pasture grazing efficiencies are not considered in this chart. MANAGEMENT LEVEL HIGH Condition/Production GOOD Condition/Production FAIR Condition/Production LOW Condition/Production 1. Intensity of rotation 7 or > pastures grazed for 2 to 4 days per rotation or stripped grazed 4 or 5 pastures grazed for 4 to 10 days per rotation 2 or 3 pastures grazed for 10 to 20 days per rotation 1 pasture grazed for long periods or continuously 2. Available forage (average height with leaf in vertical position) Foliage height at beginning of grazing season is 12 inches or more Foliage height at beginning of grazing is 8 - 10 inches Foliage height at beginning of grazing is 6 inches Foliage height at beginning of grazing is 4 inches or less 3. Degree of use Stubble height end of graze season is 4 inches or more GRAZING MANAGEMENT 4. Maintain stand (average height with leaf held in vertical position) Stubble height at end of graze season is 2 to 3 inches Stubble height at end of grazing season is < 2 inches" Foliage height regrowth at freeze-up is 5 to 8 inches Foliage height regrowth at freeze-up is 3 inches 3 weeks regrowth between grazings 2 weeks regrowth between grazings Soil moisture maintained. 2 or more irrigations during regrowth period Soil moisture usually adequate,1-2 irrigations during regrowth period Irrigated immediately after livestock are removed from pasture Irrigated several days after livestock are removed from pasture Plants are stressed between irrigation cycles, rarely more than one irrigation cycle during regrowth period Irrigation frequently delayed a week after livestock are removed Soil is firm when grazed Soil is more firm than not before grazing resumes Soil frequently wet and soft when grazed 30 to 40 percent high yielding legumes 20 percent legumes, usually alfalfa Good stands of highly adapted and productive grass species Good stands of well adapted and productive grass species Stands lack vigor, poorly adapted/low producing species that include weeds Poor stand and production with low vigor, weeds and bare ground Regular soil testing:120-200 lbs actual N per acre applied in 2-3 applications Regular soil testing: 100-120 lbs actual N per acre applied in 2 applications Occasional soil testing: 30-60 lbs actual nitrogen per acre applied to grass Never test soil; no nitrogen applied Regular soil testing: applied to supply 55-65 lbs P2O5 per year Regular soil testing: applied to supply 45-55 lbs P2O2 per year Random soil testing: < 30 lbs P2O2 applied at seeding but rarely thereafter Never test soil; no phosphorus applied 1. Clipping Rough, stemmy growth clipped as needed Rough, stemmy growth clipped as needed Stemmy growth rarely clipped Never clipped 2. Dragging Manure spread by dragging spring/summer Manure spread by dragging spring/summer Manure seldom spread by dragging Never dragged 9.1 + AUM /acre or 9,100 + lbs/acre, based on 1,000pound animal (9.1 x 1,000). See soil map unit report for estimated production. 6.1 to 9 AUM/acre or 6,100 to 9,000 lbs/acre, based on 1,000-pound animal (6.1 x 1,000). See soil map unit report for estimated production. 3.1 to 6 AUM/acre or 3,100 to 6,000 lbs/acre based on 1,000-pound animal (3.1 X 1,000). See soil map unit reports for estimated production. 1 to 3 AUM/acre or 1,000 to 3,000 lbs/acre based on 1,000-pound animal (1 X 1,000). See soil map unit reports for estimated production. 5. Regrowth period Foliage height regrowth at freeze-up is 8 inches or more Stubble height at end of graze season is 3 to 4 inches 4 or more weeks regrowth between grazings Foliage height regrowth at freeze-up is less than 2 inches Continuous graze w/out regrowth period IRRIGATION 1. Frequency of irrigation cycles 2. Time 3. Time lapsed after irrigation before grazing Too much or too little irrigation Too much or too little irrigation Soil is Irrigated while the pasture is grazed COMPOSITION 1. Legumes 50 percent of yield from high producing legumes 2. Grasses < than 10 percent legumes, usually white clover FERTILIZER 1. Nitrogen (N) 2. Phosphorus (P) MAINTENANCE Expected Production - Animal Unit Months per acre per year, based on a 180-day growing season Potential for Pasture Production is Moderate Information Sheet Moderate, but limited by one or more of the following soil factors: soil depth is between 10 and 20 inches for