Seeding and Establishing Salt-Tolerant Plant Species

Karin Lindquist, BSc Ag

Forage Establishment for

Saline Areas

• Salt Tolerance: Ability of plants to grow and withstand moderate to high salt concentrations on leaves, in water, or in soil within root-reach, without significant adverse effects. o Various species to consider

• Tame Legumes & Grasses

• Native Grasses

o Where you can purchase seed

o Forage establishment & seeding considerations

• Seed mixes & their options o Seed mix percent vs. plant establishment percent

• Management considerations

• Seeding forages

Salt Tolerant Plants

• Salt-tolerance o Ranked from moderate, high and very high

• Tame or Native o Sod or bunch

o Reclamation, tame pastures, or hay

• Longevity

• Rate of Establishment

• Persistence

• Winter hardiness

• Flood tolerance

• Drought tolerance

• Livestock palatability

When Considering “What Species?”

Salt Tolerance Variability

Munns & Tester (2008)

• Very High Saline areas: o Red Samphire (Salicornia europaea)

o Sea Blight (Suaeda calceoformis)

• High Saline areas: o Foxtail Barley (Hordeum jubatum)

o Kochia (Kochia scoparia)

Weeds are Good Indicators…

Red Samphire

Sea Blight

Kochia Foxtail Barley

• Majority of alfalfa cultivars/varieties, even those recommended for saline areas, are only moderately salt-tolerant.

• Alfalfa is not flood tolerant

• Soil pH can also negatively affect alfalfa stands o Lower pH (acidic) reduces yield and seed establishment

• Best recommended cultivars:

o Spredor 5 & Halo (CPS)

o Assalt ST (Pickseed)

o Barricade SLT (Brett Young) • Spredor 5 ideal for both pasture and hay; Halo best for hay only

o Spredor 5 winter hardy, drought tolerant, persistent stands; creeping-rooted

• Halo less of any of these, except pest resistance

• Assalt ST and Barricade SLT adapted for saline and alkaline soils

Alfalfa (Medicago sativa)

• Moderate to possibly low salt-tolerance

o Norgold Yellow Blossom Sweet Clover

o Yellow Blossom Sweet Clover • Both have great drought tolerance

• Grazing and Hay production recommended in moderation

o Concerns with lowered palatability in mature stands • Bitter-tasting plants

• Good palatability with immature plants (not yet flowering)

o Moldy feed creating sweet clover poisoning via dicoumoral

Sweet Clover (Melilotus spp.)

• Tall Fescue (Festuca arundinacea)

o Suitable for both pasture & hay.

o Persistent, winter hardy, good flood & drought tolerant. Long-lived.

o Varieties:

• Barlox & hps® (CPS)

o Barlox with stronger salt tolerance

• Carnival (Pickseed)

• Riding Brand/Cowgirl (Brett Young)

• Tall Wheatgrass (Thinopyrum ponticum)

o Moderately good for pasture and hay

o Good drought & winter hardiness, persistent stands

Tame Grasses

• Russian & Dahurian Wildrye (Elymus junceus & dahuricus)

o Pasture & hay; very slow to establish; bunch grasses.

o Russian more winter hardy, drought tolerant, and persistent

o Dahurian much better flood tolerance

• Considered an annual (not Russian)

• Altai Wildrye (Elymus angustus)

o Very slow establishment, highly persistent once established, bunch grass.

o As winter hardy & drought tolerant as RWR; moderate flood tolerance

Tame Grasses

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Green Wheatgrass AC Saltlander (Thinopyrum intermedium)

high sod average long moderate high moderate high good

Slender wheatgrass (Elymus trachycaulus)

moderate to high

bunch very fast short moderate high moderate moderate fair

Western Wheatgrass (Pascopyrum smithii)

moderate to high

sod fast long high high high high good

Northern Wheatgrass (Agropyron dasystachyum)

moderate to high

sod fast long high high high high good

Alkali Cord Grass (Spartina gracilis)

high sod fast long moderate moderate moderate high low

Sand Dropseed (Sporobolus cryptandrus)

moderate bunch fast long low high moderate low low

Native Grasses

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Nuttall’s Alkali Grass (Puccinellia nuttalliana)

very high sod average long moderate high moderate high good

Beardless Wildrye (Leymus triticoides)

very high sod very slow long moderate high high high fair

Saltgrass (Distichlis

stricta)

very high sod average long low high moderate high fair

Blue Grama (Bouteloua gracilis)

moderate sod average long low high moderate high good

Narrow-leaved Reedgrass (Calamagrostis stricta)

moderate sod fast long high low moderate moderate fair

Mountain Brome (Bromus carnistus)

moderate sod average long low moderate moderate low good

Sloughgrass (Beckmannia syzigachne)

moderate sod average long moderate low moderate moderate low

Native Grasses

>>Do not buy any type of seed and expect it to “do well” in your area.<<

• Know what “natural region” your operation is in! o Aspen Parkland vs. Dry Mixed Boreal

o Foothills Fescue Grassland vs. Moist Mixedgrass Prairie

• Location on the landscape o North versus south side of the hill (for knob-and-kettle

landscapes)

o Dry or “xeric” areas or moist (“mesic” to “subhygric”) locations? • Water table level, is area possibly prone to flooding or no?

