native grass seeding santiago misquez rangeland management specialist nrcs-sw area-socorro,nm...

Native Grass Seeding

Santiago MisquezRangeland Management Specialist

NRCS-SW Area-Socorro,NM575-835-1710

Recognition: Dave Dreesen,PMC

Grass Types Based onPhotosynthetic Pathways

• Cool-season grasses

• Stipeae tribe (needlegrasses and ricegrasses)

• Warm-season grasses

Los Lunas Plant Materials Center

Cool-Season Grasses C-3 photosynthetic pathway

Flowering requires vernalization and/or short days followed by long days

Growth optimum near 70° F (can grow as low as 35° F)

Lower water use efficiency (less DM production/unit water) than C-4 grasses

Long coleoptiles and short mesocotyls (festucoid development) allow adventitious root development near seeding depth

Seeded during summer monsoons or dormant fall planting (expectation of moist soil in early spring)

Dominate in regions where most precipitation falls in cooler months, at higher elevations or latitudes

Los Lunas Plant Materials Center Source: T. A. Jones, 1997

Stipeae Tribe(includes needlegrasses and ricegrasses)

C-3 photosynthetic pathway

Lacks mechanism to store carbohydrates at cool temperatures

Many species do not require vernalization and are photoperiod insensitive

Optimal growth temperatures greater than cool-season species

Found in climates too warm for other cool-season grasses


Warm-Season Grasses

C-4 photosynthetic pathway

May require short days to flower but do not require vernalization

Growth optimum near 90° F with little growth below 60° F

Higher water use efficiencies than C-3 grasses

Mesocotyl elongation (i.e., subcoleoptile internode) forces adventitious roots to develop near soil surface (panicoid development)

Seeded during summer monsoons (late spring before monsoons), generally difficult to establish because of desiccating conditions in the arid SW

Often principal grasses where summer precipitation predominates, at lower elevations and latitudes



Seed

Primary Root System

Seminal Roots

Coleoptile

Adventitious Roots

Mesocotyl (Subcoleoptile Internode)

Warm-Season GrassPanicoid Development

Cool-Season GrassFestucoid Development

Adventitious Root Development Warm- versus Cool-Season Grasses

Seeding Grasses

Seed Depth – Emergence versus moisture

Dormancy – An advantageous trait for seed to persist for later precipitation events or future years

Soil Compaction – Survival is dependent on rapid root extension

Seed to Soil Contact – To facilitate imbibition (absorption of fluid by a solid results in swelling) of soil moisture by seed

Moisture Relations and Soil Texture – Infiltration depth versus water holding capacity

Mulch – Essential step in arid regions to take full advantage of the limited amount of moisture received


Seeding Depth for Optimal Emergence under Ideal Moisture Conditions

• Recommended seeding depths for most native grasses are from ¼ to ½ inch deep

• Some extremely small seed such as many dropseeds (Sporobolus species) and some muhlys (Muhlenbergia species) should be surface broadcast; such small seed will be buried by raindrop impact or during mulch application and crimping

• A few species prefer deep burial including Indian ricegrass


Seeding Grasses and Weed Control

Reduce the weed seed bank in the surface soil by controlling weeds for several years prior to seeding (herbicides, mowing, burning…)

Application of broadleaf herbicides after seedlings are established

Mow weeds in grass sward before annual weeds set viable seed

Do not add nitrogen fertilizer at seeding because weed species will be favored


Mulch Application after Seeding

Native grass hay (some residual seed OK) is the most desirable mulch for large seeding projects

Apply in a layer of sufficient depth to shade soil and reduce wind desiccation, but thin enough to allow seedlings to emerge without restriction (porous hay layer with some soil visible)

Hydromulch wood fiber applied as slurry

Erosion control blankets

Wood or bark chips applied in a thin layer

Gravel mulch (1” deep aids emergence of galleta, 1.5” to 2” prevents emergence)


Mulch Effect on Seedling Establishment – Slender Wheatgrass Broadcast at 50 PLS/ft2

and Sprinkler Irrigated

Treatment Seedlings per Square Foot

Broadcast 3 - 7

Broadcast and raked 10 -11

Broadcast and excelsior mat mulch 28 - 40

Broadcast and hay mulch 31 - 36

Broadcast and bark mulch 34 - 45


Source: M. Majerus, Plant Materials Center, Bridger, MT

Precipitation - “The Master Input”

Seeding success is dependent on sufficient soil moisture following germination to allow seedling establishment

Species having both early and late germinating seed are favored in variable environments

Consistent rainfall for a prolonged period is necessary for warm-season grasses to establish

Survival of first dry period following a biologically significant rain requires seedlings to have

sufficient vigor to survive the subsequent dry period or viable but un-germinated seed remaining after first

wet period


Establishment

Blue grama requires 21 days after germination for adventitious roots to reach a 4-inch depth and the seedling to have 6 leaves and 2 tillers

Adventitious roots arise up to 9 days after germination and reach seminal root depth in approximately 21 days


Frequency Analysis of Size of Precipitation Individual Events or Storms (precipitation on successive days) in the