effective root development; soil texture includes sticky clays more than 10 inches deep; salt and/or alkali moderately inhibits growth; soils with desirable textures but low water storage capacity due to gravel or cobbles; or a combination of slope and texture that makes good water management impractical to achieve. NRCS soil reports, map unit descriptions, engineering soil properties, physical properties plus rangeland production or irrigated yields by map unit will provide the necessary information about soil limitations These assessments apply to irrigated or subirrigated pastures, or pastures that receive more than 20 inches of annual precipitation. This is one method for determining your pasture condition and estimated production. Note that pasture grazing efficiencies are not considered in this chart. MANAGEMENT LEVEL GOOD Condition/Production FAIR Condition/Production 4 or 5 pastures grazed for 4 to 10 days per rotation 2 or 3 pastures grazed for 10 to 20 days per rotation Foliage height at beginning of grazing season is 8-10 inches Foliage height at beginning of grazing is 6 inches LOW Condition/Production GRAZING MANAGEMENT 1. Intensity of rotation 2. Available forage (ave ht with leaf in vertical position) 3. Degree of use 4. Maintain stand (average height with leaf held in vertical position) 5. Regrowth period IRRIGATION 1. Frequency of irrigations 2. Time Stubble height at end of graze season is 3 to 4 inches Foliage height regrowth at freeze-up is 5 to 8 inches Foliage height regrowth at freeze-up is 3 inches 3 weeks or more regrowth between grazings 2-3 weeks regrowth between grazings Soil moisture usually adequate. 1 or 2 irrigations during regrowth period Plant stress between irrigations, rarely more than 1 irrigation cycle during regrowth period Irrigation frequently delayed a week after livestock are removed Irrigated several days after livestock are removed from pasture 3. Time lapse after irrigation before grazing Stubble ht end of graze season is 2 to 3 inches 1 pasture grazed for long periods or continuously Foliage height at beginning of grazing is 4 inches Stubble heightt end of graze season is < 2 inches Foliage height regrowth at freeze-up is < 2 inches Continuously grazed w/out regrowth period Too much or too little irrigation Too much or too little irrigation Soil usually firm before grazing resumes Soil frequently wet and soft when grazed Irrigated while grazed 1. Legumes 30 to 50 percent legumes, usually alfalfa 2. Grasses Good stands of well adapted and productive grass species 20 percent legumes, usually alfalfa Stands lack vigor, poorly adapted/low producing species that include weeds < than 10 percent legumes, usually white clover Poor stand and production with low vigor, weeds and bare ground COMPOSITION FERTILIZER 1. Nitrogen (N) 2. Phosphorus (P) Regular soil testing: 100-120 lbs of actual N/ac applied in 2 applications Regular soil testing: applied to supply 45-55 lbs P2O5 per year Occasional soil testing: 30-60 lbs of actual N/acre applied in late spring Random soil testing: < 30 lbs P2O5 applied at seeding but rarely thereafter Rough, stemmy growth clipped as needed Manure spread by dragging spring/summer Stemmy growth rarely clipped Manure seldom spread by dragging Never clipped Never dragged 3.5 to 5 AUM/acre or 3,500 to 5,000 lbs/acre, based on 1,000pound animal (3.5 x 1,000). See soil map unit report for estimated production. 2.1 to 3.5 AUM/acre or 2,100 to 3,500 lbs/acre, based on 1,000-pound animal (2.1x 1,000). See soil map unit report for estimated production. 1 to 2 AUM/acre or 1,000 to 2,000 lbs/acre based on 1,000pound animal (1 X 1,000). See soil map unit reports for estimated production. Never test soil; no nitrogen applied Never test soil; no phosphorus Applied MAINTENANCE 1. Clipping 2. Dragging Expected Production - Animal Unit Months per acre per year, based on a 180-day growing season Potential for Pasture Production is Low Information Sheet, Even under good management practices, potential is low because of one or more of the following factors: soil depth for effective root development is less than 10 inches; soil texture is coarse or sandy with little water-holding capacity; sodium is present, causing crusting; poor water intake characteristics; salt and/or alkali is severely limiting; or slopes