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Pasture Renovation and Improvement

Stephen K. BarnhartExtension Agronomist –ForagesIowa State University Extension

Ames, Iowa 50011-1010Phone 515-294-7835

Email sbarnhar@iastate.edu

Evaluate your Pasture ?Evaluate your Pasture ?

This can range from:This can range from:

Simply observing that Simply observing that ““ ItIt’’s still green out theres still green out there””

Sophisticated assessment of:Sophisticated assessment of:-- plant species diversityplant species diversity-- plant / tiller densityplant / tiller density-- amount of DM / inch of pasture heightamount of DM / inch of pasture height

From USDAFrom USDA--NRCSNRCS

‘‘Pasture conditionPasture condition’’ scoring focuses scoring focuses on:on:

Vegetation traitsVegetation traitsDiversity, desirability, % legumes, Diversity, desirability, % legumes, ‘‘vigorvigor’’plant cover, uniformity of use, severity ofplant cover, uniformity of use, severity ofuse, tree/shrub canopy coveruse, tree/shrub canopy cover

Site / Soil traits Site / Soil traits active erosion ?, degree of plant residueactive erosion ?, degree of plant residue

ManagementManagementcompaction, fertility insects & diseasescompaction, fertility insects & diseases

10 factors 010 factors 0--4 ranking for each 4 ranking for each -- -- high score 40high score 40

Of what value is pasture condition scoring ?

It’s a ‘snapshot in time’

It forces a detailed look at important pastureand grazing factors

It gives guidance for immediate or futuremanagement changes

A problem often associated withnon-uniform pasture production is a mis-match between forage needs and for availability.

SupplySupplyNeedsNeeds

Approximate Approximate ‘‘seasonseason--longlong’’ pasture needs per pasture needs per average sized beef cow, with pasture providing average sized beef cow, with pasture providing most, if not all, of the nutrition :most, if not all, of the nutrition :1 1 -- 2 Ac. Excellent, dense sod,2 Ac. Excellent, dense sod,

permanent pasture permanent pasture

Note ! Supplement hay etc. when neededNote ! Supplement hay etc. when needed

2 2 ––2 2 ½½ Ac. Ac. ‘‘AverageAverage’’ permanent pasturepermanent pasture(This will have spring excess(This will have spring excessOK summer forage in ave.OK summer forage in ave.years.)years.)

3+ Acres 3+ Acres ‘‘thinthin’’, poor sod, unmanaged, poor sod, unmanaged(Supplemental forage will(Supplemental forage willlikely be needed !!!)likely be needed !!!)

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J F M A M J J A S O N D

We are often challenged with with the We are often challenged with with the ‘‘roller coasterroller coaster’’ growth pattern of our growth pattern of our ‘‘coolcool--seasonseason’’ grassgrass--based pastures ! based pastures !

A more productiveCool-Season grass‘Bromegrass’‘Orchardgrass’doesn’t solvethe problem

Ky Ky bluegrassbluegrass

Adding Nitrogen to grass pastures ?Adding Nitrogen to grass pastures ?

Grass responds to N more than anyGrass responds to N more than anyother fertilizer nutrient !other fertilizer nutrient !

Simply produces moregrass when there is already a surplus !

J F M A M J J A S O N D

Ky Ky bluegrassbluegrass

Adding a Adding a ‘‘warmwarm--season grass pasture season grass pasture to compliment the coolto compliment the cool--season season grass pastures ?grass pastures ?

Annual or Perennial

J F M A M J J A S O N D

Ky Ky bluegrassbluegrass

SudangrassMilletsSwitchgrassBig bluestem Etc.

J F M A M J J A S O N D

Other forages are productive during Other forages are productive during Other parts of the growing season Other parts of the growing season

Ky Ky bluegrassbluegrass

Add a Legume *

Two pasture condition scenarios :Two pasture condition scenarios :

‘‘Spot grazingSpot grazing’’ ––selective grazingselective grazing

Animals in Animals in ‘‘good good conditioncondition’’

Significant areas Significant areas avoided, matureavoided, maturegrasses (headed)grasses (headed)

Weeds invadingWeeds invading

More pasture than animal powerMore pasture than animal power’’

Another scenario; the other extreme :Another scenario; the other extreme :More animals than pastureMore animals than pasture

Can Can ‘‘keep upkeep up’’ with Spring growth (maybe)with Spring growth (maybe)Short pasture summer, fall (winter ?)Short pasture summer, fall (winter ?)Need to feed supplement hay / feedNeed to feed supplement hay / feedWeeds invadingWeeds invadingThin sod, and active erosion areasThin sod, and active erosion areas

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Management Management ‘‘FixesFixes’’ for the two scenarios.for the two scenarios.