• Soil quality/fertility/type o Dark Brown or Brown Chernozems, Grey-Wooded (Grey or

Dark-Grey Luvisols), Black Chernozems? • What is pH? Clay, sand, loam content? What about organic

matter (SOM)?

Cautions With Purchasing Native Seed

• Brett Young

o Calmar/Leduc

o Rycroft

• Northstar Seed Ltd.

o Calgary

• Hannas Seeds

o Lacombe

• SeCan o seed@secan.com

o Ontario head office

• Crop Production Services (CPS) Canada Inc. o Torrington

o Red Deer

o Crossfield

o Threehills

o Delburne

o Stettler

o Trochu

• Pickseed o Products sold thru UFA

o Head office in Edmonton

Where to Look & Buy

• Various options to choose from o See your local seed supplier for information

• They will have recommended mixes in stock, or make custom mixes for you

o Mixes based on what forages you want, how quickly they establish, how prolific and persistent they are, whether you are going to use them for hay or pasture, etc.

o Percent mix in the bag has nothing to do with how many plants that will come up after seeding

• x % species variety only shows how much percent weight of seed is in the bag!

• Quiz Q: What percent plants will come up with a 80% Alfalfa 20% Timothy mix? o The Answer may surprise you!

Forage Mixes

• What percent plants will come up with a 80% Alfalfa 20% Timothy mix?

o Hint: Look at # of seeds per pound! • Alfalfa: 200,000 seeds/lb (!)

• Timothy: 1,230,000 seeds/lb (!!)

o Rough calculations:

• 80% Alfalfa = 8 lb/acre seeded alfalfa

o 8 lb/acre x 200,000 seeds/lb = 1,600,000 seeds/acre

• (1,600,000 seeds/acre)/ 43,560 ft/acre = 36.7 seeds/ft2

• 20% Timothy = 2 lb/acre seeded

o 2 lb/acre x 1,230,000 seeds/lb = 2,460,000 seeds/acre

• (2,460,000 seeds/acre)/ 43,560 ft/acre = 56.5 seeds/ft2

% Seed Mix ≠ % Plant Emergence

• Assuming 50% death loss…

o For Alfalfa: 36.73 / 2 = 18.37 = ~18 plants/ft2 emerge • Translated: 18.37 / (18.37 + 28.24) * 100 = 39.41% or 39% Alfalfa in the stand

o For Timothy: 56.47 / 2 = 28.24 = ~28 plants/ft2 emerge • Translated: 28.24 / (18.37 + 28.24) * 100 = 60.59% or 61% Timothy in the stand

• More calculations to do for *higher* mixtures (more forage species) but, the concepts of % seed mix vs. % plant emergence is the same. o Take Home Message: NEVER expect the same percent of plants coming up in a stand as

the percent advertised on the seed bag!

% Plant Emergence Calculations…

• Use a mix with saline areas (highly recommended!)

o Quite variable salinity levels; seeding down species with varying salinity tolerances and life spans advantageous • Slender wheatgrass best sown with other species. Short lifespan = 2 or 3 yrs, will

start to die out once other species have established.

o Most mixes include alfalfa. Alfalfa may only establish at edges because of moderate salt tolerance

o Other grasses like AC Saltlander, Tall Wheatgrass, Tall Fescue, Russian Wildrye, Saltgrass, etc. will take over centre of saline areas and choke out weeds (foxtail barley)

o Must include flood-tolerant species.

Management Considerations

• The Dilemma: For Hay or Pasture? Or Both? o Mixes for hay: Utilize species that can be harvested easily.

• Dahurian Wildrye; Alfalfa; Tall Fescue; Tall, Green, Western Wheatgrasses

• Avoid low-growing or basal growing grasses (Northern Wheatgrass and Russian Wildrye)

o Mixes for Pasture: More flexibility than hay.

• Can use tall-growing and low-growing forages, and those ideal for fall/winter grazing.

• Some degree of flood tolerance recommended o Most saline areas in Alberta are prone to water saturation come spring (low-lying

depressions or “seeps”)

• Deep-rooted plants advantageous o Draw down soil water levels Reduce upward movement of salts

o Alfalfa and native grass species excellent choice for this

Management Considerations

• Salt content of soils can wreak havoc on seed viability! o Death loss can be much higher than predicted average 50% for non-saline

areas • Species with moderate or low salt tolerance seeded into high to very high saline areas

will simply not grow (death loss = 100%). o Alfalfa; Barley; Timothy; Reed Canary Grass; Smooth Brome; …

o Salts in soil draws out water from the seed’s endosperm • Just like what happens when a “non-salt tolerant” plant is put into salt water.