Northern Chihuahuan Desert from 1915 - 2000

0

5

10

15

20

25

30

5 10 15 20 25 30 35 40 45+

Event or Storm Total (<mm)

Av

era

ge

An

nu

al

Fre

qu

en

cy

EventsStorms

Source: Reynolds et al. 2004


Soil Moisture Distribution in Arid Environments

• Upper 2” to 4” of soil dries out rapidly by evaporation following a precipitation event (little water available for plant uptake)

• Soil moisture in the top 4” to 12” can persist for several weeks

• Moisture under unsaturated conditions at depths below 12” is primarily lost by plant transpiration (no evaporation and no drainage)


“Inverse Texture Effect”

• The depth of wetting is proportional tothe amount of infiltrating precipitationsoil moisture storage capacity

• The storage capacity is 4 to 9% for sands, 11 to 15% for sandy loams, and 17 to 23% for fine-textured soils

• The depth of soil wetting will be greater for coarse-textured soil than for fine-textured soils.

• Coarse-textured soils hold less water per unit depth but much of the water is sufficiently deep to avoid evaporation, whereas in a fine-textured soil most of the water can be lost to evaporation

• Therefore, sandy soils often have more useable soil moisture in arid environments

Los Lunas Plant Materials CenterSource: Noy-Meir 1973

Influence of Soil Texture on Moisture Penetration – One Inch Infiltration Event

and Dry Soil (Wilting Point)

Soil Texture Depth of moisture penetration (inches)

Coarse sand 20

Sand 12

Sandy loam 8

Silt Loam 5


Influence of Soil Texture and Surface Sealing on Average Water Infiltration Rates

(inches/hour)

Soil Texture Minimal Surface Sealing

Moderate Surface Sealing

Coarse sand 0.85 0.50

Fine sand 0.60 0.35

Fine sandy loam

0.45 0.25

Silt loam 0.35 0.20

Clay loam 0.20 0.15

Source: Pair 1983Los Lunas Plant Materials Center

Variables Related to Drying Rate and Grass Seedling Establishment in a Sandy Loam Soil


Drying Rate Slow Moderate Fast

Probability of grass seedling establishment

high low very low

Soil water content 0.4 to 1.2 inches 24% 22% 17%

1.5 to 2.5 24% 18% 8%

3.0 to 4.0 25% 17% 5%

4.5 to 5.5 25% 15% 4%

Total soil water in upper 6 inches of soil

1.4 in 1.1 in 0.5 in

Number of days until drying front exceeds rooting depth

7-8 4 2

Other variables related to drying rate – cumulative precipitation for prior 4 days, air temperature, vapor pressure deficit

Source : Roundy et al. 1997


Patterns of Soil Water Loss over TimeSandy Loam Surface Soil (0.4 to 1.2 inch depth)

0

5

10

15

20

25

30

0 24 48 72 96

Slow

Moderate

Fast

Moderate Gravel

Fast Gravel

PWP

FC

So

il W

ater

Co

nte

nt

(% v

ol.)

Drying Time (hr)

Source : Roundy et al. 1997

Irrigation from Mid-July through August to Enhance Establishment on Abandoned Farmland in the Sonoran

Desert (Supplementing Precipitation of 2.8 inches)

Species Amount of irrigation (inches) required to obtain high density establishment in 1992/1993

Amount of irrigation (inches) required to obtain some establishment in 1992/1993

Purple threeawn 7.4/- 0/-

Cane bluestem 5.3/4.7 0/1.5

Arizona cottontop 5.3/4.7 1.2/1.5

Galleta 7.4/NA 5.3/4.7

Spike dropseed 5.3/NA 1.2/1.5

Catclaw acacia 5.3/4.7

Creosotebush 7.4/5.5

Velvet mesquite 0/1.5

NA – high density not achieved Source: Roundy et al 2001Los Lunas Plant Materials Center

Seed Source Islandsor Resource Islands

• Focus limited resources on small areas• Rely on natural seed dispersal to allow

expansion into outlying areas• Apply intensive resources in a small area to

enhance establishment– Weed control– Supplemental water (rainfall harvesting or minimal

irrigation)– Exclosures to control grazers/browsers (rodents to

elk)– Use transplants of grasses, forbs, and shrubs to

assure establishment and provide immediate diversity


Seeding Rates and Mixes

• 20 to 60 PLS per lineal foot – drilled• 20 to 60 PLS per square foot – broadcast (rates

usually higher because fewer seeds are at optimum soil depth)

• Common usage - 40 PLS per square foot• Total seeding rate for a mix should be 40 to 60

PLS – percentage of each species will depend on desired plant community, vigor of the seedling (competition between species), seed size, PLS seed cost


An Example of a Seed Mix Calculation for a Sandy Arid Site No. of PLS/

Common Name Type Pound PLS Moisture Use Avail.• Indian ricegrass (IR) Stipeae 160k very xeric yes• Black grama (BG) WS 1,300k very xeric maybe• Sand dropseed (SD) WS 5,600k xeric yes• Spike dropseed WS 2,800k xeric ?• Mesa dropseed WS 3,300k very xeric ?• Giant dropseed WS 1,400k very xeric ?

