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How Grass Grows. Developed by: Wendy Williams, NRCS, Bozeman, Montana. UNCE, Reno, Nev. Topics to be covered:. How plants make food Legumes and grasses How pasture plants grow Growth and reproduction Managing growing points Determining forage yield. How plants make food for growth.
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How Grass Grows Developed by: Wendy Williams, NRCS, Bozeman, Montana UNCE, Reno, Nev.
Topics to be covered: • How plants make food • Legumes and grasses • How pasture plants grow • Growth and reproduction • Managing growing points • Determining forage yield
What plants are growing on my property? • Legumes • Grasses • Weeds (we’ll talk about them later) • Woody shurbs • Trees UNCE, Reno, Nev.
flower leaf stem leaflet stolon taproot Legumes Parts of a legume
How legumes grow • Vegetative growth • Bud stage • Flowering NCSU
Grasses Parts of a grass plant
Grasses consist of several growth segments Each segment contains a: • Leaf • Node • Internode • Axillary bud or potential bud – can produce a new stem or tiller NRCS, Bozeman, Mont.
Penn State Univ. OSU 2 tillers developing from the crown of the plant A joint (node)
Growing Points • Location where cells divide and produce new growth • Occur close to the ground early in the growing season • Become elevated above ground as the growing season progresses NRCS, Bozeman, Mont.
Stages of grass growth • Vegetative • Growth of leaves • Elongation • Lengthening of stem internodes, also called jointing • Boot stage is the end of elongation • Reproductive • Development of seedhead and seed
Plant reproduction • Grass plants reproduce by forming seed heads • Some plants also reproduce by sending out spreading roots or shoots USDA NRCS UNCE, Reno, Nev.
Regrowth Intact growing points Growing point level Short-shoot phase of growth Regrowth Growing points removed; must regrow from basal buds Long-shoot phase of growth (elongated internodes)
Forage growth and management USDA NRCS
Forage growth patterns • Growing points at ground level • Growing points on the stem • Growing points at the stem tips Smooth brome
Carbohydrate reserves (food) • Stored in roots, rhizomes, stolons and base of stem • Used for first spring growth of dormant plants • Allow rapid regrowth from stubble Penn State Univ. Kentucky bluegrass rhizome
Take-half and Leave-half Adapted from NRCS, Bozeman, Mont. by A. Miller
Nutrient content by plant growth stage A B C www.ag.ndsu.edu by A. Miller
Managing for productivity • Early to mid-season, maximum forage production can be obtained by keeping the plant in a vegetative state by preventing seed head production • Depending on the species, you may want to let the grass form a seed head at the end of the season
Identifying grasses Plant life cycles • Annual • Biennial • Perennial OSU
Cool-season plants • Optimum temp. range 65 to 75 degrees F • Productive in spring and fall • Reduced growth in summer • Higher in crude protein • Respond to nitrogen fertilizer • Examples: • orchardgrass, • fescues, • perennial ryegrass, and • bromes
Warm-season plants • Better at using atmospheric nitrogen • Grow best at high temperatures (90 to 95 degrees F) • Lower in protein but protein is more efficiently used by animals • Triggered by day lengths • Examples: • big and little bluestem, • switchgrass, • Indiangrass, and • sudangrass
Cool-season bunchgrasses • Growth occurs in early spring or late fall • Grows in bunches or clumps • Grass propagates by seed only • More elevated leaves • Grazing must be managed to optimize productivity
Cool-season sod-forming grasses • Growth occurs in early spring or late fall • Growth forms a mat of roots or sod • Plants propagate from both seed and rhizomes or stolons • More tolerant of grazing
Warm-season sod-forming grasses • Growth occurs in late spring to early summer • Growth forms a mat of roots or sod • Plants propagate from both seed and rhizomes or stolons • More tolerant of grazing
Legumes • Plants that fix nitrogen from the air • Can reduce the need for nitrogen fertilizers • More growth in the hot summer months than grasses • Watch out for bloat • Need to be inoculated
“How much grass do I have?” Determine forage yield Construct a clipping ring: use an eight foot long piece of cable that has been bolted together.
Forage yield examples If the clipping weight is 200 grams, multiply by 20 for a total available forage yield of 4000 pounds per acre Usable forage – pasture 4000 lbs x 35% (0.35) = 1400 lb/acre Usable forage – “native” pasture 4000 lbs x 25% (0.25) = 1000 lb/acre
Forage availability estimates • Check your pasturelands handout to match hay yield to forage availability. • Clip the grasses for more accurate forage production figures
What are you going to do with your forage? • Graze it! • How long can you graze? • Just long enough that you preserve growing points and leaf area • Then you must rest your pasture
How long do you have to rest your pastures? • Depends upon: • Period in the growing season • Availability of irrigation water • Amount of active leaf area remaining following the grazing period • Cool-season grasses recover more quickly in spring and autumn
Wait a minute! I don’t have grazing animals! • What are you trying to manage? • What are your management goals? • Attract and maintain wildlife • Discourage wildlife • Defensible space • Aesthetics • Noxious weed management
Methods for removing forage • Mowing • Need equipment • Need grass species that grow upright • Be sure to maintain the growing points • Fertilize or add legumes • Leasing to livestock managers for grazing • Need to know your forage yield • Don’t assume management will be good
Burning as a management tool? • Removes rank vegetation, duff, litter • Release mineralized nutrients • Manage some weeds • Regeneration of certain species • Control diseases and insects
Problems with burning • Smoke management • Unhappy neighbors • Requires a permit UNCE, Reno, Nev.
Problems with burning UNCE, Reno • Liability issues – wildfire, etc. • Melts plastic fences • Dust and ash issues • Short-term water quality issues
Remember: love your grass as much as your animals and you’ll all be happy! • Identify what is growing in your pasture(s) • Determine which plant(s) to use as a “key species” for your pasture(s) • Determine the forage yield of your pasture(s)
Homework • Identify three of the most common grass and legume species in each of your pastures. • Select your key species. • Calculate forage yields.