11stst Scenario (excess pasture)Scenario (excess pasture)

-- add animals add animals

-- reduce grazed areareduce grazed area

-- clip seedheads and weeds, keep clip seedheads and weeds, keep a surplus situationa surplus situation

-- harvest excess as hayharvest excess as hay

22ndnd Scenario (Scenario (““over stockedover stocked””))

-- reduce animal numbers !!!reduce animal numbers !!!

-- boost production of the pastureboost production of the pasture

-- supplement some of daily needs assupplement some of daily needs ashay or feedhay or feed

-- implement rest / rotation grazingimplement rest / rotation grazing

-- manage weeds manage weeds ( animals will begin to ( animals will begin to ‘‘testtest’’

less desirable plants )less desirable plants )

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*Animal Unit Factor*Animal Unit Factor

1 AUM [animal unit month] =1 AUM [animal unit month] =Forage energy needs of a 1000# beef cow & calf for 1 monForage energy needs of a 1000# beef cow & calf for 1 monthth

~ 28 lbs DM per day or ~ 850 lbs DM per month~ 28 lbs DM per day or ~ 850 lbs DM per month

Seasonal pasture productivity – by month

Project forage needed & supplied – by monthAdjusting animal numbers gets a bit more Adjusting animal numbers gets a bit more tricky as pasture sizes get smaller.tricky as pasture sizes get smaller.

+ 1 animal overstocked situation+ 1 animal overstocked situation

-- 1 animal less efficient use 1 animal less efficient use ( but better for the animals( but better for the animals

and the pasture ! )and the pasture ! )

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What can fertilization do ?Reed CanarygrassTall FescueSmooth BromegrassOrchardgrass

GrundyClarindaWellerKeswick

Ky bluegrass

Early spring 60-80 lbs/A

Late spring (Optional) extra 30-40 lbs/A

& / or Late Summer (Optional) extra 30-40 lbs/A

Orchardgrass

Tall, Cool-Season Grasses

Early spring 80-120 lbs/A

Late Spring (Optional) extra 40-60 lbs/A

& / or L- Summer (Optional) extra 40-60 lbs/A

Legume-Grass Mixed Pastures If more than 1/3 legume –

*Note for Legume-Grass Mixed Pastures:

High & frequent Spring applications of nitrogenleads to grass dominance and less legumes.

Consider deferring N applications until late summer or fall

no nitrogen is recommended

If less than 1/3 legume –treat as a grass pasture

These mixed pastures with will respond more to P and K.These mixed pastures with will respond more to P and K.

Phosphorus (P), Potassium (K) and Lime

Needs and rate are determined by a soil test !

Existing pasture

For P & K Sample to a 6 inch depth

For Lime RecSample to 2 to 3 inches

New seeding or re-seeding

Sample to ‘Tillage Depth’

Why is Lime recommended ?The soil ‘acidity’ (pH) influences the availability of fertilizer nutrients and soil microbial activity.

Lime is used to raise a low soil pH (acid condition)

pH for Forage Crops `Target pH’ Don't Worry’

Alfalfa 6.8 - 7.0 6.5 - 7.5Clover & BFT 6.5 - 7.0 6.0 - 7.5Forage Grass 6.0 - 7.0 5.7 - 7.5

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Phosphorus (P), Potassium (K)

P & K needs and rate are determined by a soil test !

Yield responses to phosphorus (P) and potassium (K) are not dramatic nor consistent.

Forage plants will respond to added (P) and (K) when .

‘Optimum’ ‘Optimum‘

Low Very Low

Not palatable

Canada Thistle Bull Thistle Plumeless ThistleMusk Thistle

Manage Pasture WeedsLivestock eat some of those pasture weeds !!!

Blue vervain Horse nettle Buffalo bur

Giant ragweed Goldenrod Burdock

Less palatable

Downy brome Squirreltail barleyFoxtail barley

Little barley

Pasture weed control –cont.

Cultural Weed Management

Establish & maintain thick grass stands of grasses and legumes that are adapted to your climate and site.

Use proper fertilization

Use proper grazing management

‘Mechanical’ ManagementClip, mow or dig :

1) prevent new seed production2) minimize effect of competition on pasture

(mowing is not very effective for low-growing weeds ! --- spray will be better for these.)

Spray Management

Most pasture herbicides are to control ‘broadleaf’weeds and keep the grasses -- !! Kills legumes !!