• Mix percentages based on seed and seedling characteristics– IR 25% (large, dormant seed; vigorous seedling; moderate cost per pound)– BG 15% (small seed; low vigor seedling; high cost per pound)– SD 60% (very small seed; low survival; inexpensive)

• PLS rates per square foot – IR 10, BG 6, SD 24• PLS per acre – IR 435k, BG 260k, SD 1,050k• PLS per pound – IR 160k, BG 1,300k, SD 5,600K• Pounds PLS per acre – IR 2.7, BG 0.20, SD 0.19• Hypothetical PLS from seed testing – IR 0.70, BG 0.40, SD 0.85• Bulk pounds per acre – IR 3.9, BG 0.50, SD 0.22


MeanAnnualPrecipitation<88-1010-1212-1414-1616-1818-2020-2424-2832-3636-4040-44


AnnualLakeEvaporation(inches)>8070-79 60-69 50-59 40-49 30-39 <30


NewMexico

AridEcoregions<10 inches

MeanAnnual

Precipitation


Soil Texture TriangleTexture Classes Coarse Intermediate (Loam) Fine


Soil Texture Influences Species Used in Seed Mixes for

Chihuahuan (ch) and Colorado Plateau (cp) Desert (<10” ppt.) Sites Coarse Texture - Sandy

Intermediate Texture - Loam

Fine Texture - Clayey

Indian Ricegrass** Arizona Cottontop** (ch)

> < Galleta**

Sand Dropseed** Bottlebrush Squirreltail**

> < Alkali Sacaton**

Black Grama* (ch) > Bush Muhly (ch) < Tobosa (ch)

Giant Dropseed* >

Desert Needlegrass*

>

Mesa Dropseed (ch)

Sandhill Muhly (cp)


** Likely available* Possibly available

NewMexico

Semi-AridEcoregions

10 - 14 inchesMean

AnnualPrecipitation


Soil Texture Influences Species Used in Seed Mixes for Dry Plains, Sagebrush (sb), and Piñon/Juniper (10-14” ppt.) Sites

Coarse Texture - Sandy



Muttongrass* > < Blue Grama** > < Buffalograss** (not sb)

Needle and Thread* > < Sideoats Grama**

(not sb)

> < Vine Mesquite*

Cane Bluestem**

(not sb)

> < Thickspike Wheatgrass**

< Western Wheatgrass**

Prairie Junegrass* > Bluebunch Wheatgrass* < Curly Mesquite*

(not sb)

Purple Threeawn** > < Green Sprangletop*

(not sb)

Most Desert Species

Most Desert Species Plains Bristlegrass**

(not sb)

< Giant Sacaton*

(not sb)

Most Desert Species

Los Lunas Plant Materials Center ** Likely available* Possibly available

NewMexico

Prairie (High Plains)

Ecoregions>14 inches

MeanAnnual

Precipitation


Soil Texture Influences Species Used in Seed Mixes for Prairie (>14” ppt.) Sites




Letterman Needlegrass*

> < Big Bluestem** < Green Needlegrass*

Sand Bluestem** > Switchgrass** > Some Plains and Montane Species

Plains Lovegrass** > < Little Bluestem**

Sand Lovegrass** < Indiangrass**

Some Plains and Montane Species

Canada Wildrye**

Some Plains and Montane Species



NewMexico

MontaneEcoregions> 16 inches

MeanAnnual

Precipitation


Soil Texture Influences on Species Used in Seed Mixes for Montane Sites




Pine Dropseed* Mountain Brome** > Mat Muhly

Nodding Brome* > Tufted Hairgrass** < Beardless Wildrye**

Spike Muhly** > < Blue Wildrye** < Slender Wheatgrass**

Littleseed Ricegrass

< Sandberg Bluegrass* Some PJ, Plains, and Prairie Species

Fringed Brome* < Arizona Fescue**

Some PJ, Plains, and Prairie Species

Mountain Muhly* >

Deergrass

Some PJ, Plains, and Prairie Species



Soil Texture Influences Species Used in Seed Mixes for Wet Meadow Sites




Common Reed ** > Nuttal Alkaligrass** > < Inland Saltgrass**

Alkali Muhly* > < Knotgrass

Mexican Muhly < (Vine Mesquite)*

Fowl Mannagrass* > < (Beardless Wildrye)**

Meadow Barley** > < Reed Canarygrass **

(Switchgrass)** >

Los Lunas Plant Materials Center** Likely available* Possibly available

Resources

• www.nm.nrcs.usda.gov– Standards/Specs: Critical Area Planting &

Range Planting• http://efotg.nrcs.usda.gov/references/public/NM

• Los Lunas Plant Materials Center 505-865-4684

http://www.nm.nrcs.usda.gov/

http://efotg.nrcs.usda.gov/references/public/NM

native grass seeding santiago misquez rangeland management specialist nrcs-sw area-socorro,nm...

Documents

coolseason grasses c

warmseason grasses c

cool season species

native grasses

principal grasses

surface soil

small seed

mt slide