W4 -L2 - Crop Establishment and Seedbed Preparation Flashcards
what can vary the yield potential of cereals crops
vary across soil types
what will happen when soils have good yield potential
Soils with ‘good’ yield potential will produce that yield if management, inputs and climate are optimal
what will happen when soils have poor yield potential
Soils with ‘poor’ yield potential will have a limit to yield irrespective of the level of management, inputs and nature of the climate
pH of soils for :
Wheat:
Oats:
Barley:
Wheat: 6.0+ is best (problems if <5.4)
Oats: 4.7-6.0 (optimum)
Barley: 6.2-6.5 (problems <6.0)
soil type/ texture for:
Wheat:
Oats:
Barley:
Wheat: medium- heavy - good % clay
Oats: medium- heavy - lodging risk
Barley: light-medium - well drained
Objectives of Cultivations (6)
- germination
- facilitate root development
- aid drainage
- control weeds
- bury thrash
- control pests
definition of conventional tillage
Intensive primary soil inversion to 200 -300mm followed by intensive secondary tillage and subsequent seeding
def of direct drilling
seed placement without tillage.
in between conventional tillage and direct drilling
A complete range of systems: Deep or shallow reduced tillage, Strip tillage etc.
what is an excellent method of crop establishment
plough - till - sow
what the key component of crop establishment
good ploughing
describe ploughing
- inversion of the soil (20-25cm depth)
- loosening of the soil layer
- consolidation of the ‘new’ surface
- burying of the previous crop trash
what are the advantages of ploughing (2)
- Yield security – crop residue / surface thrash is buried so facilitates ease of sowing
- Disease control / weed control / (pest control)
what are the disadvantages of ploughing (5)
- Effect of soil biology – earthworms / beneficial insects
- Soil compaction / soil structure damage
- Soil erosion – very big problem on fragile topsoils worldwide
- High energy (fuel) and time requirements
- All of these disadvantages strongly support the search for alternative tillage techniques
what sort of seedbed is vital
fine firm and level
describe a fine seed bed
Fine
- good soil seed contact
- Residual weed control chemicals (herbicides) are more effective
- too fine : surface capping and reduced emergence
describe a firm seedbed (3)
Firm
- Good soil / seed contact
- More even sowing depth
- Better emergence
describe a level seedbed
Level
- More even sowing depth
- Uniform emergence
advantages of direct drilling/ No Till (4)
- time and energy saving
- minimises moisture losses
- organic matter retention (in top 5cm)
- reduction of erosion
what are the requirements for success for Direct Drilling/ No till
in high rainfall areas (Ireland) remove the straw and avoid surface compaction after wet harvests the move was to ‘rotational’ ploughing
what is reduced tillage/ Minimum tillage
cultivate the top 8-15 cm (+/- 80 mm ) of the soil layer
Non-inversion - soil is ‘mixed’
how much (%) is cost reduced using RT/MT
But what is increased?
lower costs (40-60%)
increased work rates
Advantages of MT/RT (3)
soil organic matter (soil carbon)
soil structure
more biological activity
what sort of seedbed is important for RT/MT
stale seedbed is very important
and also minimum surface compaction
what sort of challenges can there with with RT/MT in wet seasons (2)
Grass weed issues
crop establishment
what are other names for non inversion (4)
Min-till
Eco-till
Shallow till
Reduced till
what are techniques of eco-tillage/RT/MT (5)
- Straw Chopping / Removal
- Discing (shallow) x 2
- Rolling (consolidation)
- 2-3 weeks - stale seedbed - Glyphosate spraying (3 hours=)
- Seed Drilling (disc/wing control)
what % of grassweed control is gained with MT/RT compared to ploughing
MT/RT: 40-70% of grassweed control
Ploughing: 90% of grassweed control
what are the steps of conventional - plough/tillage/sow
- Harvest the cereal (crop)
- Bale / remove straw or chop /spread straw
- Plough / cultivate (till/power harrow) / sow
- one pass system (till+sow)
what are the conservation agriculture (eco-tillage/MT/RT)
- Harvest cereal and chop / spread the straw
- Shallow cultivate with discs / tines to 7.5 cm (5-10cm)
- Roll or press to produce fine firm ‘stale’ seedbed to encourage weed germination
- 3 weeks wait
- Spray the germinated weeds/ volunteer cereals (weeds) with glyphosate (Roundup)
- Sow with minimum soil disturbance
seedbed requirements (4)
- fine tilth
- residual herbicide effectiveness - porous above
- plant comes through easily - good seed:soil contact
- fine below - roots and water go down
what is the problem with rough seedbeds
its not possible to drill seed to uniform depth
what is the objective of the seedbed
to produce a good tilth
what does a seed bed need (5)
- Soil / water / air ratio
- Drainage
- Aeration (aerobic/ anaerobic)
- Root growth
- Soil Temperature
what is the preferred time of one pass system
autumn
one pass systems (4)
- preferred for autumn drilling
- typically seed only
- modest workrates
- slow drill speeds
what sort of drills is conventional seed drills
usually combine (seed + fertiliser) drills
what is the sowing depth and row spacing for seed drilling (drilling speed / seed spacing / depth of sowing)
sowing depth is in the range 2-2.5 cm
row spacing is in the range 10-15 cm
what was the difference between Min-till v Plough : Teagasc Oakpark 2000-2010 for winter wheat
Winter wheat showed little difference in yield when min-till and plough-based systems were compared, though both systems came out on top in different years depending on weather.
who was the main researcher for Min-till v Plough : Teagasc Oakpark 2000-2010
Dermot Forristal
what was the difference between Min-till v Plough : Teagasc Oakpark 2000-2010 for spring barley
For spring barley, the information is more limited, so I’d be more cautious about making pronouncements there. We do know that min-till does work well for that crop in certain soils, but research is ongoing
when teagasc researcher into the cost savings of min-till what id they conclude
that fuel consumption is more than halved, and with machinery costs following this, the overall costs come to approximately 60 percent of the costs of conventional ploughing.
due to interactions with weather, what does conventional tillage produce
more consistent grain yields and nitrogen use efficiencies
what has no effect on grain yield or NUE
STRAW RESIDUE MANAGEMENT
what had no effect on soil mineral nitrogen content
Soil tillage or residue management systems
