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  Plant identification  Determining forage yield

How plants make food for growth

What plants are growing in my pasture?  Legumes  Grasses  Weeds (we’ll talk about them later) UNCE, Reno, Nev.

Legumes

Parts of a legume taproot leaflet flower stem leaf stolon A. Miller

How legumes grow  Vegetative growth  Bud stage  Flowering NCSU

Grasses

NRCS, Bozeman, Mont. 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.

OSU Penn State Univ. 2 tillers developing from the crown of the plant A joint (node)

NRCS, Bozeman, Mont. 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

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

 Grass plants reproduce by forming seed heads  Some plants also reproduce by sending out spreading roots or shoots Plant reproduction USDA NRCS UNCE, Reno, Nev.

Long-shoot phase of growth (elongated internodes) Short-shoot phase of growth Growing points removed; must regrow from basal buds Regrowth Growing point level Intact growing points

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 Kentucky bluegrass rhizome Penn State Univ.

Adapted from NRCS by A. Miller

Adapted from NRCS, Bozeman, Mont.

Adapted from NRCS, Bozeman, Mont. by A. Miller Take half and leave half

UNCE, Reno, Nev.

Nutrient content by plant growth stage A B C Adapted from by A. Miller

 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 Managing for productivity

Identifying grasses UNCE, Reno, Nev.

Plant life cycles  Annual  Biennial  Perennial OSU

Cool-season plants  Optimum temperature range 65 to 75 degrees F  Productive in spring and fall  Reduced growth in summer  Higher in crude protein  Respond to nitrogen fertilizer  Orchardgrass, fescues, perennial ryegrass and bromes are examples

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 are big and little bluestem, switchgrass, Indiangrass, and sudangrass

Cool-season versus warm-season grass productivity A. Miller

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

Tall fescue Forage and Grass Curriculum

Orchardgrass

Perennial ryegrass

Annual ryegrass

Timothy

Crested wheatgrass National Park Service

Siberian wheatgrass APMC, Idaho

Tall wheatgrass

Intermediate wheatgrass

Pubescent wheatgrass NRCS, Bozeman, Mont.

Slender wheatgrass USDA Plant Gallery

Basin wildrye plants.usda.gov Aberdeen Plant Materials Center, Idaho.

Russian wildrye prairiewild.com

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

Kentucky bluegrass

Brome, annual species  Soft chess / Blando brome  Japanese brome  Red brome  Undesirable species  Ripgut  Cheatgrass

Soft chess / Blando brome elib.cs.berkeley.edu

Japanese brome incolor.inebraska.com

Meadow brome

Red brome Burke Museum of Natural History

Smooth brome UNCE, Reno, Nev.

Garrison creeping foxtail agronomy.unl.edu

Meadow foxtail

Quackgrass

Reed canarygrass

Streambank wheatgrass

Thickspike wheatgrass NRCS Plant Database

Western wheatgrass USDA Plant Gallery Kansas Grasses

Warm-season bunchgrasses  Growth occurs late spring to early summer  Growth occurs in clumps  Plants propagate by seed only  Grazing needs to be managed correctly so that seed heads do not form too early

Alkali sacaton

Big bluestem National Forage and Grasslands Curriculum

Little bluestem

Sideoats grama

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

Indiangrass

Switchgrass

Sudangrass National Forage and Grasslands Curriculum

Sorghum-Sudangrass hybrids

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

Bloat Laurie Ball-Gisch

Alfalfa

Birdsfoot trefoil UIUC

Alsike clover Burke Museum

Red clover

Strawberry clover clay.agr.okstate.edu

Subterranean clovers elib.cs.berkeley.edu

White clover

Yellow and white sweetclover

Sainfoin clay.agr.okstate.edu

Cicer milkvetch extension.agron.iastate.edu

Common vetch (also called spring vetch) National Forage and Grasslands Curriculum

Grass identification – it’s time to try your skills!

How much grass do I have?

Determine forage yield Construct a clipping ring using an eight foot long piece of cable that has been bolted together.

NRCS, Bozeman, Mont.

General estimates for determining forage yield Usable forage in reasonably good condition pasture = 35% of total forage Usable forage in “native” pasture or rangeland = 25% of total forage

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

Approximate grazing length and regrowth periods SeasonGrazing lengthRegrowth period Spring4 – 5 days10 – 14 days Summer9 – 10 days21 – 30 days Late summer 12 – 15 days30 – 45 days

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

What about 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  Liability issues – wildfire, etc.  Melts plastic fences  Dust and ash issues  Short-term water quality issues UNCE, Reno, Nev.

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.