Lecture 3 Flashcards
Nationally what % of land is reseeded per annum?
2-3%
Regular reseeding tool place on a **% of participants farms, **% reseed in frequently, **% never reseed
(Dairy)
-50%
-25%
-25%
Of those that reseed
-50% of participants reseed **ha/year
-20% reseed **ha/year
-2-4 ha/year
-<2ha/year
**% of participants prioritise reseeding the grazing area
75%
Whats the benefits of reseeding? (2)
-Increased spring/autumn DM production
-Improved sward quality
Whats the preferred time to reseed?
-What % in preferred time?
-What % in other time?
-What % in combination?
Autumn - 66% of survey participants
-13% in spring
-21% combination
On dairy platforms what % of participants soil test area before being reseeded?
-50%
-what % use plough
-what % use minimum cultivation
-what % use a combination of both
-50% plough
-20% use minimum cultivation
-30% use combination of both
When seeding:
-what % use fertiliser spreader
-what % use seed barrow/drill?
-40%
-35%
What % of farms used post emergence spray?
-50%
What % of participants have swards affected by docks?
-85%
Whats docks directly linked to?
Directly linked to low usage of post emergence spray and timing of reseeding
Why do we reseed?
-Because Permanent Grassland is composed to grass inferior to PRG
-Its important to have vigour’s sward as we need grass in early spring and late autumn
Definition: Vigorous Sward:
a sward that can grow out of season, have a high tiller density and provide adequate grass production when required
* Medium term investment = management objectives of the farm
If there is a lot of sward patchy and bare soil on your farm what happens? (2)
1-Productivity decreases due to extra weed grasses
2- Decreased root structure - soil is more easily damages
What is the aim for grass area on your farm?
Thick , leafy sward with plenty of young shoots
– A thin open sward will have a low yield of grass (low DM/h)
– A small % can be tolerated for tetraploid varieties
A thin open sward will have :
Low yield of grass (low DM/ha)
How long does it take silage swards to deteriorate ?
any why?
-Relatively short time
-Because it becomes more open
-Unsown species creep in ( creeping bentgrass/ Yorkshire fog)
What % ryegrass do you aim for?
-How much tonne/DM /Ha/Year vs PP
-How much more responsive is it to available nutrients?
-Losses of us to how much/ha in grass production?
-When is ryegrass less persistent ?
-60%
-+3 tonne DM/Ha/year vs PP
-25% more responsive to available nutrients
-Losses of up to €300/ha grass production
-Less persistent under silage harvesting (5-6 years)
What is detrimental to ryegrass?
-Late harvesting
-Low cutting heights
-Poor soil fertility
Where are grass weeds abundant?
Long term pastures
Are unknown species productive?
Alot less productive than PRG
-Creeping bent has only a **% production potential of PRG
-Whats the DMD ?
-75% Production Potential of PRG
-Lower DMD by 8 units
What is used to control weeds ?
Herbicides- but under certain conditions it may be necessary to reseed a sward
Grass production per month in a sward containing 15% PRG and 100% PRG - what does it show?
-100% PRG has higher tonnes DM/ha
-There is an extra +2.7 tonnes DM/ha
Where do you see benefits of increased % of PRG?
-What happens if pastures have less than 60% PRG?
In February:
-Pastures with less than 60% PRG will not support early or late grazing systems as insufficient grass is being produced.
6 advantages of reseeding :
1- Increased the productivity of swards- with better out of season production
2- Allow a higher level of mid - season regrowth
3-Provide swards which respond better to applied N (25%)***
4-Imporved grass quality
5-Reduce silage requirements
6-Increase carrying capacity
What is the benefits of Grazing newly reseeded sward: (4)
-More grass grown (10-20%) > productive tillers in the seed mix
-Longer growing season
-Rapid re-growth - more productive cultivars
-Higher palatability/digestibility , increased sugar/WSC
What are the benefits of newly reseed sward for silage ? (4)
-Higher quality (6+ units DMD)
-Easier to preserve (higher sugar content)
-Faster recovery
-Consistently higher yields
When and why to reseed?
Early Spring-Autumn
* Low production, regrowth, response to nutrients
* High percentage of open ground
* Low percentage of PRG
* High percentage of undesirable grasses/weeds
* Low percentage of clover
* Change of pasture species (+ other grasses/ legumes/ herbs)
* Part of rotation/ winter forage crops
What are the objectives of reseeding ? (4)
1-Increase the overall productivity of the farm
➢ Increase the carrying capacity (stocking rate)
➢ Allow higher animal output – 8% higher milk output per hectare relative to permanent pasture
➢ Increase grass quality
2-Are more responsive to fertiliser
3-Increase grass utilisation
4-Allow white clover/perennial ryegrass pastures to establish
Whats the target turnout time to get reseed back into production?