• Salt-tolerant plants with compounds to offset unfavourable osmotic conditions will grow o Performance and vigour unhampered, especially with high to very high salt-tolerant

species

o **Must plant at twice the seeding rate in saline depressions as for non-saline areas to increase chance of seed emergence**

Management Considerations

• Fertilizing: Yes, especially if your soil test results say so. o Typically saline areas are lacking in available nitrogen and phosphorus

o Higher yields and greater competition with weeds go hand-in-hand with forages that get their fertilization requirements met.

• Take soil samples! o Several 15 to 20 samples @ 0 to 6 inches (and 6 to 12 inches, if necessary) around saline

area and to 200 ft out from salt line. Bag up immediately and keep in a cool place.

• Mix samples (keep 0-6” and 6-12” depths separate); Subsample (if necessary), Bag, & Label (farm name, which field, what depth, date), and Ship to soil lab:

o Exova Canada Ltd. (Calgary & Edmonton)

o Down to Earth Labs Inc. (Lethbridge)

o IEH Services Canada (Brooks)

• Results should yield N, P, K, S (and other micronutrients) levels, EC (electrical conductivity), organic matter, soil type (amount of clay, sand & loam), and other potential issues.

Management Considerations

• Seed down in fall (just before freeze-up) if fields are too wet in spring o Legumes *should* be seeded in spring or early summer only

for successful winter survival, but...

• It’s no use trying to seed in wet areas in springtime if you’re going to get stuck!!

o High moisture in spring pulls down salt levels in rooting zone, increasing germination and plant establishment success.

• When seeding around saline sloughs or depressional seeps, plant around the wetlands. o Cover both the visible salt line, and extend an additional 20

to 60 m (65 to ~200 ft) further out.

When & Where to Seed?

• Suppress weeds with non-selective herbicide before and/or after seeding • If after seeding, do so before seedling emergence (i.e., less than a week after seeding)

• May also spray the year before, at post-harvest or during the summer or late spring • Spraying earlier may give the plants a chance to decompose

• Risk of weed re-emergence if sprayed too early

• In pasture or hay stand: Graze area as heavy & hard as you dare. • Graze off 75% of stand.

• If necessary, treat with herbicide after animals are removed as well.

• Pack it down. o Forages require seeding depth no more than ¾” (1.9 cm).

o Pack down so that you can only see your toe and heel, not the arch in between (work boots only, not with sneakers!) = ¼” (0.65 cm)

• Or, so that tractor tires can barely be seen (especially in existing sod or stubble fields)

• More difficulty packing sandy soils than clay. o But, you can seed a little deeper in sandy soils because plants don’t have as much matter to

push through to the surface.

How to Prepare Seedbed?

• Seed twice the recommended amount for non-saline areas. o If bag recommends seeding 13 lb per acre, seed at 26 lb/acre.

o If custom mix of forages recommend various seeding rates for those forages, double those recommended rates for saline areas • Need more seed… and more bags of seed…

• No-till recommended if sowing into existing forage stand or crop stubble o Disc or narrow knife openers with cutting coulters best. How openers simply tear up the

surface. • With packer following behind, in-row packing ensures slot is sealed and seeds covered with

soil

o Minimal loss of soil moisture as a result.

• Broadcast seeders may also be used o If seed drills cannot be used

o Inaccuracy with equipment, especially if spreading mixes with unequal seed size

How to Seed?

• Legumes may need deeper seed depth than grasses o Smaller seeds should only be seeded at ¼” instead of ½” to ¾” deep.

o With mixes, may need to reach a “happy medium” to provide an optimum depth for all mixes • Suggest ½” at most if you have small seeded forages like Sand Dropseed or Calamagrostis

(Reedgrass).

• Forages with arger seeds like with Wildrye and Wheatgrasses (have less seeds/lb than Calamagrostis or Dropseed), safe to go a little deeper.

• Row spacing: Remember, you are in competition with highly prolific weeds. o Greater spacing may, ideally, increase forage biomass, but…

o You can be asking for trouble too with allowing weeds to come in more readily between rows!! • Kochia and foxtail barley are very prolific weeds that have great potential to out-compete

newly seeded forages!!

o About ~6” to 9” row spacing sufficient for establishing forages in saline areas.

Seeding Considerations

• Spray with Herbicides Post-seeding? o Not unless you sprayed with a pre-emergence herbicide

o Herbicide treatment may target weeds, but

• May also hit forage species and kill them out too. Not good!

• Other post-seeding management options: o If weeds are getting out of hand, out-competing forages, mow them

• Mowing or swathing just above the forage seedling height opens canopy

o Allows forage seedlings to take over and smother out weed stands

• Swath, and bale up ASAP, and remove bales as quickly.

o Leaving swaths in the fields will smother the forage seedlings.

o Bales? Feed them to your animals.

Seedling Establishment