Management tips for drought-stressed forages The forage To Do list - - PowerPoint PPT Presentation

Management tips for drought-stressed forages

The forage ‘To Do’ list………

• Monitor hay and pasture

recovery and growth

• Manage fertility inputs …. thoughtfully
• Consider adding legume seed this spring to grass pastures
• Consider overseeding additional or improved grasses on

the ‘most damaged’, or ‘thinnest’ hay fields and pastures

• Use ‘recovery mode’ in hay and grazing management

Assess general recovery & sod damage

Next Spring………………………….. As an on-going management practice, Evaluate Hay field Stands for winterkill or winter injury

( This is not an exact science !)

Alfalfa - at ‘green-up’ or 2- 4 “ of spring regrowth

• Get an ‘overall view of recovery’
• Check a 1 sq ft site per 5 - 10 A - count plants / sq ft

Age of Stand Good Marginal Expect reduced yield

• ---------plants per square foot -------

Fall of seeding yr 20+ 10-20 < 10 Yr after seeding 12+ 8-12 <8 2 8+ 5-6 <6 3 6+ 4-5 <4 4 & older 4+ 3-4 <3

http://www.ipm.iastate.edu/ipm/icm/1997/4-28-1997/evalalfalfa.html Healthy taproots are creamy-white and firm in texture Determine what % of taproots exhibit crown rot, and the degree of crown rot. Dig all plants in the square foot ………

• - Count plants again !
• - Assess the general condition of plant crowns & taproots

Assess Taproot ‘Health’

Normal Minor Crown Moderate Poor Near-Dead Damage Crown Condition Plant Damage 1 2 3 4 5

If half or more are in categories ‘4’ or ‘5 ….. reduce your ‘plant counts per sq ft by half.

Next Spring………………………….. Evaluate pasture stands

Walk your pastures when they begin to ‘green up’

• - both good and bad areas

Visually determine % of soil covered with desirable forage vegetation Use a ‘better than’ or ‘thinner than’ about 70% cover as an assessment guide.

About 70% Cover

About 30% cover

About 50% Cover

About 80% Cover

If you have about 70% ground cover or greater …. And …….. If fall management and recovery was…….“ Normal” … good fall rainfall good residual leaf area going into winter Plan for “ normal “ spring pasture management

• fertilize
• manage your grazing
• manage weeds

Fertilize pastures in the spring ………..

Phosphorus ( P ) and/or Potassium ( K ) IF they are needed; based on soil testing !! Nitrogen 40 ? 60 ? 80 ? lbs /Ac will stimulate spring growth * * [ N use efficiency is greater if P & K are adequate ] and * If there is sufficient spring soil moisture for good nitrogen response !

If fall recovery was……. Not favorable in fall 2012 …

… limited fall rainfall … pastures grazed close and/or grazed late into the season and Pasture stand density is about 70% ground cover or greater Grass plant may still be under some physiological stress. Fertilize pastures in the spring ……….. Phosphorus ( P ) and/or Potassium ( K ) IF they are needed ; based on a soil test !! Nitrogen 40 ? 60 ? 80 ? lbs /Ac will stimulate spring growth * * [ N use efficiency is greater if P & K are adequate ]

and

* If there is sufficient spring soil moisture for good nitrogen response !

Give recovering pasture stands time to regain ‘vigor’. Pasture plants will benefit from allowing a bit more recovery and growing time in the spring before they are grazed. For best ‘recovery management’ …….

• -- allow 3 - 4 “ of growth in the spring before livestock turnout

And

• -- consider reducing stocking rates by 20 t0 30%

Frost seeding Interseeding No-till renovation

No competition from a dead sod, low potential erosion Keep the existing species But- competition from the sod, less potential for erosion

If you pasture stand density is Less than about 70% ground cover !! ….

• consider oversowing or re-seeding

Don’t’ fertilize with nitrogen (it will just add to the competition from the existing sod !)

• r

Frost seeding

Goal: establish a partial new stand while maintaining the existing sod.