are so steep that application of irrigation water is irregular and not very effective. NRCS soil reports, map unit descriptions, engineering soil properties, physical properties plus rangeland production or irrigated yields by map unit will provide the necessary information about soil limitations These assessments apply to irrigated or subirrigated pastures, or pastures that receive more than 20 inches of annual precipitation. This is one method for determining your pasture condition and estimated production. Note that pasture grazing efficiencies are not considered in this chart. MANAGEMENT LEVEL GOOD Condition/Production LOW Condition/Production More than 1 pasture grazed for 10 to 20 days per rotation 1 pasture grazed continuously Foliage height at beginning of grazing season is 4 inches or more Foliage height at beginning of grazing is less than 4 inches Stubble height at end of grazing season is at least 3 inches Stubble height at end of grazing season is less than 3 inches Foliage height regrowth at freeze-up is 3 inches or more Foliage height regrowth at freeze-up is less than 3 inches 2 weeks or more for regrowth between grazings Continuously grazed with no regrowth periods Soil moisture usually adequate. 1 or 2 irrigation cycles during regrowth period Too much or too little irrigation GRAZING MANAGEMENT 1. Intensity of rotation 2. Available forage (average height with leaf in vertical position) 3. Degree of use 4. Maintenance of stand (average height with leaf held in vertical position) 5. Regrowth period IRRIGATION 1. Frequency of irrigations 2. Time lapse after irrigation before grazing Soil is sometimes wet and soft when grazed. Occasionally irrigation occurs during grazing Grazing pastures during irrigation is a common practice COMPOSITION 1. Legumes Very few or no legumes Very few or no legumes 2. Grasses Mostly desirable species Low producing species, mostly weeds, invaders, and/or bare ground FERTILIZER 1. Nitrogen Usually not used No nitrogen applied 2. Phosphorus Usually not used No phosphorus applied 1. Clipping Stemmy growth rarely clipped Never clipped 2. Dragging Droppings are seldom spread by dragging Never dragged 1.6 – 2 AUM/ac or 1,600-2,000 lbs/ac, based on 1,000-pound animal (1.6 x 1,000). See soil map unit report for estimated production. .05 - 1.0 AUM/ac or 50-1,000lbs/ac, based on 1,000-pound animal (.05 x 1000). See soil map unit report for estimated production. MAINTENANCE Expected Production - Animal Unit Months per acre per year, based on a 180-day growing season Stubble Height and Regrowth Recommendations Information Sheet, page 1 of 2 Suggested Height at Start of Grazing (inches) Growth Stage at Start of Grazing Minimum Stubble Height (inches) Tall fescue 8 Early boot 4 Orchardgrass 8 Boot 3 Smooth bromegrass 8 Early boot 4 Meadow bromegrass 8 3 Meadow foxtail 10 4 Basin wildrye 10 8 Crested wheatgrass 4 Vegetative 2 Tall wheatgrass 10 Vegetative 6 Intermediate wheatgrass 8 Early boot 4 Pubescent wheatgrass 8 Early boot 4 Timothy 8 Boot 3 Kentucky bluegrass 6 Vegetative 3 Reed canarygrass 12 Vegetative 4 6-18 Mid to late bud 2 Red clover 6 Early bloom 3 Alsike clover 6 Early bloom 2 Sweetclover 8 Ladino clover 4-8 Grasses Legumes Alfalfa 6 Early bloom Strawberry clover 3 2 Broadleaf birdsfoot trefoil 8 Early bloom 3 Narrowleaf birdsfoot trefoil 8 Sainfoin 12 Early bloom 6 Cicer milkvetch 8 Early bloom 4 3 These figures are from Nevada. Each state may need to tailor this information to local climate and growing conditions. Stubble Height and Regrowth Recommendations Information Sheet, page 2 of 2 Species Regrowth time (days) Alfalfa 28-40 Trefoil 24-30 Clover 20-26 Sainfoin 28-40 Milkvetch 24-30 Orchardgrass 20-36 Tall fescue 20-36 Timothy 28-36 Intermediate wheatgrass 24-30 Smooth bromegrass 24-30 These figures are estimates for Nevada. Each state may need to tailor this to local climate and growing conditions. The values are for dryland conditions. Regrowth rates for irrigated pastures will be different. The data is representative of hot summer conditions when plant growth slows considerably. The above figures do not apply during the early spring when grasses are growing fast. At that time of year, regrowth may occur in as little as 10 to 14 days. As the weather gets warmer and rainfall slows down, so does grass growth. How