Timeliness is important- weed become harder to kill when

they are mature

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Biennial weeds (bull thistle, plumeless thistle, musk thistle)

1st growing seasonDig; or Spray in the fall while the weed

is still in the ‘rosette' stage

2nd growing season the biennial weed will ‘bolt’ (shoot a seed stem, and die)

Spraying during this growth stage is less effective

Perennial weeds (Canada thistle, vervain,multiflora rose)

(can grow for many years, reproduce by seed & roots )

1) Mow 2) spray during vegetative growth stage;

-- ‘more active’ herbicides are normally used -- systemic herbicides very useful

3) multiple treatments needed to “starve-out”the plant

Extreme situations -may have to kill the grass too !

Grazing Management Grazing Management

A successful way to maintain andA successful way to maintain andimprove pasture productivity is toimprove pasture productivity is toimprove grazing managementimprove grazing management. .

If given the choice, animals will return to a previously grazed area (spot grazing),ignoring taller, more mature forage.

This lead to ‘over grazing’ of some areas.

IT REQUIERS SOME REST FOR THEIT REQUIERS SOME REST FOR THE

Plants !!!! Plants !!!!

After a grazing (defoliation), After a grazing (defoliation), a plant needs to a plant needs to ‘‘mobilizemobilize’’its stored sugars, proteins, its stored sugars, proteins, and growing points to and growing points to establish new leaf area.establish new leaf area.

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Rest can be created by dividing Rest can be created by dividing the pasture into smaller grazing the pasture into smaller grazing areas. areas.

-- This may not be very practical for mall acreages !This may not be very practical for mall acreages !

-- Includes issues associated withIncludes issues associated with……....

fencing, water, building access, feeding etc. fencing, water, building access, feeding etc.

How much ‘improvement’ from rotational grazing ?

Depends upon where you start !

‘Abusive’, continuous grazing

8 to 10+ paddocks 10 to 20 % more * 25 to 35+ % total *

3 to 4 paddocks 10 to 15 % improvement *

* Assumes appropriate stocking rates And good day to day management

‘Patching’, ‘Thickening’ and Replacing Pasture

Assess whether what you have now is worth keeping.

Add more or more productive grasses

Add legumes

Start over !

Frost SeedingFrost Seeding

Simple Simple –– broadcast seed on pasture in late broadcast seed on pasture in late winter / very early spring (latewinter / very early spring (late--February through March) February through March)

Frost SeedingFrost Seeding -- continuedcontinued

There are several other important steps thatThere are several other important steps thatmake frost seeding more consistently make frost seeding more consistently successful. successful.

Weeds should be under control Weeds should be under control

Fertility Fertility –– good enough for legumes ?good enough for legumes ?

Grass sod should be shortGrass sod should be short

Graze seeding year to allow Graze seeding year to allow establishmentestablishment

Graze later years to keep new plants !!!!!Graze later years to keep new plants !!!!!

SodSod--Seed or InterSeed or Inter--seedseedUse noUse no--till pasture drill to seed into till pasture drill to seed into existing pasture sod in early spring existing pasture sod in early spring (March and April)(March and April)

No-till drills provide:

A disk-type or other sod/seedbed opener

A seed metering and placement mechanism

A press wheel to provide For seed-to-soil contact

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SodSod--Seed or InterSeed or Inter--seedseed

Most interseeding is done in early Most interseeding is done in early spring (March and April) spring (March and April)

Consider late summer (Aug thru very Consider late summer (Aug thru very early Sept) early Sept) IF soil moisture is adequatesoil moisture is adequate

Some county conservation agencies rent these

SodSod--Seed or InterSeed or Inter--seed seed -- continuedcontinued

As with frost seeding, some management As with frost seeding, some management practices improve interseeding successpractices improve interseeding success

Weeds should be under control Weeds should be under control

Fertility Fertility –– good enough for legumes ?good enough for legumes ?

Grass sod should be shortGrass sod should be short

Graze seeding year to allow establishmentGraze seeding year to allow establishment

Graze later years to keep new plants !!!!!Graze later years to keep new plants !!!!!

Drill seed to a depth of ¼ to ½ in. and cover

Consider sod suppression herbicides

Types of ‘Seedbeds’

Reduced tillage Conventional tillage

Tilled seedbed

Mostly fine, withsome pea tomarble sized clods

Firm enough –

That you don’t sink in any deeper than the sole of your shoe, or the tread ofa pick-up truck tire

Excellent Seeding Technique

Uniform distribution of seed acrossthe seeded area

Uniform final depth of placement 1//4-1/2 inch (after all equip. passes)

Excellent seed – to – soil - contact

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No-Till forage planting

Into Killed sodCrop residues

Other establishmentprinciples apply !!!

‘Native’ wm-season grasses

Truax (native grass drill)

appropriate ‘seed metering’mechanism