Simple – broadcast seed on pasture in late winter

• r very early spring – when the ground

is still frozen, may have some snow

( See ISU Ext Pub Pm-865 )

Seed on the soil surface is covered by the soil movement during freezing / thawing cycles of late winter and very early spring [ late Feb to early March in Iowa ] Early spring rains also provide some seed covering in bare areas Frostseeding is less successful in dry springs !!!!! Less freeze/thaw coverage in dry soils , & less ‘spring rain coverage !!!

Inoculated legumes are most successful for frostseeding, Red, alsike, ladino clover better than alfalfa & trefoil Grasses - less success with frost seeding …… Orchardgrass > timothy > tall fescue > bromegrass

Best success on sites with exposed bare areas …… in bunchgrass sod (orchardgrass)

• r

into thin sod areas in sod-forming grasses (Kentucky bluegrass, smooth bromegrass) More success when the pasture has been grazed very short ( less competitive !)

• Frequent (but not continuous ! ) grazing early during

the seeding year … reduces sod competition

• Avoid grazing on wet ground --- surface damage
• Graze only on well established sod, do not want to

destroy young sod Other considerations with Frostseeding………

Several important steps that make frost seeding more consistently successful.

• Weeds should be under control - broadleaf

herbicides will kill new legume seedlings ! Fertility – is it good enough for legumes ? Grass sod should be short (less competitive) Moderate, periodic grazing after the pasture sod starts to grow in the spring ….. You want to provide sunlight to new, establishing seedlings !

Interseeding (ISU Ext Pub Pm-1097) :

Goal: establish a partial new stand while maintaining the existing sod.

• Seeding time March through April
• Using drill to place the seeds
• Similar success with legumes and grasses
• But !!! Need more sod suppression with spring

interseeding …… the pasture grasses have already begun to regrow !!!

• - Graze existing sod, in spring, if not already

short

– Continue to graze, rotationally, after

interseeding, with grazing height above the new seedlings

Reduce sod competition !

Or use ‘Chemical’ suppression ?

• contact herbicide, Gramoxone Extra (paraquat) is labeled for this;

Follow herbicide label instructions, and any grazing restrictions !!

• sod must be actively growing for effective contact herbicide use
• periodically graze after interseeding, with grazing height above

the new seedlings … you want to provide sunlight to new, establishing seedlings !

Some considerations when using ‘chemical suppression’;

When you remove grass competition,

annual grassy and broadleaf weeds become more competitive.

And

!!! Suppression herbicides will eliminate much of your ‘spring flush’ of grass !!!!! Factor in the loss of grazing time & forage.

Sod-Seed or Inter-seed

Use no-till pasture drill to seed into existing pasture sod in early spring (March and April)

No-till drills provide: A disk-type or A seed metering A press wheel

• ther sod/ & placement to provide

seedbed mechanism seed-to soil contact

• pener with depth control

Sod-Seed or Inter-seed - continued

As with frost seeding, some management practices improve interseeding success

Weeds should be under control --- broadleaf herbicides will kill new legume seedlings ! Fertility – good enough for legumes ? Grass sod should be short Graze rotationally in the seeding year to allow sunlight availability to establishing seedlings. Seed depth of ¼ to ½ in. with good seed to soil contact Drill inoculated legume seed Consider sod suppression herbicides

No-till renovation (ISU Ext Pub Pm-1097)

• Goal ? Reseed new plant species in killed sod
• r crop residue of previous grain crop
• Chemical, (glyphosate; Round-Up) burn-down

may be needed – For existing old sod fields, you need to wait until you have ~4-6”

• f grass growth for the glyphosate to be most effective …..

this leads to relatively late spring planting – Don’t delay too long; it is harder to establish seedlings if hot and dry late-spring conditions develop

• Use similar seeding rates as interseeding
• Use similar no-till drill practices as when interseeding

Some other related ISU Ext Publications Pm-1792. Selecting Forage Species

http://www.extension.iastate.edu/Publications/PM1792.pdf

Pm-865 Improving Pasture by Frost Seeding

http://www.extension.iastate.edu/Publications/PM856.pdf

Pm-1097 Interseeding and No-till Pasture Renovation

http://www.extension.iastate.edu/Publications/PM1097.pdf