Should be 60 days (8-9 weeks)
How long does it take a sward to fully establish?
11 months
Autumn reseeding:
1-What sort of establishment can you get?
2-Degrees for grass seedlings and clover seedlings?
3-What is required for tillering during winter?
4-What can be an issue for Autumn reseeding (2 anwsers)?
1- you can get poor establishment
2- 6 degrees for grass, 8 degrees for clover
3- Early sowing is required for tillering during winter
4-Frit-fly attack
4- There is little-to-no time to apply post emergence herbicides**
1-For Autumn reseeding when is the most suitable month for reseeding?
2-What does reseeding early allow?
3-If clover is included what needs to be done?
4-What is the establishment like?
5-What is the soil temperature threshold like?
1- August
2- Allows seedlings to commence tillering before the onset of winter
3-Reseeding dates needs to be earlier
4-Longer establishment (8-10 vs 4-6 weeks)
5-Higher threshold soil temperature (8 degrees vs 6 degrees)
Whats the advantages of reseeding in spring: (4)
1- Reduced risk of low temps and frost damage
2- Risk of drought and SMD is not a factor
3- Opportunity to graze the sward that helps to promote tillering
4- Application of post emergence spray
Whats the disadvantages to reseeding in spring (3)
1- Increased damaged as cows are reaching peak lactation
2- Large areas of grassland are closed off for silage production
3- Labour
Why do you soil test before reseeding? (5)
1- Shows fertility and pH of soil
2- Correct fertiliser and lime levels
3- Work fertiliser into the seedbed
4- Lime application when not ploughing
5- Developing seedlings are very sensitive to pH
Definition: Soil Fertility
The quality of a soil that enables it to provide nutrients in adequate amounts and in proper balance for the growth of specific plants or crops
List 3 Essential Nutrients in Soil :
1-Phosphorus
2-Potassium
3-Lime
Why is Phosphorus essential ?(2)
1- Essential for root development and sward establishment
2- P is immobile in the soil
Why is Potassium essential? (3)
1- Controls the loss of water by transpiration through the leaf pores
2-Sugar formulation and root development
3-Transport of metabolites and nutrients within the plant
Why is lime essential? (3)
-Optimum pH of 6.3 for grassland
-If pH is low there will be poor establishment
-Trash can release organic acids (OA’s) as it breaks down - inhibit germination
Reseeding methods/ systems:
1- Plough , till, sow
2-Alternatives to conventional: Disking, one-pass, direct drilling
3- Shallow cultivation (Disking) (Disk Harrow)
4- Minimum Cultivation (One-pass)
5- Direct drilling/stitching in /overshowing
What does the Plough , Till, Sow system include:
(Steps)
What is a con of doing this?
- Expensive
- Bury trash, competitors and pests
- Provides the basis for a level sound
seedbed - fine, firm, level - Ploughing may not always be possible
- Shallow ploughing (c.15cm)
- Steps: Spray off old
sward/Plough/Spread Lime/Land
Level/ Spread Fertiliser/One pass
with Seed/Roll
If you are using the conventional Plough, till, sow what steps are involved? (9)
-Involves ploughing
* Old sward is sprayed off – glyphosate
* Can be burnt off before harvesting (10 days)/ grazing (5-7 days)
* Plough <15cm
* Apply lime
* Land level
* Apply fertilizer
* Sow the seed
* Roll > important not to bury seeds***
Whats important about your seedbed?
Needs to be a firm , fine, level seedbed
What are the alternative methods to conventional ? (3)
- Discing
- One pass
- Direct drilling
➢Stitching in
➢Undersowing
➢Oversowing
What can deep cultivation do?
-Bury Nutrients
What is the benefits of shallow cultivation?
keeps nutrients close to the surface <where the developing roots will be
What is the one pass system? for shallow cultivation ?
Whats the Aim?
-2-3 passes of disc harrow in angled directions, land level, lime & fertiliser, one pass with seed, roll
* Aim: produce a fine, firm, level seedbed
What does a firm seedbed do?
Conserves moisture
What does a loose seedbed allow?
Moisture to evaporate easily inhibiting germination