Grass Grows Glossary, page 1 of 2 Annual: Plant that completes its life cycle, growing from a seed to producing seed, in one growing season. Auricle: The turned, reinforced portion of the leaf blade as it leaves the leaf sheath at the collar region. Awn: Bristle-like growth extending from the lemma of a floret. Biennial: A plant that completes its life cycle in two years. First year growth consists of low growing leaves; the second season growth includes flowers and seeds. Bunchgrass: Grass that propagates by seed and basal tillering only (no rhizomes), forms clumps, not sod. Collar: The point where the leaf separates from the stem; the collar consists of two parts called the auricle and ligule. Cool-season grass: Grass species adapted to rapid growth during the cool, moist period of the year; this type of grass is usually dormant during hot weather. Crown: The base of the above-ground portion of the grass plant at the junction of roots and shoots. Culm: The collective name for the above-ground portion of the grass plant; jointed stem of a grass plant, the true stem, and elongated internodes. Forage yield: The actual amount of useable forage, generally reported on a per acre basis. Forbs: Broad-leaved, flowering, herbaceous plants. Florets: The individual flowers on a spikelet, which will later form individual seeds on a grass. On a legume, it is an individual flower, usually belonging to a cluster. Glabrous: Smooth, devoid of hair or pubescence. Glumes: Dry chaff-like bracts or leaves at the base of the spikelet; often these leaves or bracts provide protection for the florets above them. Herbaceous: Plants that do not produce wood; a plant having little or no woody tissue Inflorescence: The flowering portion of the grass, generally made up of many small branch-like clusters of flowers called spikelets. Also called a seed head. Internode: The portion of the stem between two joints or nodes. Leaf blade: The portion of the grass blade that separates from the stem at an angle (usually less than 90 degrees), above the collar. Leaflet: Subdivision of compound leaves, an individual leaf petal. Leaf sheath: Portion of the grass blade that begins at the node and that wraps around the stem below the collar. Legume: Plant of the pea family, generally has the ability to fix nitrogen from the atmosphere into the soil, where it becomes available to plants. How Grass Grows Glossary, page 2 of 2 Lemma: Chaffy bract or scale opposite the palea, the outer leaf or petal of the floret; it surrounds the actual reproductive plant parts. Ligule: The outgrowth of the upper and inner side of the grass leaf at the point where it joins the leaf sheath. It provides additional support for the leaf as it grows away from the stem. Nodes: Joints of the grass stem, each supporting a new leaf , punctuated by knobby swelling. Paddock: Aka sacrifice area. Small field or enclosure used to confine animals when they are not grazing, generally for horses. Palea: Chaffy bract or scale opposite the lemma, the inner leaf or petal of the floret; it surrounds the actual reproductive plant parts. Pasture: Ground or field suitable for grazing. Perennial: Plant that lives for three or more years, even though some perennials die down to the ground each year. Petiole: Leaf stalk that attaches legume leaf blade to the stem. Pubescence: Hair, hairy. Raceme: Inflorescence in which flowers or spikelets are singly supported along a main axis. Rangeland: Land that is dominated by native vegetation. Rhizome: Underground stem, usually horizontal, capable of producing new shoots and roots at the nodes. Sod: Top few centimeters of soil permeated by and held together with plant roots. Sod-forming grass: Grass that propagates by seed and vegetatively by rhizomes and/or stolons to form a sod. Spikelets: Small branch-like clusters of flowers, each consists of several florets or small flowers. Stipule: One of the small, paired leaf-like appendages at the base of a legume leaf. Stolon: Trailing or lateral stem forming at or below the soil surface, capable of rooting and sending up new shoots at the nodes. Tillering: To put out new plant shoots from the root. Toothed: Sawteeth-like projections on the margins of a leaf blade Warm-season grass: Grass species that makes its major growth during the warmer part of the year.